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[#]: collector: (lujun9972)
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[#]: translator: (beamrolling)
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[#]: reviewer: (wxy)
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[#]: publisher: (wxy)
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[#]: url: (https://linux.cn/article-11285-1.html)
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[#]: subject: (How to transition into a career as a DevOps engineer)
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||||
[#]: via: (https://opensource.com/article/19/7/how-transition-career-devops-engineer)
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||||
[#]: author: (Conor Delanbanque https://opensource.com/users/cdelanbanquehttps://opensource.com/users/daniel-ohhttps://opensource.com/users/herontheclihttps://opensource.com/users/marcobravohttps://opensource.com/users/cdelanbanque)
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如何转职为 DevOps 工程师
|
||||
======
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||||
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||||
> 无论你是刚毕业的大学生，还是想在职业中寻求进步的经验丰富的 IT 专家，这些提示都可以帮你成为 DevOps 工程师。
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||||
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DevOps 工程是一个备受称赞的热门职业。不管你是刚毕业正在找第一份工作，还是在利用之前的行业经验的同时寻求学习新技能的机会，本指南都能帮你通过正确的步骤成为 [DevOps 工程师][2]。
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### 让自己沉浸其中
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首先学习 [DevOps][3] 的基本原理、实践以及方法。在使用工具之前，先了解 DevOps 背后的“为什么”。DevOps 工程师的主要目标是在整个软件开发生命周期（SDLC）中提高速度并保持或提高质量，以提供最大的业务价值。阅读文章、观看 YouTube 视频、参加当地小组聚会或者会议 —— 成为热情的 DevOps 社区中的一员，在那里你将从先行者的错误和成功中学习。
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### 考虑你的背景
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如果你有从事技术工作的经历，例如软件开发人员、系统工程师、系统管理员、网络运营工程师或者数据库管理员，那么你已经拥有了广泛的见解和有用的经验，它们可以帮助你在未来成为 DevOps 工程师。如果你在完成计算机科学或任何其他 STEM（LCTT 译注：STEM 是<ruby>科学<rt>Science</rt></ruby>、<ruby>技术<rt>Technology</rt></ruby>、<ruby>工程<rt>Engineering</rt></ruby>和<ruby>数学<rt>Math</rt></ruby>四个学科的首字母缩略字）领域的学业后刚开始职业生涯，那么你将拥有在这个过渡期间需要的一些基本踏脚石。
|
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DevOps 工程师的角色涵盖了广泛的职责。以下是企业最有可能使用他们的三种方向：
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* **偏向于开发（Dev）的 DevOps 工程师**，在构建应用中扮演软件开发的角色。他们日常工作的一部分是利用持续集成 / 持续交付（CI/CD）、共享仓库、云和容器，但他们不一定负责构建或实施工具。他们了解基础架构，并且在成熟的环境中，能将自己的代码推向生产环境。
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* **偏向于运维技术（Ops）的 DevOps 工程师**，可以与系统工程师或系统管理员相比较。他们了解软件的开发，但并不会把一天的重心放在构建应用上。相反，他们更有可能支持软件开发团队实现手动流程的自动化，并提高人员和技术系统的效率。这可能意味着分解遗留代码，并用不太繁琐的自动化脚本来运行相同的命令，或者可能意味着安装、配置或维护基础结构和工具。他们确保为任何有需要的团队安装可使用的工具。他们也会通过教团队如何利用 CI / CD 和其他 DevOps 实践来帮助他们。
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* **网站可靠性工程师（SRE）**，就像解决运维和基础设施的软件工程师。SRE 专注于创建可扩展、高可用且可靠的软件系统。
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|
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在理想的世界中，DevOps 工程师将了解以上所有领域；这在成熟的科技公司中很常见。然而，顶级银行和许多财富 500 强企业的 DevOps 职位通常会偏向开发（Dev）或运营（Ops）。
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### 要学习的技术
|
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DevOps 工程师需要了解各种技术才能有效完成工作。无论你的背景如何，请从作为 DevOps 工程师需要使用和理解的基本技术开始。
|
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|
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#### 操作系统
|
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|
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操作系统是一切运行的地方，拥有相关的基础知识十分重要。[Linux][4] 是你最有可能每天使用的操作系统，尽管有的组织会使用 Windows 操作系统。要开始使用，你可以在家中安装 Linux，在那里你可以随心所欲地中断，并在此过程中学习。
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#### 脚本
|
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接下来，选择一门语言来学习脚本编程。有很多语言可供选择，包括 Python、Go、Java、Bash、PowerShell、Ruby 和 C / C++。我建议[从 Python 开始][5]，因为它相对容易学习和解释，是最受欢迎的语言之一。Python 通常是遵循面向对象编程（OOP）的准则编写的，可用于 Web 开发、软件开发以及创建桌面 GUI 和业务应用程序。
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#### 云
|
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|
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学习了 [Linux][4] 和 [Python][5] 之后，我认为下一个该学习的是云计算。基础设施不再只是“运维小哥”的事情了，因此你需要接触云平台，例如 AWS 云服务、Azure 或者谷歌云平台。我会从 AWS 开始，因为它有大量免费学习工具，可以帮助你降低作为开发人员、运维人员，甚至面向业务的部门的任何障碍。事实上，你可能会被它提供的东西所淹没。考虑从 EC2、S3 和 VPC 开始，然后看看你从其中想学到什么。
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|
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#### 编程语言
|
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|
||||
如果你对 DevOps 的软件开发充满热情，请继续提高你的编程技能。DevOps 中的一些优秀和常用的编程语言和你用于脚本编程的相同：Python、Go、Java、Bash、PowerShell、Ruby 和 C / C++。你还应该熟悉 Jenkins 和 Git / Github，你将会在 CI / CD 过程中经常使用到它们。
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#### 容器
|
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|
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最后，使用 Docker 和编排平台（如 Kubernetes）等工具开始学习[容器化][6]。网上有大量的免费学习资源，大多数城市都有本地的线下小组，你可以在友好的环境中向有经验的人学习（还有披萨和啤酒哦！）。
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#### 其他的呢？
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如果你缺乏开发经验，你依然可以通过对自动化的热情，提高效率，与他人协作以及改进自己的工作来[参与 DevOps][3]。我仍然建议学习上述工具，但重点不要放在编程 / 脚本语言上。了解基础架构即服务、平台即服务、云平台和 Linux 会非常有用。你可能会设置工具并学习如何构建具有弹性和容错能力的系统，并在编写代码时利用它们。
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|
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### 找一份 DevOps 的工作
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求职过程会有所不同，具体取决于你是否一直从事技术工作，是否正在进入 DevOps 领域，或者是刚开始职业生涯的毕业生。
|
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|
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#### 如果你已经从事技术工作
|
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|
||||
如果你正在从一个技术领域转入 DevOps 角色，首先尝试在你当前的公司寻找机会。你能通过和其他的团队一起工作来重新掌握技能吗？尝试跟随其他团队成员，寻求建议，并在不离开当前工作的情况下获得新技能。如果做不到这一点，你可能需要换另一家公司。如果你能从上面列出的一些实践、工具和技术中学习，你将能在面试时展示相关知识从而占据有利位置。关键是要诚实，不要担心失败。大多数招聘主管都明白你并不知道所有的答案；如果你能展示你一直在学习的东西，并解释你愿意学习更多，你应该有机会获得 DevOps 的工作。
|
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|
||||
#### 如果你刚开始职业生涯
|
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|
||||
申请雇用初级 DevOps 工程师的公司的空缺机会。不幸的是，许多公司表示他们希望寻找更富有经验的人，并建议你在获得经验后再申请该职位。这是“我们需要经验丰富的人”的典型，令人沮丧的场景，并且似乎没人愿意给你第一次机会。
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|
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然而，并不是所有求职经历都那么令人沮丧；一些公司专注于培训和提升刚从大学毕业的学生。例如，我工作的 [MThree][7] 会聘请应届毕业生并且对其进行 8 周的培训。当完成培训后，参与者们可以充分了解到整个 SDLC，并充分了解它在财富 500 强公司环境中的运用方式。毕业生被聘为 MThree 的客户公司的初级 DevOps 工程师 —— MThree 在前 18 - 24 个月内支付全职工资和福利，之后他们将作为直接雇员加入客户。这是弥合从大学到技术职业的间隙的好方法。
|
||||
|
||||
### 总结
|
||||
|
||||
转职成 DevOps 工程师的方法有很多种。这是一条非常有益的职业路线，可能会让你保持繁忙和挑战 — 并增加你的收入潜力。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/7/how-transition-career-devops-engineer
|
||||
|
||||
作者：[Conor Delanbanque][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[beamrolling](https://github.com/beamrolling)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/cdelanbanquehttps://opensource.com/users/daniel-ohhttps://opensource.com/users/herontheclihttps://opensource.com/users/marcobravohttps://opensource.com/users/cdelanbanque
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/hiring_talent_resume_job_career.png?itok=Ci_ulYAH (technical resume for hiring new talent)
|
||||
[2]: https://opensource.com/article/19/7/devops-vs-sysadmin
|
||||
[3]: https://opensource.com/resources/devops
|
||||
[4]: https://opensource.com/resources/linux
|
||||
[5]: https://opensource.com/resources/python
|
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[6]: https://opensource.com/article/18/8/sysadmins-guide-containers
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[7]: https://www.mthreealumni.com/
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@ -0,0 +1,65 @@
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[#]: collector: (lujun9972)
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[#]: translator: ( )
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[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Endless Grants $500,000 Fund To GNOME Foundation’s Coding Education Challenge)
|
||||
[#]: via: (https://itsfoss.com/endless-gnome-coding-education-challenge/)
|
||||
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
|
||||
|
||||
Endless Grants $500,000 Fund To GNOME Foundation’s Coding Education Challenge
|
||||
======
|
||||
|
||||
The [GNOME foundation][1] recently announced the “**Coding Education Challenge**“, which is a three-stage competition to offer educators and students the opportunity to share their innovative ideas (projects) to teach coding with free and open-source software.
|
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|
||||
For the funding (that covers the reward), [Endless][2] has issued a $500,000 (half a million) grant to support the competition and attract more educators/students from across the world. Yes, that is a whole lot of money to be awarded to the team (or individual) that wins the competition.
|
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|
||||
In case you didn’t know about **Endless**, here’s a background for you – _they work on increasing digital access to children and help them to make the most out of it while also educating them about it_. Among other projects, they have [Endless OS Linux distribution][3]. They also have [inexpensive mini PCs running Linux][4] to help their educational projects.
|
||||
|
||||
In the [press release][5], **Neil McGovern**, Executive Director, GNOME Foundation mentioned:
|
||||
|
||||
> “We’re very grateful that Endless has come forward to provide more opportunities for individuals to learn about free and open-source ”
|
||||
|
||||
He also added:
|
||||
|
||||
> “We’re excited to see what can be achieved when we empower the creativity and imagination of our global community. We hope to make powerful partnerships between students and educators to explore the possibilities of our rich and diverse software ecosystem. Reaching the next generation of developers is crucial to ensuring that free software continues for many years in the future.”
|
||||
|
||||
**Matt Dalio**, founder of Endless, also shared his thoughts about this competition:
|
||||
|
||||
> “We fully believe in GNOME’s mission of making technology available and providing the tools of digital agency to all. What’s so unique about the GNOME Project is that it delivers a fully-working personal computer system, which is a powerful real-world vehicle to teach kids to code. There are so many potential ways for this competition to build flourishing ecosystems that empower the next generation to create, learn and build.”
|
||||
|
||||
In addition to the announcement of competition and the grant, we do not have more details. However, anyone can submit a proposal for the competition (an individual or a team). Also, it has been decided that there will be 20 winners for the first round and will be rewarded **$6500** each for their ideas.
|
||||
|
||||
[][6]
|
||||
|
||||
Suggested read StationX Announces New Laptop Customized for Manjaro Linux
|
||||
|
||||
For the second stage of the competition, the winners will be asked to provide a working prototype from which 5 winners will be filtered to get **$25,000** each as the prize money.
|
||||
|
||||
In the final stage will involve making an end-product where only two winners will be selected. The runners up shall get **$25,000** and the winner walks away with **$100,000**.
|
||||
|
||||
_**Wrapping Up**_
|
||||
|
||||
I’d love to watch out for more details on ‘Coding Education Challenge’ by GNOME Foundation. We shall update this article for more details on the competition.
|
||||
|
||||
While the grant makes it look like a great initiative by GNOME Foundation, what do you think about it? Feel free to share your thoughts in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/endless-gnome-coding-education-challenge/
|
||||
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/ankush/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.gnome.org/
|
||||
[2]: https://endlessnetwork.com/
|
||||
[3]: https://endlessos.com/home/
|
||||
[4]: https://endlessos.com/computers/
|
||||
[5]: https://www.gnome.org/news/2019/08/gnome-foundation-launches-coding-education-challenge/
|
||||
[6]: https://itsfoss.com/stationx-manjaro-linux/
|
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88
sources/talk/20190828 VMware touts hyperscale SD-WAN.md
Normal file
88
sources/talk/20190828 VMware touts hyperscale SD-WAN.md
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@ -0,0 +1,88 @@
|
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[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (VMware touts hyperscale SD-WAN)
|
||||
[#]: via: (https://www.networkworld.com/article/3434619/vmware-touts-hyperscale-sd-wan.html)
|
||||
[#]: author: (Michael Cooney https://www.networkworld.com/author/Michael-Cooney/)
|
||||
|
||||
VMware touts hyperscale SD-WAN
|
||||
======
|
||||
VMware is teaming up with Dell/EMC to offer a hardware/software package rolled up into a managed SD-WAN service.
|
||||
BlueBay2014 / Getty Images
|
||||
|
||||
SAN FRANCISCO – VMware teamed with Dell/EMC this week to deliver an SD-WAN service that promises to greatly simplify setting up and supporting wide-area-network connectivity.
|
||||
|
||||
The Dell EMC SD-WAN Solution is a package of VMware software with Dell hardware and software that will be managed by Dell and sold as a package by both companies and their partners.
|
||||
|
||||
The package, introduced at the [VMworld event][1] here, includes VMware SD-WAN by VeloCloud software available as a subscription coupled with appliances available in multiple configurations capable of handling 10Mbps to 10Gbps of traffic, depending on customer need, said [Sanjay Uppal,][2] vice president and general manager of VMware’s VeloCloud Business Unit.
|
||||
|
||||
**More about SD-WAN**
|
||||
|
||||
* [How to buy SD-WAN technology: Key questions to consider when selecting a supplier][3]
|
||||
* [How to pick an off-site data-backup method][4]
|
||||
* [SD-Branch: What it is and why you’ll need it][5]
|
||||
* [What are the options for security SD-WAN?][6]
|
||||
|
||||
|
||||
|
||||
“The package is a much simpler way for customers to quickly set up a modern SD-WAN, especially for those customers who don’t have a lot of IT personnel to handle setting up and configuring an SD-WAN,” Uppal said. “Branch office networking can be complex and expensive, and this package uses subscription pricing, and supports cloud-like capabilities and economics.”
|
||||
|
||||
Dell EMC and VMware also announced SmartFabric Director, software that can be part of the service offering. Director enables data-center operators to build, operate and monitor an open network-underlay fabric based on Dell EMC PowerSwitch switches.
|
||||
|
||||
Accoding to Dell, organizations that have embraced overlay software-defined networks need to make sure their physical, underlay networks are tuned to work with the SDN. "A lack of visibility between the two layers can lead to provisioning and configuration errors, hampering network performance,” Dell stated.
|
||||
|
||||
The Director also supports flexible streaming telemetry to gather key operational data and statistics from the fabric switches it oversees, so customers can use it in security and other day-to-day operations, Dell said.
|
||||
|
||||
Analysts said the key to the VMware/Dell package isn’t so much the technology but the fact that it can be sold by so many of Dell and VMware’s partners.
|
||||
|
||||
"Dell will lead on the sales motion with an SD-WAN-as-a-Service offering leveraging its [customer premises equipment] platforms and global service and support capabilities, leveraging SD-WAN technology from VMware/VeloCloud,” said Rohit Mehra, vice president, Network Infrastructure for IDC.
|
||||
|
||||
VMware also used its VMworld event to say its VeloCloud SD-WAN platform and aggregate data gathered from customer networks will let the company offer more powerful network-health and control mechanisms in the future.
|
||||
|
||||
“The SD-WAN VMware/VeloCloud has actually achieved a milestone we think is significant across multiple dimensions, one is architecture. We have proven that we can get to tens of thousands of edges with a single network. In the aggregate, we are crossing 150,000 gateways, over 120 points-of-presence,” Uppal said.
|
||||
|
||||
VMware/Velocloud supports gateways across major cloud providers including Amazon Web Services, Microsoft Azure, Google Cloud Platform, and IBM Cloud as well as multiple carrier underlay networks.
|
||||
|
||||
“From all of those endpoints we can see how the underlay network is performing, what applications are running on it and security threat information. Right now we can use that information to help IT intervene and fix problems manually,” Uppal said. Long-term, the goal is to use the data to train algorithms that VMware is developing to promote self-healing networks that could, for example, detect outages and automatically reroute traffic around them.
|
||||
|
||||
The amount of data VMware gathers from cloud, branch-office and SD-WAN endpoints amounts to a treasure trove. “That is all part of the hyperscale idea," Uppal said.
|
||||
|
||||
There are a number of trends driving the increased use of SD-WAN technologies, Uppal said, a major one being the increased use of containers and cloud-based applications that need access from the edge. “The scope of clients needing SD-WAN service access to the data center or cloud resources is growing and changing rapidly,” he said.
|
||||
|
||||
In the most recent IDC [SD-WAN Infrastructure Forecast][7] report, Mehra wrote about a number of other factors driving SD-WAN evolution. For example:
|
||||
|
||||
* Traditional enterprise WANs are increasingly not meeting the needs of today's modern digital businesses, especially as it relates to supporting SaaS apps and multi- and hybrid-cloud usage.
|
||||
* Enterprises are interested in easier management of multiple connection types across their WAN to improve application performance and end-user experience.
|
||||
|
||||
|
||||
|
||||
“Combined with the rapid embrace of SD-WAN by leading communications service providers globally, these trends continue to drive deployments of SD-WAN, providing enterprises with dynamic management of hybrid WAN connections and the ability to guarantee high levels of quality of service on a per-application basis,” Mehra wrote in the report.
|
||||
|
||||
The report also said that the SD-WAN infrastructure market continues to be highly competitive with sales increasing 64.9% in 2018 to $1.37 billion. IDC stated Cisco holds the largest share of the SD-WAN infrastructure market, with VMware coming in second followed by Silver Peak, Nokia-Nuage, and Riverbed.
|
||||
|
||||
Join the Network World communities on [Facebook][8] and [LinkedIn][9] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3434619/vmware-touts-hyperscale-sd-wan.html
|
||||
|
||||
作者：[Michael Cooney][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Michael-Cooney/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.networkworld.com/article/3434576/vmware-boosts-load-balancing-security-intelligence-analytics.html
|
||||
[2]: https://www.networkworld.com/article/3387641/beyond-sd-wan-vmwares-vision-for-the-network-edge.html
|
||||
[3]: https://www.networkworld.com/article/3323407/sd-wan/how-to-buy-sd-wan-technology-key-questions-to-consider-when-selecting-a-supplier.html
|
||||
[4]: https://www.networkworld.com/article/3328488/backup-systems-and-services/how-to-pick-an-off-site-data-backup-method.html
|
||||
[5]: https://www.networkworld.com/article/3250664/lan-wan/sd-branch-what-it-is-and-why-youll-need-it.html
|
||||
[6]: https://www.networkworld.com/article/3285728/sd-wan/what-are-the-options-for-securing-sd-wan.html?nsdr=true
|
||||
[7]: https://www.idc.com/getdoc.jsp?containerId=prUS45380319
|
||||
[8]: https://www.facebook.com/NetworkWorld/
|
||||
[9]: https://www.linkedin.com/company/network-world
|
||||
@ -0,0 +1,59 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Data center-specific AI completes tasks twice as fast)
|
||||
[#]: via: (https://www.networkworld.com/article/3434597/data-center-specific-ai-completes-tasks-twice-as-fast.html)
|
||||
[#]: author: (Patrick Nelson https://www.networkworld.com/author/Patrick-Nelson/)
|
||||
|
||||
Data center-specific AI completes tasks twice as fast
|
||||
======
|
||||
Researchers at MIT have developed an artificial intelligence-powered system based on reinforcement learning that could revolutionize data center operations.
|
||||
Matejmo / Getty Images
|
||||
|
||||
Data centers running artificial intelligence (AI) will be significantly more efficient than those operating with hand-edited algorithm schedules, say experts at MIT. The researchers there say they have developed an automated scheduler that speeds cluster jobs by up to 20 or 30 percent, and even faster (2x) in peak periods.
|
||||
|
||||
The school’s AI job scheduler works on a type of AI called “reinforcement learning” (RL). That’s a trial-and-error-based machine-learning method that modifies scheduling decisions depending on actual workloads in a specific cluster. AI, when done right, could supersede the current state-of-the-art method, which is algorithms. They often must be fine-tuned by humans, introducing inefficiency.
|
||||
|
||||
“The system could enable data centers to handle the same workload at higher speeds, using fewer resources,” [the school says in a news article related to the tech][1]. The MIT researchers say the data center-adapted form of RL could revolutionize operations.
|
||||
|
||||
**Also read: [AI boosts data center availability and efficiency][2]**
|
||||
|
||||
“If you have a way of doing trial and error using machines, they can try different ways of scheduling jobs and automatically figure out which strategy is better than others,” says Hongzi Mao, a student in the university’s Department of Electrical Engineering and Computer Science, in the article. “Any slight improvement in utilization, even 1%, can save millions of dollars and a lot of energy.”
|
||||
|
||||
### What's wrong with today's data center algorithms
|
||||
|
||||
The problem with the current algorithms for running tasks on thousands of servers at the same time is that they’re not very efficient. Theoretically, they should be, but because workloads (combinations of tasks) are varied, humans get involved in tweaking the performance—a resource, say, might need to be shared between jobs, or some jobs might need to be performed faster than others—but humans can’t handle the range or scope of the edits; the job is just too big.
|
||||
|
||||
Unfathomable permutations for humans in the manually edited scheduling can include the fact that a lower node (smaller computational task) can’t start work until an upper node (larger, more power-requiring computational task) has completed its work. It gets highly complicated allocating the computational resources, the scientists explain.
|
||||
|
||||
Decima, MIT’s system, can process dynamic graphs (representations) of nodes and edges (edges connect nodes, linking tasks), the school says. That hasn’t been possible before with RL because RL hasn’t been able to understand the graphs well enough at scale.
|
||||
|
||||
“Traditional RL systems are not accustomed to processing such dynamic graphs,” MIT says.
|
||||
|
||||
MIT’s graph-oriented AI is different than other forms of AI that are more commonly used with images. Robots, for example, learn the difference between objects in different scenarios by processing images and getting reward signals when they get it right.
|
||||
|
||||
Similar, though, to presenting images to robots, workloads in the Decima system are mimicked until the system, through the receipt of AI reward signals, improves its decisions. A special kind of baselining (comparison to history) then helps Decima figure out which actions are good and which ones are bad, even when the workload sequences only supply poor reward signals due to the complication of the job structures slowing everything down. That baselining is a key differentiator in the MIT system.
|
||||
|
||||
“Decima can find opportunities for [scheduling] optimization that are simply too onerous to realize via manual design/tuning processes,” says Aditya Akella, a professor at University of Wisconsin at Madison, in the MIT article. The team there has developed a number of high-performance schedulers. “Decima can go a step further,” Akella says.
|
||||
|
||||
Join the Network World communities on [Facebook][3] and [LinkedIn][4] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3434597/data-center-specific-ai-completes-tasks-twice-as-fast.html
|
||||
|
||||
作者：[Patrick Nelson][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Patrick-Nelson/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: http://news.mit.edu/2019/decima-data-processing-0821
|
||||
[2]: https://www.networkworld.com/article/3274654/ai-boosts-data-center-availability-efficiency.html
|
||||
[3]: https://www.facebook.com/NetworkWorld/
|
||||
[4]: https://www.linkedin.com/company/network-world
|
||||
@ -0,0 +1,81 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Rating IoT devices to gauge their impact on your network)
|
||||
[#]: via: (https://www.networkworld.com/article/3435136/rating-iot-devices-to-gauge-their-impact-on-your-network.html)
|
||||
[#]: author: (Jon Gold https://www.networkworld.com/author/Jon-Gold/)
|
||||
|
||||
Rating IoT devices to gauge their impact on your network
|
||||
======
|
||||
With the wide range of internet of things devices being connected to business networks, there’s no cookie-cutter solution to building networks to support them, but assessing their needs can help.
|
||||
Natalya Burova / Getty Images
|
||||
|
||||
One difficulty designing [IoT][1] implementations is the large number of moving parts. Most IoT setups are built out of components from many different manufacturers – one company’s sensors here, another’s there, someone else handling the networking and someone else again making the backend.
|
||||
|
||||
To help you get a ballpark sense of what any given implementation will demand from your network, we’ve come up with a basic taxonomy for rating IoT endpoints. It’s got three main axes: delay tolerance, data throughput and processing power. Here is an explainer for each. (Terminology note: We’ll use “IoT setup” or “IoT implementation” to refer to the entirety of the IoT infrastructure being used by a given organization.)
|
||||
|
||||
**Learn about edge networking**
|
||||
|
||||
* [How edge networking and IoT will reshape data centers][2]
|
||||
* [Edge computing best practices][3]
|
||||
* [How edge computing can help secure the IoT][4]
|
||||
|
||||
|
||||
|
||||
### Delay tolerance
|
||||
|
||||
Many IoT implementation don’t require the millisecond-scale delay tolerance that traditional enterprise networks can provide, so that opens up a lot of network-connectivity options and means that going for a lower-priced choice could prove very successful.
|
||||
|
||||
For example, a connected parking meter doesn’t need to report its status to the city more than once a minute or so (if that), so a delay-inducing wireless option like [LoRaWAN][5] might be perfectly acceptable. Some systems of that type even use standard cellular SMS services to send updates back to central hubs.
|
||||
|
||||
For less delay-tolerant applications, like a production line or oil and gas extraction, industrial Ethernet or particularly low-latency wireless links should be used. Older-generation orchestration systems usually have the actual handling of instructions and coordination between machines well in hand, but adding real-time analytics data to the mix can increase network demands.
|
||||
|
||||
### Data throughput
|
||||
|
||||
Again, networking pros used to dealing with nothing less than megabits per second should adjust their expectations here, as there are plenty of IoT devices that require as little as a few kilobits per second or even less.
|
||||
|
||||
Devices with low-bandwidth requirements include smart-building devices such as connected door locks and light switches that mostly say “open” or “closed” or “on” or “off.”
|
||||
|
||||
Fewer demands on a given data link opens up the possibility of using less-capable wireless technology. Low-power WAN and Sigfox might not have the bandwidth to handle large amounts of traffic, but they are well suited for connections that don’t need to move large amounts of data in the first place, and they can cover significant areas. The range of Sigfox is 3 to 50 km depending on the terrain, and for Bluetooth, it’s 100 meters to 1,000 meters, depending on the class of Bluetooth being used.
|
||||
|
||||
Conversely, an IoT setup such as multiple security cameras connected to a central hub to a backend for image analysis will require many times more bandwidth. In such a case the networking piece of the puzzle will have to be more capable and, consequently, more expensive. Widely distributed devices could demand a dedicated [LTE][6] connection, for example, or perhaps even a microcell of their own for coverage.
|
||||
|
||||
Network World / IDG
|
||||
|
||||
### Processing power
|
||||
|
||||
The degree to which an IoT device is capable of doing its own processing is a somewhat indirect measurement of its impact on your network, to be sure, but it’s still relevant in terms of comparing it to other devices that perform a similar function. A device that’s constantly streaming raw data onto the network, without performing any meaningful analysis or shaping of its own, can be a bigger traffic burden than one that’s doing at least some of the work.
|
||||
|
||||
That’s not always the case, of course. Many less-capable devices won’t generate a lot of data with which to clog up whatever network connection they have, while some more-capable ones (let’s say industrial robots with a lot of inbuilt power to processing data they collect) might still generate plenty of traffic.
|
||||
|
||||
But the onboard computing power of a device is still relevant when comparing it to others that perform similar jobs, particularly in sectors like manufacturing and energy extraction where a lot of analysis has to be performed somewhere, whether it’s on the device, at the edge or at the back end.
|
||||
|
||||
It’s even more relevant in the context of an edge setup, where some or all of the data analysis is done on an [edge-gateway device][7] located close to the endpoints. These gateways can be a good choice when fairly complicated analysis has to be performed as close to real-time as possible. But edge gateways don’t have the same resources available as a full-on [data center][8] or cloud so the amount of work that can be done on the endpoint itself remains a crucial concern. Synthesizing raw information into analysis can mean less traffic that has to go on the network.
|
||||
|
||||
Join the Network World communities on [Facebook][9] and [LinkedIn][10] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3435136/rating-iot-devices-to-gauge-their-impact-on-your-network.html
|
||||
|
||||
作者：[Jon Gold][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Jon-Gold/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.networkworld.com/article/3207535/what-is-iot-how-the-internet-of-things-works.html
|
||||
[2]: https://www.networkworld.com/article/3291790/data-center/how-edge-networking-and-iot-will-reshape-data-centers.html
|
||||
[3]: https://www.networkworld.com/article/3331978/lan-wan/edge-computing-best-practices.html
|
||||
[4]: https://www.networkworld.com/article/3331905/internet-of-things/how-edge-computing-can-help-secure-the-iot.html
|
||||
[5]: https://www.networkworld.com/article/3235124/internet-of-things-definitions-a-handy-guide-to-essential-iot-terms.html
|
||||
[6]: https://www.networkworld.com/article/3432938/when-private-lte-is-better-than-wi-fi.html
|
||||
[7]: https://www.networkworld.com/article/3327197/edge-gateways-flexible-rugged-iot-enablers.html
|
||||
[8]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
|
||||
[9]: https://www.facebook.com/NetworkWorld/
|
||||
[10]: https://www.linkedin.com/company/network-world
|
||||
@ -0,0 +1,69 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (SparkFun continues to innovate thanks to open source hardware)
|
||||
[#]: via: (https://opensource.com/article/19/8/sparkfun-creator-nathan-seidle)
|
||||
[#]: author: (Don Watkins https://opensource.com/users/don-watkins)
|
||||
|
||||
SparkFun continues to innovate thanks to open source hardware
|
||||
======
|
||||
SparkFun founder Nathan Seidle says companies built around patents
|
||||
become "intellectually unfit" to innovate. Artemis, his new
|
||||
microprocessor for low-power devices, is just one example of the
|
||||
company's nimbleness.
|
||||
![SparkFun Redboard with Artemis][1]
|
||||
|
||||
When [SparkFun Electronics][2] founder and CEO Nathan Seidle was an engineering student at the University of Colorado, he was taught, "Real engineers come up with an idea and patent that idea." However, his experience with SparkFun, which he founded from his college apartment in 2003, is quite the opposite.
|
||||
|
||||
All 600 "SparkFun original" components are for sale on the site in addition to 1000+ resell products. All of the company's schematics and code are licensed under [CC BY-SA][3], with some firmware [CC0][4], and its design files are available on [public GitHub repos][5]. In addition, some of the company's designs are Open Source Hardware Association ([OSHWA][6]) certified.
|
||||
|
||||
Contrary to his college professor's lesson, Nathan sees patents as an anachronism that provide no guarantees to the companies and individuals who hold them. As he explained in a 2013 [TEDx Boulder talk][7], "If your idea can be sold, it will be," even if you have a patent.
|
||||
|
||||
"When a company relies too much on their intellectual property, they become intellectually unfit—they suffer from IP obesity," he says. "There have been numerous companies in history that have had long periods of prosperity only to be quickly left behind when technology shifted. Cloners are going to clone regardless of your business plan."
|
||||
|
||||
### Openness leads to innovation
|
||||
|
||||
Nathan says building a business on open hardware enables companies like SparkFun to innovate faster than those that are more concerned with defending their patents than developing new ideas.
|
||||
|
||||
Nathan says, "At the end of the day, by not relying on IP and patents, we've gotten stronger, more nimble, and built a more enduring business because of open source hardware." Nathan and SparkFun's 100 employees would rather spend their time innovating than litigating, he says.
|
||||
|
||||
His latest innovation is [Artemis][8], a new type of microprocessor module and the most complex thing he has ever designed.
|
||||
|
||||
![SparkFun and Artemis][9]
|
||||
|
||||
He hopes Artemis will enable users to design consumer-grade products and run anything from an Arduino sketch down to a bare-metal model for voice recognition.
|
||||
|
||||
"The Apollo 3 [integrated circuit] that powers Artemis is exceptionally powerful but also mind-bogglingly low power," he says. "At 0.5mA at 48MHz, it really changes the way you think about microcontrollers and low-power devices. Combine that low power with the push by Google to deploy TensorFlow light onto Artemis, and you've got the potential for battery-powered devices that can run machine learning algorithms for weeks on a single coin cell. It's all a bit mind-bending. We created a custom Arduino port from scratch in order to allow users to program Artemis with Arduino but not be limited to any toolchain."
|
||||
|
||||
### Building a sustainable business on open hardware
|
||||
|
||||
Because all of SparkFun's designs and hardware are open source, anyone can take the source files and copy, modify, sell, or do anything they like with them. SparkFun appreciates that people can take its innovations and use them in even more innovative ways, he says.
|
||||
|
||||
"Where many companies bury or open-wash themselves with the 'open source' banner, we like to brag we're two clicks away from the source files: a link on the product page will take you to the repo where you can immediately clone the repo and begin benefiting from our designs," Nathan says.
|
||||
|
||||
You may be wondering how a company can survive when everything is open and available. Nathan believes that open source is more than sustainable. He says it is a necessity given the rapid pace of change. A culture of sharing and openness can mitigate a lot of problems that more closed companies suffer. He says, "We need to avoid the mistakes that others have made, and the only way to do that is to talk openly and share in our mistakes."
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/sparkfun-creator-nathan-seidle
|
||||
|
||||
作者：[Don Watkins][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/don-watkins
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/sparkfun_redboard_artemis.jpg?itok=XGRU-VUF (SparkFun Redboard with Artemis)
|
||||
[2]: https://www.sparkfun.com/
|
||||
[3]: https://creativecommons.org/licenses/by-sa/2.0/
|
||||
[4]: https://creativecommons.org/publicdomain/zero/1.0/
|
||||
[5]: https://github.com/sparkfun
|
||||
[6]: https://www.oshwa.org/
|
||||
[7]: https://www.youtube.com/watch?v=xGhj_lLNtd0
|
||||
[8]: https://www.sparkfun.com/artemis
|
||||
[9]: https://opensource.com/sites/default/files/uploads/sparkfun_artemis_module_-_low_power_machine_learning_ble_cortex-m4f.jpg (SparkFun and Artemis)
|
||||
@ -0,0 +1,107 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (11 surprising ways you use Linux every day)
|
||||
[#]: via: (https://opensource.com/article/19/8/everyday-tech-runs-linux)
|
||||
[#]: author: (Don Watkins https://opensource.com/users/don-watkinshttps://opensource.com/users/rgb-eshttps://opensource.com/users/sethhttps://opensource.com/users/ansilvahttps://opensource.com/users/scottnesbitt)
|
||||
|
||||
11 surprising ways you use Linux every day
|
||||
======
|
||||
What technology runs on Linux? You might be astonished to know just how
|
||||
often you use Linux in your daily life.
|
||||
![Truck steering wheel and dash][1]
|
||||
|
||||
Linux runs almost everything these days, but many people are not aware of that. Some might be aware of Linux and might have heard that this operating system runs supercomputers. According to [Top500][2], Linux now powers the five-hundred fastest computers in the world. Go to their site and [search for "Linux"][3] to see the results for yourself.
|
||||
|
||||
### NASA runs on Linux
|
||||
|
||||
You might not be aware that Linux powers NASA. NASA’s [Pleiades][4] supercomputer runs Linux. The International Space Station [switched from Windows to Linux][5] six years ago due to the operating system's reliability. NASA even recently deployed three "Astrobee" robots—which [run Linux][6]—to the International Space Station.
|
||||
|
||||
### eReaders run on Linux
|
||||
|
||||
I read a great deal, and my go-to device is the Amazon Kindle Paperwhite, which runs Linux (though most people are completely unaware of that fact). If you use any of Amazon’s services—from [Amazon Elastic Compute Cloud (Amazon EC2)][7] to Fire TV—you are running on Linux. When you ask Alexa what time it is, or for the score of your favorite sports team, you are also using Linux, since Alexa is powered by [Fire OS][8] (an Android-based operating system). In fact, [Android][9] was developed by Google as Linux for mobile handsets, and [powers 76%][10] of today’s mobile phones.
|
||||
|
||||
### TV runs on Linux
|
||||
|
||||
If you have a [TiVo][11], you are also running Linux. If you are a Roku user, then you too are using Linux. [Roku OS][12] is a custom version of Linux specifically for Roku devices. You may opt to use Chromecast—which runs on Linux—for video streaming. Linux doesn’t just power set-top boxes and streaming devices, though. It likely runs your smart TV, too. LG uses webOS, which is based on the Linux kernel. Panasonic uses Firefox OS, which is also based on the Linux kernel. Samsung, Phillips, and many more use Linux-based operating systems to power their devices.
|
||||
|
||||
### Smartwatches and laptops run on Linux
|
||||
|
||||
If you own a smartwatch, it’s likely running Linux. School systems throughout the world have been implementing [one-to-one systems][13] where each child is provided their own laptop. A rapidly increasing number of those institutions outfit their students with a Chromebook. These lightweight laptops use [Chrome OS][14], which is based on Linux.
|
||||
|
||||
### Cars run on Linux
|
||||
|
||||
The car you drive might well be running Linux. [Automotive-Grade Linux][15] has enlisted manufacturers like Toyota, Mazda, Mercedes-Benz, and Volkswagen in a project that will see Linux as the standard code base for automobiles. It is also likely that your [in-vehicle infotainment][16] system runs Linux. The [GENIVI Alliance][17] develops "standard approaches for integrating operating systems and middleware present in the centralized and connected vehicle cockpit," according to its website.
|
||||
|
||||
### Gaming runs on Linux
|
||||
|
||||
If you are a gamer, then you might be using [SteamOS][18], which is a Linux-based operating system. Also, if you use any of Google’s myriad of services, then you are running on Linux.
|
||||
|
||||
### Social media runs on Linux
|
||||
|
||||
As you're scrolling and commenting, you may realize what a lot of work these platforms are doing. Perhaps then it's not so surprising that Instagram, Facebook, YouTube, and Twitter all run on Linux.
|
||||
|
||||
Additionally, the new wave of social media, de-centralized, federated nodes of connected communities like [Mastodon][19], [GNU Social][20], [Nextcloud][21] (microblogging platforms similar to Twitter), [Pixelfed][22] (distributed photo sharing), and [Peertube][23] (distributed video sharing) are, at least by default, run on Linux. Being open source, they can each run on any platform, which is a powerful precedence in itself.
|
||||
|
||||
### Businesses and governments run on Linux
|
||||
|
||||
The New York Stock Exchange runs on Linux, as does the Pentagon. The Federal Aviation Administration handles over sixteen million flights a year, and they operate on Linux. The Library of Congress, House of Representatives, Senate, and White House all use Linux.
|
||||
|
||||
### Retail runs on Linux
|
||||
|
||||
That entertainment system in the seat back on your latest flight is likely running on Linux. It’s possible that the point of sale at your favorite store is running Linux. [Tizen OS][24], which is based on Linux, powers an array of smart home and other smart devices. Many public libraries now host their integrated library systems on [Evergreen][25] and [Koha][26]. Both of those systems run on Linux.
|
||||
|
||||
### Apple runs on Linux
|
||||
|
||||
If you are an iOS user who uses [iCloud][27], then you, too, are using a system that runs on Linux. Apple Computer’s company website runs on Linux. If you would like to know what other websites are run on Linux, be sure to use [Netcraft][28] and check the results of "What’s that site running?"
|
||||
|
||||
### Routers run on Linux
|
||||
|
||||
It is possible that the router that connects you to the internet in your home is running Linux. If your current router is _not_ running Linux and you would like to change that, here is an [excellent how-to][29].
|
||||
|
||||
_As you can see, in many ways, Linux powers today’s world. What else might people not realize runs on Linux? Let us know in the comments._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/everyday-tech-runs-linux
|
||||
|
||||
作者：[Don Watkins][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/don-watkinshttps://opensource.com/users/rgb-eshttps://opensource.com/users/sethhttps://opensource.com/users/ansilvahttps://opensource.com/users/scottnesbitt
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/truck_steering_wheel_drive_car_kubernetes.jpg?itok=0TOzve80 (Truck steering wheel and dash)
|
||||
[2]: https://www.top500.org/
|
||||
[3]: https://www.top500.org/statistics/sublist/
|
||||
[4]: https://www.nas.nasa.gov/hecc/resources/pleiades.html
|
||||
[5]: https://www.extremetech.com/extreme/155392-international-space-station-switches-from-windows-to-linux-for-improved-reliability
|
||||
[6]: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180003515.pdf
|
||||
[7]: https://aws.amazon.com/amazon-linux-ami/
|
||||
[8]: https://en.wikipedia.org/wiki/Fire_OS
|
||||
[9]: https://en.wikipedia.org/wiki/Android_(operating_system)
|
||||
[10]: https://gs.statcounter.com/os-market-share/mobile/worldwide/
|
||||
[11]: https://tivo.pactsafe.io/legal.html#open-source-software
|
||||
[12]: https://en.wikipedia.org/wiki/Roku
|
||||
[13]: https://en.wikipedia.org/wiki/One-to-one_computing
|
||||
[14]: https://en.wikipedia.org/wiki/Chrome_OS
|
||||
[15]: https://opensource.com/life/16/8/agl-provides-common-open-code-base
|
||||
[16]: https://opensource.com/business/16/5/interview-alison-chaiken-steven-crumb
|
||||
[17]: https://www.genivi.org/faq
|
||||
[18]: https://store.steampowered.com/steamos/
|
||||
[19]: https://opensource.com/article/17/4/guide-to-mastodon
|
||||
[20]: https://www.gnu.org/software/social/
|
||||
[21]: https://apps.nextcloud.com/apps/social
|
||||
[22]: https://pixelfed.org/
|
||||
[23]: https://joinpeertube.org/en/
|
||||
[24]: https://wiki.tizen.org/Devices
|
||||
[25]: https://evergreen-ils.org/
|
||||
[26]: https://koha-community.org/
|
||||
[27]: https://toolbar.netcraft.com/site_report?url=https://www.icloud.com/
|
||||
[28]: https://www.netcraft.com/
|
||||
[29]: https://opensource.com/life/16/6/why-i-built-my-own-linux-router
|
||||
94
sources/talk/20190830 7 rules for remote-work sanity.md
Normal file
94
sources/talk/20190830 7 rules for remote-work sanity.md
Normal file
@ -0,0 +1,94 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (7 rules for remote-work sanity)
|
||||
[#]: via: (https://opensource.com/article/19/8/rules-remote-work-sanity)
|
||||
[#]: author: (Mike Bursell https://opensource.com/users/mikecamel)
|
||||
|
||||
7 rules for remote-work sanity
|
||||
======
|
||||
These rules don't describe my complete practice, but they are an
|
||||
important summary of what I try to do and what keeps me (relatively)
|
||||
sane.
|
||||
![Coding on a computer][1]
|
||||
|
||||
I work remotely and have done so on and off for a good percentage of the past 10 to 15 years. I'm lucky that I'm in a role where this suits my responsibilities, and in a company that is set up for it. Not all roles—those with many customer onsite meetings or those with a major service component—are suited to remote working, of course. But it's clear that an increasing number of organisations are considering having at least some of their workers doing so remotely.
|
||||
|
||||
I've carefully avoided using the phrase either "working from home" or "working at home" above. I've seen discussions that the latter gives a better "vibe" for some reason, but it's not accurate for many remote workers. In fact, it doesn't describe my role perfectly, either. My role is remote, in that I have no company-provided "base"—with a chair, desk, meeting rooms, phone, internet access, etc.—but I don't spend all of my time at home. I spend maybe one-and-a-half weeks a month, on average, travelling—to attend or speak at conferences, to have face-to-face ("F2F") meetings, etc. During these times, I'm generally expected to be contactable and to keep at least vaguely up-to-date on email—although the exact nature of the activities in which I'm engaged, and the urgency of the contacts and email, may increase or reduce my engagement.
|
||||
|
||||
### Open source
|
||||
|
||||
One of the reasons I can work remotely is that I work for a company that works with open source software. I'm currently involved in a very exciting project called [Enarx][2] (which I [announced][3] in May). We have contributors in Europe and the US and interest from further abroad. Our stand-ups are all virtual, and we default to turning on video. At least two of our regulars participate from a treadmill, I will typically stand at my desk. We use GitHub for all our code (it's all open source, of course), and there's basically no reason for us to meet in person very often. We try to celebrate together—agreeing to get cake, wherever we are, to mark special occasions, for instance—and have laptop stickers to brand ourselves and help team unity. We have a shared chat and IRC channel and spend a lot of time communicating via different channels. We're still quite a small team, but it works for now.
|
||||
|
||||
If you're looking for more tips about how to manage, coordinate, and work in remote teams, particularly around open source projects, you'll find lots of [information][4] online.
|
||||
|
||||
### The environment
|
||||
|
||||
When I'm not travelling around the place, I'm based at home. There, I have a commute—depending on weather conditions—of around 30-45 seconds, which is generally pretty bearable. My office is separate from the rest of the house (set in the garden) and outfitted with an office chair, desk, laptop dock, monitor, webcam, phone, keyboard, and printer; these are the obvious work-related items in the room.
|
||||
|
||||
Equally important, however, are the other accoutrements that make for a good working environment. These will vary from person to person, but I also have:
|
||||
|
||||
* A Sonos attached to an amplifier and good speakers
|
||||
* A sofa, often occupied by my dog and sometimes one of the cats
|
||||
* A bookshelf where the books that aren't littering the floor reside
|
||||
* Tea-making facilities (I'm British; this is important)
|
||||
* A fridge filled with milk (for the tea), beer, and wine (don't worry: I don't drink these during work hours, and it's more that the fridge is good for "overflow" from our main kitchen one)
|
||||
* Wide-opening windows and blinds for the summer (we have no air-conditioning; I'm British, remember?)
|
||||
* Underfloor heating _and_ a wood-burning stove for the winter (the former to keep the room above freezing until I get the latter warmed up)
|
||||
* A "[NUC][5]" computer and monitor for activities that aren't specifically work-related
|
||||
* A few spiders
|
||||
|
||||
|
||||
|
||||
What you have will depend on your work style, but these "non-work" items are important (bar the spiders, possibly) to my comfort and work practice. For instance, I often like to listen to music to help me concentrate; I often sit on the sofa with the dog and cats to read long documents; and without the fridge and tea-making facilities, I might as well be American.[1][6]
|
||||
|
||||
### My rules
|
||||
|
||||
How does it work, then? Well, first of all, most of us like human contact from time to time. Some remote workers rent space in a shared work environment and work there most of the time; they prefer an office environment or don't have a dedicated space for working at home. Others will mainly work in coffee shops or on their boat,[2][7] or they may spend half of the year in the office and the other half working from a second home. Whatever you do, finding something that works for you is important. Here's what I tend to do, and why:
|
||||
|
||||
1. **I try to have fairly rigid work hours.** Officially (and as advertised on our intranet for the information of colleagues), I work 10am-6pm UK time. This gives me a good overlap with the US (where many of my colleagues are based) and time in the morning to go for a run or a cycle and/or to walk the dog (see below). I don't always manage these times, but when I flex outward in one direction, I attempt to pull some time back the other way, as otherwise I know I'll just work ridiculous hours.
|
||||
2. **I ensure that I get up and have a cup of tea.** In an office environment, I would typically be interrupted from time to time by conversations, invitations to get tea, physical meetings in meeting rooms, lunch trips, etc. This doesn't happen at home, so it's important to keep moving, or you'll be stuck at your desk frequently for three to four hours at a time. This isn't good for your health or often for your productivity (and I enjoy drinking tea).
|
||||
3. **I have an app that tells me when I've been inactive.** This is new for me, but I like it. If I've basically not moved for an hour, my watch (could be a phone or laptop) tells me to do some exercise. It even suggests something, but I'll often ignore that and get up for some tea, for instance.[3][8]
|
||||
4. **I use my standing desk's up/down capability.** I try to vary my position through the day from standing to sitting and back again. It's good for posture and keeps me more alert.
|
||||
5. **I walk the dog.** If I need to get out of my office and do some deep thinking (or just escape a particularly painful email thread!), I'll take the dog for a walk. Even if I'm not thinking about work for the entire time, I know it'll make me more productive, and if it's a longish walk, I'll make sure I compensate by spending extra time working (which is always easy).
|
||||
6. **I have family rules.** The family knows that when I'm in my office, I'm at work. They can message me on my phone (which I may ignore) or may come to the window to see if I'm available, but if I'm not, I'm not. Emergencies (lack of milk for tea, for example) can be negotiated on a case-by-case basis.
|
||||
7. **I go for tea (and usually cake) at a cafe.** Sometimes, I need to get into a different environment and have a chat with actual people. For me, popping into the car for 10 minutes and going to a cafe is the way to do this. I've found one that makes good cakes (and tea).
|
||||
|
||||
|
||||
|
||||
These rules don't describe my complete practice, but they are an important summary of what I try to do and what keeps me (relatively) sane. Your rules will be different, but I think it's really important to _have_ rules and to make it clear to yourself, your colleagues, your friends, and your family what they are. Remote working is not always easy and requires discipline—but that discipline, more often than not, is in giving yourself some slack, rather than making yourself sit down for eight hours a day.
|
||||
|
||||
* * *
|
||||
|
||||
1\. I realise that many people, including many of my readers, are American. That's fine: you be you. I actively _like_ tea, however (and know how to make it properly, which seems to be an issue when I visit the US).
|
||||
2\. I know a couple of these: lucky, lucky people!
|
||||
3\. Can you spot a pattern?
|
||||
|
||||
* * *
|
||||
|
||||
_This article was originally published on [Alice, Eve, and Bob][9] and is reprinted with the author's permission._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/rules-remote-work-sanity
|
||||
|
||||
作者：[Mike Bursell][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/mikecamel
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_laptop_hack_work.png?itok=aSpcWkcl (Coding on a computer)
|
||||
[2]: https://enarx.io/
|
||||
[3]: https://opensource.com/article/19/5/enarx-security
|
||||
[4]: https://opensource.com/sitewide-search?search_api_views_fulltext=remote%20work
|
||||
[5]: https://en.wikipedia.org/wiki/Next_Unit_of_Computing
|
||||
[6]: tmp.S5SfsQZWG4#1
|
||||
[7]: tmp.S5SfsQZWG4#2
|
||||
[8]: tmp.S5SfsQZWG4#3
|
||||
[9]: https://aliceevebob.com/2019/08/13/my-7-rules-for-remote-work-sanity/
|
||||
@ -0,0 +1,113 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Bluetooth finds a role in the industrial internet of things)
|
||||
[#]: via: (https://www.networkworld.com/article/3434526/bluetooth-finds-a-role-in-the-industrial-internet-of-things.html)
|
||||
[#]: author: (Fredric Paul https://www.networkworld.com/author/Fredric-Paul/)
|
||||
|
||||
Bluetooth finds a role in the industrial internet of things
|
||||
======
|
||||
Market awareness and penetration, plus new technological advancements, are making Bluetooth—yes, Bluetooth—a key networking technology for the IIoT.
|
||||
Michael Brown / IDG
|
||||
|
||||
Like most people, I think of Bluetooth as a useful but consumer-oriented technology that lets me make easy wireless connections from my smartphone to various headsets, portable speakers, automobile, and other devices. And, of course, billions of people rely on Bluetooth for exactly those capabilities. But according to [Chuck Sabin][1], senior director of market development for the [Bluetooth SIG][2], the technology is growing into a key role in the industrial internet of things (IIoT).
|
||||
|
||||
Sabin says, Bluetooth “technology is actually well-suited for both consumer and enterprise markets.” He cites Bluetooth’s easy-to-implement low-power connections. More importantly, though, Bluetooth is ubiquitous, enjoying 90% global awareness and global, multi-vendor interoperability.
|
||||
|
||||
Bluetooth offers low deployment costs and massive economies of scale because it’s already built into virtually every new smartphone, tablet, and personal computer, not to mention a wide variety of wearables, smart speakers, and other devices, notes Sabin. That means IIoT deployments leveraging Bluetooth may be able to avoid having to build a completely proprietary solution to start using wireless systems in smart-building and smart-industry environments.
|
||||
|
||||
**[ Learn more [Download a PDF bundle of five essential articles about IoT in the enterprise][3] ]**
|
||||
|
||||
### 3 things driving Bluetooth adoption in IIoT?
|
||||
|
||||
In addition to Bluetooth’s deep market penetration, Sabin cites three notable technical advancements that are driving Bluetooth adoption in industrial and enterprise IoT applications:
|
||||
|
||||
1. **“The introduction of [Bluetooth 5][4] in 2016 was all about flexibility,”** Sabin explains. Bluetooth 5’s longer range and higher speeds provide the crucial flexibility necessary to support more reliable connections in a wide variety of large, noisy environments, like those of industrial or commercial spaces. For example, Sabin says, “a warehouse is a much different environment than the basement of a nuclear power plant. One is open and requires long-range connections, and the other is a more complex environment with a lot of interference, requiring a reliable connection or device network that can deliver information despite the noise.”
|
||||
|
||||
2. **[Bluetooth mesh][5], released In July of 2017, extends the [Bluetooth Core Specification][6] to enable “industrial-grade” many-to-many communication,** Sabin says, where tens, hundreds, and even thousands of devices can reliably and securely communicate with one another. “Bluetooth mesh networks are ideally suited for control, monitoring, and automation systems,” Sabin claims, and can also reduce latency and improve security.
|
||||
|
||||
3. **More recently, the Bluetooth SIG announced a new [direction-finding feature][7]** **for Bluetooth,** bringing even greater precision to location-services systems used in industrial and enterprise settings. [Bluetooth low energy][8] introduced the ability to roughly determine the location of a Bluetooth device by comparing signal strength between the device being located and the tracking device, at what Sabin calls a “fairly broad—“the device is in this room”—level of accuracy. This led to inexpensive, mass-market indoor location and asset tracking solutions.
|
||||
|
||||
The new direction-finding feature makes this much more precise: “Not only is the device in a specific room, but it’s in the back, left corner,” he says. And the Bluetooth SIG is working to add distance to this feature, so users will know whether “the device is in this specific room, in the back, left the corner, and 30 feet from me right now.” This level of precision will enable new applications, including monitoring for safety and security, Sabin says: for example, helping keep workers out of a toxic environment.
|
||||
|
||||
|
||||
|
||||
|
||||
### IioT Bluetooth use cases
|
||||
|
||||
Put all those developments together, and you enable device networks, Sabin says, where interconnected networks of devices are used to control lighting systems, sensor networks, and asset management solutions.
|
||||
|
||||
The Bluetooth SIG divides smart buildings and smart industry into three primary categories:
|
||||
|
||||
1. **Building automation:** The centralized automation of a factory’s essential systems—including lighting, heating, ventilation, and air conditioning (HVAC) and security—which can help conserve energy, lower operating costs, and improve the life cycle of a building’s core systems.
|
||||
2. **Condition monitoring:** Bluetooth sensor networks deployed across a factory floor or throughout an office building enable real-time monitoring of system performance to make maintenance, updating, and overall management more efficient.
|
||||
3. **Location services:** This can take on many forms, from wayfinding to asset tracking/management to indoor positioning and location and logistics solutions.
|
||||
|
||||
|
||||
|
||||
Use cases in manufacturing include helping manufacturers better monitor location, availability, and condition of equipment and output across the supply chain, Sabin says. Using enterprise wearables is helping manufacturers improve material management and process flow. Bluetooth location services are employing beacons to boost safety and security in chemical and manufacturing plants by creating geo-fences for restricted access and tracking numbers of employees in critical areas.
|
||||
|
||||
**[ [Take this mobile device management course from PluralSight and learn how to secure devices in your company without degrading the user experience.][9] ]**
|
||||
|
||||
Bluetooth Mesh was actually designed with connected lighting in mind, Sabin says, enabling everything from connected lighting in building automation to what he called [Lighting-as-a Platform (LaaP)][10] for deploying these services.
|
||||
|
||||
### Fast growth for Bluetooth in the IIoT
|
||||
|
||||
Based on these trends and advancements, the Bluetooth SIG’s recent [Bluetooth Market Update][11] predicts a 7x growth in annual shipments of Bluetooth smart-building location services devices by 2023, with 374 million Bluetooth smart-building devices shipping that year. The update also sees a 5x growth in annual shipments of Bluetooth smart-industry devices by 2023. These shipments are growing at of 47% a year, Sabin says, and will account for 70% of market shipments in 2023. The report also forecasts a 3.5x increase in shipments of Bluetooth enterprise wearables for smart industry use cases by 2023, with a 28% annual growth rate over the next five years.
|
||||
|
||||
That’s only if everything goes as planned, of course. Sabin warns that industrial and enterprise organizations often adopt new technology relatively slowly, looking for clear ROIs that may not always be fully fleshed out for new technologies. And, yes, no doubt some decision makers still think of Bluetooth as a short-range, point-to-point, consumer-grade technology not ready for enterprise and industrial environments.
|
||||
|
||||
**More about IoT:**
|
||||
|
||||
* [What is the IoT? How the internet of things works][12]
|
||||
* [What is edge computing and how it’s changing the network][13]
|
||||
* [Most powerful Internet of Things companies][14]
|
||||
* [10 Hot IoT startups to watch][15]
|
||||
* [The 6 ways to make money in IoT][16]
|
||||
* [What is digital twin technology? [and why it matters]][17]
|
||||
* [Blockchain, service-centric networking key to IoT success][18]
|
||||
* [Getting grounded in IoT networking and security][3]
|
||||
* [Building IoT-ready networks must become a priority][19]
|
||||
* [What is the Industrial IoT? [And why the stakes are so high]][20]
|
||||
|
||||
|
||||
|
||||
Join the Network World communities on [Facebook][21] and [LinkedIn][22] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3434526/bluetooth-finds-a-role-in-the-industrial-internet-of-things.html
|
||||
|
||||
作者：[Fredric Paul][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Fredric-Paul/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.linkedin.com/in/chucksabin/
|
||||
[2]: https://www.bluetooth.com/about-us/
|
||||
[3]: https://www.networkworld.com/article/3269736/internet-of-things/getting-grounded-in-iot-networking-and-security.html
|
||||
[4]: https://www.bluetooth.com/bluetooth-resources/bluetooth-5-go-faster-go-further/
|
||||
[5]: https://www.bluetooth.com/media/mesh-kit/
|
||||
[6]: https://www.bluetooth.com/specifications/bluetooth-core-specification/
|
||||
[7]: https://www.bluetooth.com/media/location-services/
|
||||
[8]: https://en.wikipedia.org/wiki/Bluetooth_Low_Energy
|
||||
[9]: https://pluralsight.pxf.io/c/321564/424552/7490?u=https%3A%2F%2Fwww.pluralsight.com%2Fcourses%2Fmobile-device-management-big-picture
|
||||
[10]: https://www.bluetooth.com/blog/lighting-as-a-platform-part-1/
|
||||
[11]: https://www.bluetooth.com/bluetooth-resources/2019-bluetooth-market-update/?utm_campaign=bmu&utm_source=internal&utm_medium=pr&utm_content=2019bmu-pr-outreach-ink
|
||||
[12]: https://www.networkworld.com/article/3207535/internet-of-things/what-is-the-iot-how-the-internet-of-things-works.html
|
||||
[13]: https://www.networkworld.com/article/3224893/internet-of-things/what-is-edge-computing-and-how-it-s-changing-the-network.html
|
||||
[14]: https://www.networkworld.com/article/2287045/internet-of-things/wireless-153629-10-most-powerful-internet-of-things-companies.html
|
||||
[15]: https://www.networkworld.com/article/3270961/internet-of-things/10-hot-iot-startups-to-watch.html
|
||||
[16]: https://www.networkworld.com/article/3279346/internet-of-things/the-6-ways-to-make-money-in-iot.html
|
||||
[17]: https://www.networkworld.com/article/3280225/internet-of-things/what-is-digital-twin-technology-and-why-it-matters.html
|
||||
[18]: https://www.networkworld.com/article/3276313/internet-of-things/blockchain-service-centric-networking-key-to-iot-success.html
|
||||
[19]: https://www.networkworld.com/article/3276304/internet-of-things/building-iot-ready-networks-must-become-a-priority.html
|
||||
[20]: https://www.networkworld.com/article/3243928/internet-of-things/what-is-the-industrial-iot-and-why-the-stakes-are-so-high.html
|
||||
[21]: https://www.facebook.com/NetworkWorld/
|
||||
[22]: https://www.linkedin.com/company/network-world
|
||||
@ -0,0 +1,341 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Getting started with HTTPie for API testing)
|
||||
[#]: via: (https://opensource.com/article/19/8/getting-started-httpie)
|
||||
[#]: author: (Moshe Zadka https://opensource.com/users/moshezhttps://opensource.com/users/mkalindepauleduhttps://opensource.com/users/jamesf)
|
||||
|
||||
Getting started with HTTPie for API testing
|
||||
======
|
||||
Debug API clients with HTTPie, an easy-to-use command-line tool written
|
||||
in Python.
|
||||
![Raspberry pie with slice missing][1]
|
||||
|
||||
[HTTPie][2] is a delightfully easy to use and easy to upgrade HTTP client. Pronounced "aitch-tee-tee-pie" and run as **http**, it is a command-line tool written in Python to access the web.
|
||||
|
||||
Since this how-to is about an HTTP client, you need an HTTP server to try it out; in this case, [httpbin.org][3], a simple, open source HTTP request-and-response service. The httpbin.org site is a powerful way to test to test web API clients and carefully manage and show details in requests and responses, but for now we will focus on the power of HTTPie.
|
||||
|
||||
### An alternative to Wget and cURL
|
||||
|
||||
You might have heard of the venerable [Wget][4] or the slightly newer [cURL][5] tools that allow you to access the web from the command line. They were written to access websites, whereas HTTPie is for accessing _web APIs_.
|
||||
|
||||
Website requests are designed to be between a computer and an end user who is reading and responding to what they see. This doesn't depend much on structured responses. However, API requests make _structured_ calls between two computers. The human is not part of the picture, and the parameters of a command-line tool like HTTPie handle this effectively.
|
||||
|
||||
### Install HTTPie
|
||||
|
||||
There are several ways to install HTTPie. You can probably get it as a package for your package manager, whether you use **brew**, **apt**, **yum**, or **dnf**. However, if you have configured [virtualenvwrapper][6], you can own your own installation:
|
||||
|
||||
|
||||
```
|
||||
$ mkvirtualenv httpie
|
||||
...
|
||||
(httpie) $ pip install httpie
|
||||
...
|
||||
(httpie) $ deactivate
|
||||
$ alias http=~/.virtualenvs/httpie/bin/http
|
||||
$ http -b GET <https://httpbin.org/get>
|
||||
{
|
||||
"args": {},
|
||||
"headers": {
|
||||
"Accept": "*/*",
|
||||
"Accept-Encoding": "gzip, deflate",
|
||||
"Host": "httpbin.org",
|
||||
"User-Agent": "HTTPie/1.0.2"
|
||||
},
|
||||
"origin": "104.220.242.210, 104.220.242.210",
|
||||
"url": "<https://httpbin.org/get>"
|
||||
}
|
||||
```
|
||||
|
||||
By aliasing **http** directly to the command inside the virtual environment, you can run it even when the virtual environment is not active. You can put the **alias** command in **.bash_profile** or **.bashrc** so you can upgrade HTTPie with the command:
|
||||
|
||||
|
||||
```
|
||||
`$ ~/.virtualenvs/httpie/bin/pip install -U pip`
|
||||
```
|
||||
|
||||
### Query a website with HTTPie
|
||||
|
||||
HTTPie can simplify querying and testing an API. One option for running it, **-b** (also known as **\--body**), was used above. Without it, HTTPie will print the entire response, including the headers, by default:
|
||||
|
||||
|
||||
```
|
||||
$ http GET <https://httpbin.org/get>
|
||||
HTTP/1.1 200 OK
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Connection: keep-alive
|
||||
Content-Encoding: gzip
|
||||
Content-Length: 177
|
||||
Content-Type: application/json
|
||||
Date: Fri, 09 Aug 2019 20:19:47 GMT
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
|
||||
{
|
||||
"args": {},
|
||||
"headers": {
|
||||
"Accept": "*/*",
|
||||
"Accept-Encoding": "gzip, deflate",
|
||||
"Host": "httpbin.org",
|
||||
"User-Agent": "HTTPie/1.0.2"
|
||||
},
|
||||
"origin": "104.220.242.210, 104.220.242.210",
|
||||
"url": "<https://httpbin.org/get>"
|
||||
}
|
||||
```
|
||||
|
||||
This is crucial when debugging an API service because a lot of information is sent in the headers. For example, it is often important to see which cookies are being sent. Httpbin.org provides options to set cookies (for testing purposes) through the URL path. The following sets a cookie titled **opensource** to the value **awesome**:
|
||||
|
||||
|
||||
```
|
||||
$ http GET <https://httpbin.org/cookies/set/opensource/awesome>
|
||||
HTTP/1.1 302 FOUND
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Connection: keep-alive
|
||||
Content-Length: 223
|
||||
Content-Type: text/html; charset=utf-8
|
||||
Date: Fri, 09 Aug 2019 20:22:39 GMT
|
||||
Location: /cookies
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
Set-Cookie: opensource=awesome; Path=/
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|
||||
<title>Redirecting...</title>
|
||||
<h1>Redirecting...</h1>
|
||||
<p>You should be redirected automatically to target URL:
|
||||
<a href="/cookies">/cookies</a>. If not click the link.
|
||||
```
|
||||
|
||||
Notice the **Set-Cookie: opensource=awesome; Path=/** header. This shows the cookie you expected to be set is set correctly and with a **/** path. Also notice that, even though you got a **302** redirect, **http** did not follow it. If you want to follow redirects, you need to ask for it explicitly with the **\--follow** flag:
|
||||
|
||||
|
||||
```
|
||||
$ http --follow GET <https://httpbin.org/cookies/set/opensource/awesome>
|
||||
HTTP/1.1 200 OK
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Connection: keep-alive
|
||||
Content-Encoding: gzip
|
||||
Content-Length: 66
|
||||
Content-Type: application/json
|
||||
Date: Sat, 10 Aug 2019 01:33:34 GMT
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
|
||||
{
|
||||
"cookies": {
|
||||
"opensource": "awesome"
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
But now you cannot see the original **Set-Cookie** header. In order to see intermediate replies, you need to use **\--all**:
|
||||
|
||||
|
||||
```
|
||||
$ http --headers --all --follow \
|
||||
GET <https://httpbin.org/cookies/set/opensource/awesome>
|
||||
HTTP/1.1 302 FOUND
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Content-Type: text/html; charset=utf-8
|
||||
Date: Sat, 10 Aug 2019 01:38:40 GMT
|
||||
Location: /cookies
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
Set-Cookie: opensource=awesome; Path=/
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
Content-Length: 223
|
||||
Connection: keep-alive
|
||||
|
||||
HTTP/1.1 200 OK
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Content-Encoding: gzip
|
||||
Content-Type: application/json
|
||||
Date: Sat, 10 Aug 2019 01:38:41 GMT
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
Content-Length: 66
|
||||
Connection: keep-alive
|
||||
```
|
||||
|
||||
Printing the body is uninteresting because you are mostly interested in the cookies. If you want to see the headers from the intermediate request but the body from the final request, you can do that with:
|
||||
|
||||
|
||||
```
|
||||
$ http --print hb --history-print h --all --follow \
|
||||
GET <https://httpbin.org/cookies/set/opensource/awesome>
|
||||
HTTP/1.1 302 FOUND
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Content-Type: text/html; charset=utf-8
|
||||
Date: Sat, 10 Aug 2019 01:40:56 GMT
|
||||
Location: /cookies
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
Set-Cookie: opensource=awesome; Path=/
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
Content-Length: 223
|
||||
Connection: keep-alive
|
||||
|
||||
HTTP/1.1 200 OK
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Content-Encoding: gzip
|
||||
Content-Type: application/json
|
||||
Date: Sat, 10 Aug 2019 01:40:56 GMT
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
Content-Length: 66
|
||||
Connection: keep-alive
|
||||
|
||||
{
|
||||
"cookies": {
|
||||
"opensource": "awesome"
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
You can control exactly what is being printed with **\--print** and override what is printed for intermediate requests with **\--history-print**.
|
||||
|
||||
### Download binary files with HTTPie
|
||||
|
||||
Sometimes the body is non-textual and needs to be sent to a file that can be opened by a different application:
|
||||
|
||||
|
||||
```
|
||||
$ http GET <https://httpbin.org/image/jpeg>
|
||||
HTTP/1.1 200 OK
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Connection: keep-alive
|
||||
Content-Length: 35588
|
||||
Content-Type: image/jpeg
|
||||
Date: Fri, 09 Aug 2019 20:25:49 GMT
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
|
||||
+-----------------------------------------+
|
||||
| NOTE: binary data not shown in terminal |
|
||||
+-----------------------------------------+
|
||||
```
|
||||
|
||||
To get the right image, you need to save it to a file:
|
||||
|
||||
|
||||
```
|
||||
$ http --download GET <https://httpbin.org/image/jpeg>
|
||||
HTTP/1.1 200 OK
|
||||
Access-Control-Allow-Credentials: true
|
||||
Access-Control-Allow-Origin: *
|
||||
Connection: keep-alive
|
||||
Content-Length: 35588
|
||||
Content-Type: image/jpeg
|
||||
Date: Fri, 09 Aug 2019 20:28:13 GMT
|
||||
Referrer-Policy: no-referrer-when-downgrade
|
||||
Server: nginx
|
||||
X-Content-Type-Options: nosniff
|
||||
X-Frame-Options: DENY
|
||||
X-XSS-Protection: 1; mode=block
|
||||
|
||||
Downloading 34.75 kB to "jpeg.jpe"
|
||||
Done. 34.75 kB in 0.00068s (50.05 MB/s)
|
||||
```
|
||||
|
||||
Try it! The picture is adorable.
|
||||
|
||||
### Sending custom requests with HTTPie
|
||||
|
||||
You can also send specific headers. This is useful for custom web APIs that require a non-standard header:
|
||||
|
||||
|
||||
```
|
||||
$ http GET <https://httpbin.org/headers> X-Open-Source-Com:Awesome
|
||||
{
|
||||
"headers": {
|
||||
"Accept": "*/*",
|
||||
"Accept-Encoding": "gzip, deflate",
|
||||
"Host": "httpbin.org",
|
||||
"User-Agent": "HTTPie/1.0.2",
|
||||
"X-Open-Source-Com": "Awesome"
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Finally, if you want to send JSON fields (although it is possible to specify exact content), for many less-nested inputs, you can use a shortcut:
|
||||
|
||||
|
||||
```
|
||||
$ http --body PUT <https://httpbin.org/anything> open-source=awesome author=moshez
|
||||
{
|
||||
"args": {},
|
||||
"data": "{\"open-source\": \"awesome\", \"author\": \"moshez\"}",
|
||||
"files": {},
|
||||
"form": {},
|
||||
"headers": {
|
||||
"Accept": "application/json, */*",
|
||||
"Accept-Encoding": "gzip, deflate",
|
||||
"Content-Length": "46",
|
||||
"Content-Type": "application/json",
|
||||
"Host": "httpbin.org",
|
||||
"User-Agent": "HTTPie/1.0.2"
|
||||
},
|
||||
"json": {
|
||||
"author": "moshez",
|
||||
"open-source": "awesome"
|
||||
},
|
||||
"method": "PUT",
|
||||
"origin": "73.162.254.113, 73.162.254.113",
|
||||
"url": "<https://httpbin.org/anything>"
|
||||
}
|
||||
```
|
||||
|
||||
The next time you are debugging a web API, whether your own or someone else's, put down your cURL and reach for HTTPie, the command-line client for web APIs.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/getting-started-httpie
|
||||
|
||||
作者：[Moshe Zadka][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/moshezhttps://opensource.com/users/mkalindepauleduhttps://opensource.com/users/jamesf
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/pie-raspberry-bake-make-food.png?itok=QRV_R8Fa (Raspberry pie with slice missing)
|
||||
[2]: https://httpie.org/
|
||||
[3]: https://github.com/postmanlabs/httpbin
|
||||
[4]: https://en.wikipedia.org/wiki/Wget
|
||||
[5]: https://en.wikipedia.org/wiki/CURL
|
||||
[6]: https://opensource.com/article/19/6/virtual-environments-python-macos
|
||||
138
sources/tech/20190829 Variables in PowerShell.md
Normal file
138
sources/tech/20190829 Variables in PowerShell.md
Normal file
@ -0,0 +1,138 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Variables in PowerShell)
|
||||
[#]: via: (https://opensource.com/article/19/8/variables-powershell)
|
||||
[#]: author: (Seth Kenlon https://opensource.com/users/seth)
|
||||
|
||||
Variables in PowerShell
|
||||
======
|
||||
In our miniseries Variables in Shells, learn how to handle local
|
||||
variables in PowerShell.
|
||||
![Shells in a competition][1]
|
||||
|
||||
In computer science (and casual computing), a variable is a location in memory that holds arbitrary information for later use. In other words, it’s a temporary storage container for you to put data into and get data out of. In the Bash shell, that data can be a word (a _string_, in computer lingo) or a number (an _integer_).
|
||||
|
||||
You may have never (knowingly) used a variable before on your computer, but you probably have used a variable in another area of your life. When you say things like "give me that" or "look at this," you’re using grammatical variables (you think of them as _pronouns_). The meaning of "this" and "that" depends on whatever you’re picturing in your mind, or whatever you’re pointing to as an indicator for your audience to know what you’re referring to. When you do math, you use variables to stand in for unknown values, even though you probably don’t call them variables.
|
||||
|
||||
This article addresses variables in [PowerShell][2], which runs on Windows, Linux, or Mac. Users of the open source [Bash][3] shell should refer to my article about variables in the Bash shell instead (although you can run PowerShell on Linux, and it is open source, so you can still follow along with this article).
|
||||
|
||||
**Note:** The examples in this article are from a PowerShell session running on the open source operating system Linux, so if you’re on Windows or Mac the file paths will differ. However, Windows converts **/** to **\** automatically, and all examples work across all platforms, provided that you substitute obvious differences (for instance, it is statistically unlikely that your username is **seth**).
|
||||
|
||||
### What are variables for?
|
||||
|
||||
Whether you need variables in PowerShell depends on what you do in a terminal. For some users, variables are an essential means of managing data, while for others they’re minor and temporary conveniences, or for some, they may as well not exist.
|
||||
|
||||
Ultimately, variables are a tool. You can use them when you find a use for them, or leave them alone in the comfort of knowing they’re managed by your OS. Knowledge is power, though, and understanding how variables work in Bash can lead you to all kinds of unexpected creative problem-solving.
|
||||
|
||||
### Set a variable
|
||||
|
||||
You don’t need special permissions to create a variable. They’re free to create, free to use, and generally harmless. In PowerShell, you create a variable by defining a variable name and then setting its value with the **Set-Variable** command. The example below creates a new variable called **FOO** and sets its value to the string **$HOME/Documents**:
|
||||
|
||||
|
||||
```
|
||||
`PS> Set-Variable -Name FOO -Value "$HOME/Documents"`
|
||||
```
|
||||
|
||||
Success is eerily silent, so you may not feel confident that your variable got set. You can see the results for yourself with the **Get-Variable** (**gv** for short) command. To ensure that the variable is read exactly as you defined it, you can also wrap it in quotes. Doing so preserves any special characters that might appear in the variable; in this example, that doesn’t apply, but it’s still a good habit to form:
|
||||
|
||||
|
||||
```
|
||||
PS> Get-Variable "FOO" -valueOnly
|
||||
/home/seth/Documents
|
||||
```
|
||||
|
||||
Notice that the contents of **FOO** aren’t exactly what you set. The literal string you set for the variable was **$HOME/Documents**, but now it’s showing up as **/home/seth/Documents**. This happened because you can nest variables. The **$HOME** variable points to the current user’s home directory, whether it’s in **C:\Users** on Windows, **/home** on Linux, or **/Users** on Mac. Since **$HOME** was embedded in **FOO**, that variable gets _expanded_ when recalled. Using default variables in this way helps you write portable scripts that operate across platforms.
|
||||
|
||||
Variables usually are meant to convey information from one system to another. In this simple example, your variable is not very useful, but it can still communicate information. For instance, because the content of the **FOO** variable is a [file path][4], you can use **FOO** as a shortcut to the directory its value references.
|
||||
|
||||
To reference the variable **FOO**’s _contents_ and not the variable itself, prepend the variable with a dollar sign (**$**):
|
||||
|
||||
|
||||
```
|
||||
PS> pwd
|
||||
/home/seth
|
||||
PS> cd "$FOO"
|
||||
PS> pwd
|
||||
/home/seth/Documents
|
||||
```
|
||||
|
||||
### Clear a variable
|
||||
|
||||
You can remove a variable with the **Remove-Variable** command:
|
||||
|
||||
|
||||
```
|
||||
PS> Remove-Variable -Name "FOO"
|
||||
PS> gv "FOO"
|
||||
gv : Cannot find a variable with the name 'FOO'.
|
||||
[...]
|
||||
```
|
||||
|
||||
In practice, removing a variable is not usually necessary. Variables are relatively "cheap," so you can create them and forget them when you don’t need them anymore. However, there may be times you want to ensure a variable is empty to avoid conveying unwanted information to another process that might read that variable.
|
||||
|
||||
### Create a new variable with collision protection
|
||||
|
||||
Sometimes, you may have reason to believe a variable was already set by you or some other process. If you would rather not override it, you can either use **New-Variable**, which is designed to fail if a variable with the same name already exists, or you can use a conditional statement to check for a variable first:
|
||||
|
||||
|
||||
```
|
||||
PS> New-Variable -Name FOO -Value "example"
|
||||
New-Variable : A variable with name 'FOO' already exists.
|
||||
```
|
||||
|
||||
**Note:** In these examples, assume that **FOO** is set to **/home/seth/Documents**.
|
||||
|
||||
Alternately, you can construct a simple **if** statement to check for an existing variable:
|
||||
|
||||
|
||||
```
|
||||
PS> if ( $FOO )
|
||||
>> { gv FOO } else
|
||||
>> { Set-Variable -Name "FOO" -Value "quux" }
|
||||
```
|
||||
|
||||
### Add to a variable
|
||||
|
||||
Instead of overwriting a variable, you can add to an existing one. In PowerShell, variables have diverse types, including string, integer, and array. When choosing to create a variable with, essentially, more than one value, you must decide whether you need a [character-delimited string][5] or an [array][6]. You may not care one way or the other, but the application receiving the variable’s data may expect one or the other, so make your choice based on your target.
|
||||
|
||||
To append data to a string variable, use the **=+** syntax:
|
||||
|
||||
|
||||
```
|
||||
PS> gv FOO
|
||||
foo
|
||||
PS> $FOO =+ "$FOO,bar"
|
||||
PS> gv FOO
|
||||
foo,bar
|
||||
PS> $FOO.getType().Name
|
||||
String
|
||||
```
|
||||
|
||||
Arrays are special types of variables in PowerShell and require an ArrayList object. That’s out of scope for this article, as it requires delving deeper into PowerShell’s .NET internals.
|
||||
|
||||
### Go global with environment variables
|
||||
|
||||
So far the variables created in this article have been _local_, meaning that they apply only to the PowerShell session you create them in. To create variables that are accessible to other processes, you can create environment variables, which will be covered in a future article.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/variables-powershell
|
||||
|
||||
作者：[Seth Kenlon][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/seth
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/shelloff.png?itok=L8pjHXjW (Shells in a competition)
|
||||
[2]: https://en.wikipedia.org/wiki/PowerShell
|
||||
[3]: https://www.gnu.org/software/bash/
|
||||
[4]: https://opensource.com/article/19/8/understanding-file-paths-linux
|
||||
[5]: https://en.wikipedia.org/wiki/Delimiter
|
||||
[6]: https://en.wikipedia.org/wiki/Array_data_structure
|
||||
202
sources/tech/20190829 What is an Object in Java.md
Normal file
202
sources/tech/20190829 What is an Object in Java.md
Normal file
@ -0,0 +1,202 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (What is an Object in Java?)
|
||||
[#]: via: (https://opensource.com/article/19/8/what-object-java)
|
||||
[#]: author: (Chris Hermansen https://opensource.com/users/clhermansenhttps://opensource.com/users/mdowdenhttps://opensource.com/users/sethhttps://opensource.com/users/drmjghttps://opensource.com/users/jamesfhttps://opensource.com/users/clhermansen)
|
||||
|
||||
What is an Object in Java?
|
||||
======
|
||||
Java's approach to object-oriented programming is the basis for almost
|
||||
everything in the language. Here's what you need to know.
|
||||
![Coffee beans and a cup of coffee][1]
|
||||
|
||||
Java is an object-oriented programming language, which views the world as a collection of objects that have both _properties_ and _behavior_. Java's version of object-orientedness is pretty straightforward, and it's the basis for almost everything in the language. Because it's so essential to Java, I'll explain a bit about what's under the covers to help anyone new to the language.
|
||||
|
||||
### Inheritance
|
||||
|
||||
In general, all [Cartesian geometric objects][2], like circles, squares, triangles, lines, and points, have basic properties, like location and extension. Objects with zero extension, like points, usually don't have anything more than that. Objects like lines have more—e.g., the start and endpoint of a line segment or two points along a line (if it's a "true line"). Objects like squares or triangles have still more—the corner points, for example—whereas circles may have a center and radius.
|
||||
|
||||
We can see there is a simple hierarchy at work here: The general geometric object can be _extended_ into specific geometric objects, like points, lines, squares, etc. Each specific geometric object _inherits_ the basic geometric properties of location and extension and adds its own properties.
|
||||
|
||||
This is an example of _single inheritance_. Java's original object-oriented model allowed only single inheritance, where objects cannot belong to more than one inheritance hierarchy. This design decision comes out of the kinds of ambiguities programmers found themselves facing in [complex multiple-inheritance scenarios][3], typically in cases where "interesting design decisions" led to several possible implementations of the function **foo()** as defined (and re-defined) in the hierarchy.
|
||||
|
||||
Since Java 8, there has been a limited multiple inheritance structure in place that requires specific actions on behalf of the programmer to ensure there are no ambiguities.
|
||||
|
||||
### Strong and static typing
|
||||
|
||||
Java is _strongly_ and _statically_ typed. What does this mean?
|
||||
|
||||
A _statically_ typed language is one where the type of a variable is known at compile time. In this situation, it is not possible to assign a value of type B to a variable whose declared type is A, unless there is a conversion mechanism to turn a value of type B into a value of type A. An example of this type of conversion is turning an integer value, like 1, 2, or 42, into a floating-point value, like 1.0, 2.0, or 42.0.
|
||||
|
||||
A _strongly_ typed language is one where very few (or perhaps no) type conversions are applied automatically. For example, whereas a strongly typed language might permit automatic conversion of _integer_ to _real_, it will never permit automatic conversion of _real_ to _integer_ since that conversion requires either rounding or truncation in the general case.
|
||||
|
||||
### Primitive types, classes, and objects
|
||||
|
||||
Java provides a number of primitive types: _byte_ (an eight-bit signed integer); _short_ (a 16-bit signed integer); _int_ (a 32-bit signed integer); _long_ (a 64-bit signed integer); _float_ (a single precision 32-bit IEEE floating-point number); _double_ (a double precision 64-bit IEEE floating-point number); _boolean_ (true or false); and _char_ (a 16-bit Unicode character).
|
||||
|
||||
Beyond those primitive types, Java allows the programmer to create new types using _class declarations_. Class declarations are used to define object templates, including their properties and behavior. Once a class is declared, _instances_ of that class can generally be created using the **new** keyword. These instances correspond directly to the "objects" we have been discussing. Java comes with a library of useful class definitions, including some simple basic classes such as _String_, which is used to hold a sequence of characters like "Hello, world."
|
||||
|
||||
Let's define a simple message class that contains the name of the sender as well as the message text:
|
||||
|
||||
|
||||
```
|
||||
class Message {
|
||||
[String][4] sender;
|
||||
[String][4] text;
|
||||
public Message([String][4] sender, [String][4] text) {
|
||||
this.sender = sender;
|
||||
this.text = text;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
There are several important things to note in this class declaration:
|
||||
|
||||
1. The class is (by convention) always declared with a leading capital letter.
|
||||
2. The **Message** class contains two properties (or fields):
|
||||
– a String field called **sender**
|
||||
– a String field called **text**
|
||||
Properties or fields are (by convention) always declared with a leading lower-case letter.
|
||||
3. There is some kind of thing that starts with **public Message**.
|
||||
– It is a _method_ (methods define the behavior of an object).
|
||||
– It is used to _construct_ instances of the class **Message**.
|
||||
– Constructor methods always take the same name as the class and are understood to return an instance of the class once it's constructed.
|
||||
– Other methods are (by convention) always declared with a leading lower-case letter.
|
||||
– This constructor is "public," meaning any caller can access it.
|
||||
4. As part of the construction process, some lines start with **this**.
|
||||
– **this** refers to the present instance of the class.
|
||||
– Thus **this.sender** refers to the sender property of the object.
|
||||
– Whereas plain **sender** refers to the parameter of the **Message** constructor method.
|
||||
– Therefore, these two lines are copying the values provided in the call to the constructor into the fields of the object itself.
|
||||
|
||||
|
||||
|
||||
So we have the **Method** class definition. How do we use it? The following code excerpt shows one possible way:
|
||||
|
||||
|
||||
```
|
||||
`Message message = new Message("system", "I/O error");`
|
||||
```
|
||||
|
||||
Here we see:
|
||||
|
||||
1. The declaration of the variable **message** of type **Message**
|
||||
2. The creation of a new instance of the **Message** class with **sender** set to "system" and **text** set to "I/O error"
|
||||
3. The assignment of that new instance of **Message** to the variable **message**
|
||||
4. If later in the code, the variable **message** is assigned a different value (another instance of **Message**) and no other variable was created that referred to this instance of **Message**, then this instance is no longer used by anything and can be garbage-collected.
|
||||
|
||||
|
||||
|
||||
The key thing happening here is that we are creating an object of type **Message** and keeping a reference to that object in the variable **message**.
|
||||
|
||||
We can now use that message; for instance, we can print the values in the **sender** and **text** properties, like this:
|
||||
|
||||
|
||||
```
|
||||
[System][5].out.println("message sender = " + message.sender);
|
||||
[System][5].out.println("message text = " + message.text);
|
||||
```
|
||||
|
||||
This is a very simple and unsophisticated class definition. We can modify this class definition in a number of ways:
|
||||
|
||||
1. We can make the implementation details of properties invisible to callers by using the keyword **private** in front of the declarations, allowing us to change the implementation without affecting callers.
|
||||
2. If we choose to conceal properties in the class, we would then typically define procedures for _getting_ and _setting_ those properties; by convention in Java these would be defined as:
|
||||
– **public String getSender()**
|
||||
– **public String getText()**
|
||||
– **public void setSender(String sender)**
|
||||
– **public void setText(String text)**
|
||||
3. In some cases, we may wish to have "read-only" properties; in those cases, we would not define setters for such properties.
|
||||
4. We can make the constructor of the class invisible to callers by using the **private** keyword instead of **public**. We might wish to do this when we have another class whose responsibility is creating and managing a pool of messages (possibly executing in another process or even on another system).
|
||||
|
||||
|
||||
|
||||
Now, suppose we want a kind of message that records when it was generated. We could declare it this like:
|
||||
|
||||
|
||||
```
|
||||
class TimedMessage extends Message {
|
||||
long creationTime;
|
||||
public TimedMessage([String][4] sender, [String][4] text) {
|
||||
super(sender, text);
|
||||
this.creationTime = [System][5].currentTimeMillis();
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Here we see some new things:
|
||||
|
||||
1. **TimedMessage** is _extending_ the **Message** class—that is, **TimedMessage** is inheriting properties and behavior from **Message**.
|
||||
2. The constructor calls the constructor in its parent, or _superclass_, with the values of **sender** and **text** passed in, as **super(sender, text)**, in order to make sure its inherited properties are properly initialized.
|
||||
3. **TimedMessage** adds a new property, **creationTime**, and the constructor sets it to be the current system time in milliseconds.
|
||||
4. Time in milliseconds in Java is kept as a long (64-bit) value (0 is 1 January, 1970 00:00:00 UTC).
|
||||
5. As a bit of an aside, the name **creationTime** suggests it should be a read-only property, which also suggests that the other properties be read-only; that is, **TimedMessage** instances should probably not be reused nor have their properties altered.
|
||||
|
||||
|
||||
|
||||
### The Object class
|
||||
|
||||
"The Object class" sounds like a kind of contradiction in terms, doesn't it? But notice that the first class we defined, **Message**, did not _appear_ to extend anything—but it _actually_ did. All classes that don't specifically extend another class have the class **Object** as their immediate and only parent; therefore, all classes have the **Object** class as their ultimate superclass.
|
||||
|
||||
You can [learn more about the **Object** class][6] in Java's docs. Let's (briefly) review some interesting details:
|
||||
|
||||
1. **Object** has the constructor **Object()**, that is, with no parameters.
|
||||
2. **Object** provides some useful methods to all of its subclasses, including:
|
||||
– **clone()**, which creates and returns a copy of the instance at hand
|
||||
– **equals(Object anotherObject)**, which determines whether **anotherObject** is equal to the instance of **Object** at hand
|
||||
– **finalize()**, which is used to garbage-collect the instance at hand when it is no longer used (see above)
|
||||
– **getClass()**, which returns the class used to declare the instance at hand
|
||||
— The value returned by this is an instance of the [**Class** class][7], which permits learning about the declaring class at runtime—a process referred to _introspection_.
|
||||
3. **hashCode()** is an integer value that gives a nearly unique value for the instance at hand.
|
||||
– If the hash codes of two distinct instances are equal, then they may be equal; a detailed comparison of the properties (and perhaps methods) is necessary to determine complete equality;
|
||||
– If the hash codes are not equal, then the instances are also not equal.
|
||||
– Therefore, hash codes can speed up equality tests.
|
||||
– A hash code can also be used to create a [**HashMap**][8] (a map is an associative array or dictionary that uses the hash code to speed up lookups) and a [**HashSet**][9] (a set is a collection of objects; the programmer can test whether an instance is in a set or not; hash codes are used to speed up the test).
|
||||
4. **notify()**, **notifyAll()**, **wait()**, **wait(long timeout)**, and **wait(long timeout, int nanos)** communicate between collaborating instances executing on separate threads.
|
||||
5. **toString()** produces a printable version of the instance.
|
||||
|
||||
|
||||
|
||||
### Concluding thoughts
|
||||
|
||||
We've touched on some important aspects of object-oriented programming, Java-style. There are six important, related topics that will be covered in future articles:
|
||||
|
||||
* Namespaces and packages
|
||||
* Overriding methods in subclasses—for instance, the String class has its own specific **hashCode()** method that recognizes its meaning as an array of characters; this is accomplished by overriding the **hashCode()** method inherited from Object
|
||||
* Interfaces, which permit describing behavior that must be provided by a class that implements the interface; instances of classes that implement a given interface can be referred to by that interface when the only thing of interest is that specific behavior
|
||||
* Arrays of primitives or classes and collections of classes (such as lists, maps, and sets)
|
||||
* Overloading of methods—where several methods with the same name and similar behavior have different parameters
|
||||
* Using libraries that don't come with the Java distribution
|
||||
|
||||
|
||||
|
||||
Is there anything you would like to read next? Let us know in the comments and stay tuned!
|
||||
|
||||
Michael Dowden takes a look at four Java web frameworks built for scalability.
|
||||
|
||||
Optimizing your Java code requires an understanding of how the different elements in Java interact...
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/what-object-java
|
||||
|
||||
作者：[Chris Hermansen][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/clhermansenhttps://opensource.com/users/mdowdenhttps://opensource.com/users/sethhttps://opensource.com/users/drmjghttps://opensource.com/users/jamesfhttps://opensource.com/users/clhermansen
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/java-coffee-mug.jpg?itok=Bj6rQo8r (Coffee beans and a cup of coffee)
|
||||
[2]: https://en.wikipedia.org/wiki/Analytic_geometry
|
||||
[3]: https://en.wikipedia.org/wiki/Multiple_inheritance
|
||||
[4]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+string
|
||||
[5]: http://www.google.com/search?hl=en&q=allinurl%3Adocs.oracle.com+javase+docs+api+system
|
||||
[6]: https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html
|
||||
[7]: https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html
|
||||
[8]: https://docs.oracle.com/javase/8/docs/api/java/util/HashMap.html
|
||||
[9]: https://docs.oracle.com/javase/8/docs/api/java/util/HashSet.html
|
||||
@ -0,0 +1,87 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Change your Linux terminal color theme)
|
||||
[#]: via: (https://opensource.com/article/19/8/add-color-linux-terminal)
|
||||
[#]: author: (Seth Kenlon https://opensource.com/users/seth)
|
||||
|
||||
Change your Linux terminal color theme
|
||||
======
|
||||
Your terminal has plenty of options that allow you to theme what you
|
||||
see.
|
||||
![Terminal command prompt on orange background][1]
|
||||
|
||||
If you spend most of your day staring into a terminal, it's only natural that you want it to look pleasing. Beauty is in the eye of the beholder, and terminals have come a long way since the days of CRT serial consoles. So, the chances are good that your software terminal window has plenty of options to theme what you see—however you define beauty.
|
||||
|
||||
### Settings
|
||||
|
||||
Most popular software terminal applications, including GNOME, KDE, and Xfce, ship with the option to change their color theme. Adjusting your theme is as easy as adjusting application preferences. Fedora, RHEL, and Ubuntu ship with GNOME by default, so this article uses that terminal as its example, but the process is similar for Konsole, Xfce terminal, and many others.
|
||||
|
||||
First, navigate to the application's Preferences or Settings panel. In GNOME terminal, you reach it through the Application menu along the top of the screen or in the right corner of the window.
|
||||
|
||||
In Preferences, click the plus symbol (+) next to Profiles to create a new theme profile. In your new profile, click the Colors tab.
|
||||
|
||||
![GNOME Terminal preferences][2]
|
||||
|
||||
In the Colors tab, deselect the Use Colors From System Theme option so that the rest of the window will become active. As a starting point, you can select a built-in color scheme. These include light themes, with bright backgrounds and dark foreground text, as well as dark themes, with dark backgrounds and light foreground text.
|
||||
|
||||
The Default Color swatches define both the foreground and background colors when no other setting (such as settings from the dircolors command) overrides them. The Palette sets the colors defined by the dircolors command. These colors are used by your terminal, in the form of the LS_COLORS environment variable, to add color to the output of the [ls][3] command. If none of them appeal to you, change them on this screen.
|
||||
|
||||
When you're happy with your theme, close the Preferences window.
|
||||
|
||||
To change your terminal to your new profile, click on the Application menu, and select Profile. Choose your new profile and enjoy your custom theme.
|
||||
|
||||
![GNOME Terminal profile selection][4]
|
||||
|
||||
### Command options
|
||||
|
||||
If your terminal doesn't have a fancy settings window, it may still provide options for colors in your launch command. The xterm and rxvt terminals (the old one and the Unicode-enabled variant, sometimes called urxvt or rxvt-unicode) provide such options, so you can still theme your terminal emulator—even without desktop environments and big GUI frameworks.
|
||||
|
||||
The two obvious options are the foreground and background colors, defined by **-fg** and **-bg**, respectively. The argument for each option is the color _name_ rather than its ANSI number. For example:
|
||||
|
||||
|
||||
```
|
||||
`$ urxvt -bg black -fg green`
|
||||
```
|
||||
|
||||
These settings set the default foreground and background. Should any other rule govern the color of a specific file or device type, those colors are used. See the [dircolors][5] command for information on how to set those.
|
||||
|
||||
You can also set the color of the text cursor (not the mouse cursor) with **-cr**:
|
||||
|
||||
|
||||
```
|
||||
`$ urxvt -bg black -fg green -cr teal`
|
||||
```
|
||||
|
||||
![Setting color in urxvt][6]
|
||||
|
||||
Your terminal emulator may have more options, like a border color (**-bd** in rxvt), cursor blink (**-bc** and **+bc** in urxvt), and even background transparency. Refer to your terminal's man page to find out what cool features are available.
|
||||
|
||||
To launch your terminal with your choice of colors, you can add the options either to the command or the menu you use to launch the terminal (such as your Fluxbox menu file, a **.desktop** file in **$HOME/.local/share/applications**, or similar). Alternatively, you can use the [xrdb][7] tool to manage X-related resources (but that's out of scope for this article).
|
||||
|
||||
### Home is where the customization is
|
||||
|
||||
Customizing your Linux machine doesn't mean you have to learn how to program. You can and should make small but meaningful changes to make your digital home feel that much more comfortable. And there's no better place to start than the terminal!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/8/add-color-linux-terminal
|
||||
|
||||
作者：[Seth Kenlon][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/seth
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/terminal_command_linux_desktop_code.jpg?itok=p5sQ6ODE (Terminal command prompt on orange background)
|
||||
[2]: https://opensource.com/sites/default/files/uploads/gnome-terminal-preferences.jpg (GNOME Terminal preferences)
|
||||
[3]: https://opensource.com/article/19/7/master-ls-command
|
||||
[4]: https://opensource.com/sites/default/files/uploads/gnome-terminal-profile-select.jpg (GNOME Terminal profile selection)
|
||||
[5]: http://man7.org/linux/man-pages/man1/dircolors.1.html
|
||||
[6]: https://opensource.com/sites/default/files/uploads/urxvt-color.jpg (Setting color in urxvt)
|
||||
[7]: https://www.x.org/releases/X11R7.7/doc/man/man1/xrdb.1.xhtml
|
||||
@ -0,0 +1,110 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Command line quick tips: Using pipes to connect tools)
|
||||
[#]: via: (https://fedoramagazine.org/command-line-quick-tips-using-pipes-to-connect-tools/)
|
||||
[#]: author: (Paul W. Frields https://fedoramagazine.org/author/pfrields/)
|
||||
|
||||
Command line quick tips: Using pipes to connect tools
|
||||
======
|
||||
|
||||
![][1]
|
||||
|
||||
One of the most powerful concepts of Linux is carried on from its predecessor, UNIX. Your Fedora system has a bunch of useful, single-purpose utilities available for all sorts of simple operations. Like building blocks, you can attach them in creative and complex ways. _Pipes_ are key to this concept.
|
||||
|
||||
Before you hear about pipes, though, it’s helpful to know the basic concept of input and output. Many utilities in your Fedora system can operate against files. But they can often take input not stored on a disk. You can think of input flowing freely into a process such as a utility as its _standard input_ (also sometimes called _stdin_).
|
||||
|
||||
Similarly, a tool or process can display information to the screen by default. This is often because its default output is connected to the terminal. You can think of the free-flowing output of a process as its _standard output_ (or _stdout_ — go figure!).
|
||||
|
||||
### Examples of standard input and output
|
||||
|
||||
Often when you run a tool, it outputs to the terminal. Take for instance this simple sequence command using the _seq_ tool:
|
||||
|
||||
```
|
||||
$ seq 1 6
|
||||
1
|
||||
2
|
||||
3
|
||||
4
|
||||
5
|
||||
6
|
||||
```
|
||||
|
||||
The output, which is simply to count integers up from 1 to 6, one number per line, comes to the screen. But you could also send it to a file using the **>** character. The shell interpreter uses this character to mean “redirect _standard output_ to a file whose name follows.” So as you can guess, this command puts the output into a file called _six.txt:_
|
||||
|
||||
```
|
||||
$ seq 1 6 > six.txt
|
||||
```
|
||||
|
||||
Notice nothing comes to the screen. You’ve sent the ouptut into a file instead. If you run the command _cat six.txt_ you can verify that.
|
||||
|
||||
You probably remember the simple use of the _grep_ command [from a previous article][2]. You could ask _grep_ to search for a pattern in a file by simply declaring the file name. But that’s simply a convenience feature in _grep_. Technically it’s built to take _standard input_, and search that.
|
||||
|
||||
The shell uses the **<** character similarly to mean “redirect _standard input_ from a file whose name follows.” So you could just as well search for the number **4** in the file _six.txt_ this way:
|
||||
|
||||
```
|
||||
$ grep 4 < six.txt
|
||||
4
|
||||
```
|
||||
|
||||
Of course the output here is, by default, the content of any line with a match. So _grep_ finds the digit **4** in the file and outputs that line to _standard output_.
|
||||
|
||||
### Introducing pipes
|
||||
|
||||
Now imagine: what if you took the standard output of one tool, and instead of sending it to the terminal, you sent it into another tool’s standard input? This is the essence of the pipe.
|
||||
|
||||
Your shell uses the vertical bar character **|** to represent a pipe between two commands. You can find it on most keyboard above the backslash **\** character. It’s used like this:
|
||||
|
||||
```
|
||||
$ command1 | command2
|
||||
```
|
||||
|
||||
For most simple utilities, you wouldn’t use an output filename option on _command1_, nor an input file option on _command2_. (You might use other options, though.) Instead of using files, you’re sending the output of _command1_ directly into _command2_. You can use as many pipes in a row as needed, creating complex pipelines of several commands in a row.
|
||||
|
||||
This (relatively useless) example combines the commands above:
|
||||
|
||||
```
|
||||
$ seq 1 6 | grep 4
|
||||
4
|
||||
```
|
||||
|
||||
What happened here? The _seq_ command outputs the integers 1 through 6, one line at a time. The _grep_ command processes that output line by line, searching for a match on the digit **4**, and outputs any matching line.
|
||||
|
||||
Here’s a slightly more useful example. Let’s say you want to find out if TCP port 22, the _ssh_ port, is open on your system. You could find this out using the _ss_ command* by looking through its copious output. Or you could figure out its filter language and use that. Or you could use pipes. For example, pipe it through _grep_ looking for the _ssh_ port label:
|
||||
|
||||
```
|
||||
$ ss -tl | grep ssh
|
||||
LISTEN 0 128 0.0.0.0:ssh 0.0.0.0:*
|
||||
LISTEN 0 128 [::]:ssh [::]:*
|
||||
```
|
||||
|
||||
_* Those readers familiar with the venerable_ netstat _command may note it is mostly obsolete, as stated in its [man page][3]._
|
||||
|
||||
That’s a lot easier than reading through many lines of output. And of course, you can combine redirectors and pipes, for instance:
|
||||
|
||||
```
|
||||
$ ss -tl | grep ssh > ssh-listening.txt
|
||||
```
|
||||
|
||||
This is barely scratching the surface of pipes. Let your imagination run wild. Have fun piping!
|
||||
|
||||
* * *
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/command-line-quick-tips-using-pipes-to-connect-tools/
|
||||
|
||||
作者：[Paul W. Frields][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://fedoramagazine.org/author/pfrields/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://fedoramagazine.org/wp-content/uploads/2018/10/commandlinequicktips-816x345.jpg
|
||||
[2]: https://fedoramagazine.org/command-line-quick-tips-searching-with-grep/
|
||||
[3]: https://linux.die.net/man/8/netstat
|
||||
@ -1,101 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (beamrolling)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How to transition into a career as a DevOps engineer)
|
||||
[#]: via: (https://opensource.com/article/19/7/how-transition-career-devops-engineer)
|
||||
[#]: author: (Conor Delanbanque https://opensource.com/users/cdelanbanquehttps://opensource.com/users/daniel-ohhttps://opensource.com/users/herontheclihttps://opensource.com/users/marcobravohttps://opensource.com/users/cdelanbanque)
|
||||
|
||||
如何转职为 DevOps 工程师
|
||||
======
|
||||
无论你是刚毕业的大学生，还是想在职业中寻求进步的经验丰富的 IT 专家，这些提示都可以帮你成为 DevOps 工程师。
|
||||
|
||||
![technical resume for hiring new talent][1]
|
||||
|
||||
DevOps 工程是一个备受称赞的热门职业。不管你是刚毕业正在找第一份工作，还是在利用之前的行业经验的同时寻求学习新技能的机会，本指南都能帮你通过正确的步骤成为[ DevOps 工程师][2].
|
||||
|
||||
### 让自己沉浸其中
|
||||
|
||||
首先学习 [DevOps][3] 的基本原理，实践以及方法。在使用工具之前，先了解 DevOps 背后的“为什么”。DevOps 工程师的主要目标是在整个软件开发生命周期（SDLC）中提高速度并保持或提高质量，以提供最大的业务价值。阅读文章，观看 YouTube 视频，参加当地小组聚会或者会议 — 成为热情的 DevOps 社区中的一员，在那里你将从先行者的错误和成功中学习。
|
||||
|
||||
### 考虑你的背景
|
||||
|
||||
如果你有从事技术工作的经历，例如软件开发人员，系统工程师，系统管理员，网络运营工程师或者数据库管理员，那么你已经拥有了广泛的见解和有用的经验，它们可以帮助你在未来成为 DevOps 工程师。如果你在完成计算机科学或任何其他 STEM（译者注，STEM 是科学 Science，技术 Technology，工程 Engineering 和数学 Math四个学科的首字母缩略字）领域的学业后刚开始职业生涯，那么你将拥有在这个过渡期间需要的一些基本踏脚石。
|
||||
|
||||
DevOps 工程师的角色涵盖了广泛的职责。以下是企业最有可能使用他们的三种方向：
|
||||
|
||||
* **偏向于开发（Dev）的 DevOps 工程师**在构建应用中扮演软件开发的角色。他们日常工作的一部分是利用持续集成 / 持续交付（CI/CD），共享仓库，云和容器，但他们不一定负责构建或实施工具。他们了解基础架构，并且在成熟的环境中，能将自己的代码推向生产环境。
|
||||
* **偏向于运维技术（Ops）的 DevOps 工程师**可以与系统工程师或系统管理员进行比较。他们了解软件的开发，但并不会把一天的重心放在构建应用上。相反，他们更有可能支持软件开发团队将手动流程自动化的过程，并提高人员和技术系统的效率。这可能意味着分解遗留代码并用较少繁琐的自动化脚本来运行相同的命令，或者可能意味着安装，配置或维护基础结构和工具。他们确保为任何有需要的团队安装可使用的工具。他们也会通过教授如何利用 CI / CD 和其他 DevOps 实践来帮助团队。
|
||||
* **网站可靠性工程师（SRE）** 就像解决运维和基础设施的软件工程师。SRE 专注于创建可扩展，高度可用且可靠的软件系统。
|
||||
|
||||
|
||||
|
||||
在理想的世界中，DevOps 工程师将了解以上所有领域；这在成熟的科技公司中很常见。然而，顶级银行和许多财富 500 强企业的 DevOps 职位通常会偏向开发（Dev）或运营（Ops）。
|
||||
|
||||
### 要学习的技术
|
||||
|
||||
DevOps 工程师需要了解各种技术才能有效完成工作。无论你的背景如何，请从作为 DevOps 工程师使用和理解的基础技术入手。
|
||||
|
||||
#### 操作系统
|
||||
|
||||
操作系统是所有东西运行的地方，拥有相关的基础知识十分重要。 [Linux ][4]是你最有可能每天使用的操作系统，尽管有的组织会使用 Windows 操作系统。要开始使用，你可以在家中安装 Linux，在那里你可以随心所欲地打破并学习。
|
||||
|
||||
#### 脚本
|
||||
|
||||
接下来，选择一门语言来学习脚本。有很多语言可供选择，包括 Python，Go，Java，Bash，PowerShell，Ruby，和 C / C++。我建议[从 Python 开始][5]，因为它相对容易学习和解释，是最受欢迎的语言之一。Python 通常是为了遵循面向对象编程（OOP）的基础而写的，可用于 Web 开发，软件开发以及创建桌面 GUI 和业务应用程序。
|
||||
|
||||
#### 云
|
||||
|
||||
学习了 [Linux][4] 和 [Python][5] 之后，我认为下一个该学习的是云计算。基础设施不再只是“运维小哥”的事情了，因此你需要接触云平台，例如 AWS 云服务，Azure 或者谷歌云平台。我会从 AWS 开始，因为它有大量免费学习工具，可以帮助你降低作为开发人员，运维，甚至面向业务的组件的任何障碍。事实上，你可能会被它提供的东西所淹没。考虑从 EC2， S3 和 VPC 开始，然后看看你从其中想学到什么。
|
||||
|
||||
#### 编程语言
|
||||
|
||||
如果你带着对软件开发的热情来到 DevOps，请继续提高你的编程技能。DevOps 中的一些优秀和常用语言与脚本相同：Python，Go，Java，Bash，PowerShell，Ruby 和 C / C++。你还应该熟悉 Jenkins 和 Git / Github，你将会在 CI / CD 过程中经常使用到它们。
|
||||
|
||||
#### 容器
|
||||
|
||||
最后，使用 Docker 和编排平台（如 Kubernetes）等工具开始学习[容器化][6]。网上有大量的免费学习资源，大多数城市都有本地的线下小组，你可以在友好的环境中向有经验的人学习（还有披萨和啤酒哦！）。
|
||||
|
||||
#### 其他的呢？
|
||||
|
||||
如果你缺乏开发经验，你依然可以通过对自动化的热情，效率的提高，与他人协作以及改进自己的工作[参与到 DevOps 中][3]来。我仍然建议学习上述工具，但重点不要放在编程 / 脚本语言上。了解基础架构即服务，平台即服务，云平台和 Linux 会非常有用。你可能正在设置工具并学习如何构建有弹性和容错性的系统，并在写代码时利用它们。
|
||||
|
||||
### 找一份 DevOps 的工作
|
||||
|
||||
求职过程会有所不同，具体取决于你是否一直从事技术工作，并且正在进入 DevOps 领域，或者你是刚开始职业生涯的毕业生。
|
||||
|
||||
#### 如果你已经从事技术工作
|
||||
|
||||
如果你正在从一个技术领域转入 DevOps 角色，首先尝试在你当前的公司寻找机会。你可以和其他的团队一起工作吗？尝试影响其他团队成员，寻求建议，并在不离开当前工作的情况下获得新技能。如果做不到这一点，你可能需要换另一家公司。如果你能从上面列出的一些实践，工具和技术中学习，你将能在面试时展示相关知识中占据有利位置。关键是要诚实，不要让自己陷入失败中。大多数招聘主管都了解你不知道所有的答案；如果你能展示你所学到的东西，并解释你愿意学习更多，你应该有机会获得 DevOps 的工作。
|
||||
|
||||
#### 如果你刚开始职业生涯
|
||||
|
||||
申请雇用初级 DevOps 工程师的公司的开放机会。不幸的是，许多公司表示他们希望寻找更富有经验的人，并建议你在获得经验后再申请该职位。这是“我们需要经验丰富的人”的典型，令人沮丧的场景，并且似乎没人愿意给你第一次机会。
|
||||
|
||||
然而，并不是所有求职经历都那么令人沮丧；一些公司专注于培训和提升刚从大学毕业的学生。例如，我工作的 [MThree][7] 聘请来应届毕业生并且对其进行了 8 周的培训。当完成培训后，参与者们可以充分了解到整个 SDLC，并很好地了解它在财富 500 强公司相关环境中的应用。毕业生被聘为 MThree 的客户公司的初级 DevOps 工程师 — MThree 在前 18 - 24 个月内支付全职工资和福利，之后他们将作为直接雇员加入客户。这是弥合从大学到技术职业的间隙的好方法。
|
||||
|
||||
### 总结
|
||||
|
||||
转换成 DevOps 工程师的方法有很多种。这是一条非常有益的职业路线，可能会让你保持繁忙和挑战 — 并增加你的收入潜力。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/7/how-transition-career-devops-engineer
|
||||
|
||||
作者：[Conor Delanbanque][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[beamrolling](https://github.com/beamrolling)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/cdelanbanquehttps://opensource.com/users/daniel-ohhttps://opensource.com/users/herontheclihttps://opensource.com/users/marcobravohttps://opensource.com/users/cdelanbanque
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/hiring_talent_resume_job_career.png?itok=Ci_ulYAH (technical resume for hiring new talent)
|
||||
[2]: https://opensource.com/article/19/7/devops-vs-sysadmin
|
||||
[3]: https://opensource.com/resources/devops
|
||||
[4]: https://opensource.com/resources/linux
|
||||
[5]: https://opensource.com/resources/python
|
||||
[6]: https://opensource.com/article/18/8/sysadmins-guide-containers
|
||||
[7]: https://www.mthreealumni.com/
|
||||
@ -7,26 +7,25 @@
|
||||
[#]: via: (https://opensource.com/article/19/8/dig-binary-files-hexdump)
|
||||
[#]: author: (Seth Kenlon https://opensource.com/users/sethhttps://opensource.com/users/shishz)
|
||||
|
||||
How Hexdump works
|
||||
Hexdump 如何工作
|
||||
======
|
||||
Hexdump helps you investigate the contents of binary files. Learn how
|
||||
hexdump works.
|
||||
![Magnifying glass on code][1]
|
||||
Hexdump 能帮助你查看二进制文件的内容。让我们来学习 Hexdump 如何工作。
|
||||
![代码放大镜][1]
|
||||
|
||||
Hexdump is a utility that displays the contents of binary files in hexadecimal, decimal, octal, or ASCII. It’s a utility for inspection and can be used for [data recovery][2], reverse engineering, and programming.
|
||||
Hexdump 是个用十六进制、十进制、八进制数或 ASCII 码显示二进制文件内容的工具。它是个用于检查的工具，也可用于[数据恢复][2]、逆向工程和编程。
|
||||
|
||||
### Learning the basics
|
||||
### 学习基本用法
|
||||
|
||||
Hexdump provides output with very little effort on your part and depending on the size of the file you’re looking at, there can be a lot of output. For the purpose of this article, create a 1x1 PNG file. You can do this with a graphics application such as [GIMP][3] or [Mtpaint][4], or you can create it in a terminal with [ImageMagick][5].
|
||||
Hexdump 让你毫不费力地得到输出结果，依你所查看文件的尺寸，输出结果可能会非常多。本文中我们会创建一个 1x1 像素的 PNG 文件。你可以用图像处理应用如 [GIMP][3] 或 [Mtpaint][4] 来创建该文件，或者也可以在终端内用 [ImageMagick][5] 创建。
|
||||
|
||||
Here’s a command to generate a 1x1 pixel PNG with ImageMagick:
|
||||
用 ImagiMagick 生成 1x1 像素 PNG 文件的命令如下：
|
||||
|
||||
|
||||
```
|
||||
$ convert -size 1x1 canvas:black pixel.png
|
||||
```
|
||||
|
||||
You can confirm that this file is a PNG with the **file** command:
|
||||
你可以用 **file** 命令确认此文件是 PNG 格式：
|
||||
|
||||
|
||||
```
|
||||
@ -34,7 +33,7 @@ $ file pixel.png
|
||||
pixel.png: PNG image data, 1 x 1, 1-bit grayscale, non-interlaced
|
||||
```
|
||||
|
||||
You may wonder how the **file** command is able to determine what kind of file it is. Coincidentally, that’s what **hexdump** will reveal. For now, you can view your one-pixel graphic in the image viewer of your choice (it looks like this: **.** ), or you can view what’s inside the file with **hexdump**:
|
||||
你可能好奇 **file** 命令是如何判断文件是什么类型。巧的是，那正是 **hexdump** 将要揭示的。眼下你可以用你常用的图像查看软件来看看你的单一像素图片（它看上去就像这样：**.**），或者你可以用 **hexdump** 查看文件内部：
|
||||
|
||||
|
||||
```
|
||||
@ -59,11 +58,11 @@ $ hexdump pixel.png
|
||||
0000102
|
||||
```
|
||||
|
||||
What you’re seeing is the contents of the sample PNG file through a lens you may have never used before. It’s the exact same data you see in an image viewer, encoded in a way that’s probably unfamiliar to you.
|
||||
透过一个你以前可能从未用过的镜头，你所见的是该示例 PNG 文件的内容。它和你在图像查看软件中看到的是完全一样的数据，只是用一种你或许不熟悉的方式编码。
|
||||
|
||||
### Extracting familiar strings
|
||||
### 提取熟悉的字符串
|
||||
|
||||
Just because the default data dump seems meaningless, that doesn’t mean it’s devoid of valuable information. You can translate this output or at least the parts that actually translate, to a more familiar character set with the **\--canonical** option:
|
||||
尽管默认的数据输出结果看上去毫无意义，那并不意味着其中没有有价值的信息。你可以用 **\--canonical** 选项将输出结果，或至少是其中可翻译的部分，翻译成更加熟悉的字符集：
|
||||
|
||||
|
||||
```
|
||||
@ -88,11 +87,11 @@ $ hexdump --canonical foo.png
|
||||
00000102
|
||||
```
|
||||
|
||||
In the right column, you see the same data that’s on the left but presented as ASCII. If you look carefully, you can pick out some useful information, such as the file’s format (PNG) and—toward the bottom—the date and time the file was created and last modified. The dots represent symbols that aren’t present in the ASCII character set, which is to be expected because binary formats aren’t restricted to mundane letters and numbers.
|
||||
在右侧的列中，你看到的是和左侧一样的数据，但是以 ASCII 码展现的。如果你仔细看，你可以从中挑选出一些有用的信息，如文件格式（PNG）以及——向文件底部寻找——文件创建、修改日期和时间。
|
||||
|
||||
The **file** command knows from the first 8 bytes what this file is. The [libpng specification][6] alerts programmers what to look for. You can see that within the first 8 bytes of this image file, specifically, is the string **PNG**. That fact is significant because it reveals how the **file** command knows what kind of file to report.
|
||||
**file** 命令通过头 8 个字节获取文件类型。程序员会参考 [libpng 规范][6] 来知晓需要查看什么。具体而言，那就是你能在该图像文件的头 8 个字节中看到的字符串 **PNG**。这个事实显而易见，因为它揭示了 **file** 命令是如何知道要报告的文件类型。
|
||||
|
||||
You can also control how many bytes **hexdump** displays, which is useful with files larger than one pixel:
|
||||
你也可以控制 **hexdump** 显示多少字节，这在处理大于一个像素的文件时很实用：
|
||||
|
||||
|
||||
```
|
||||
@ -101,13 +100,14 @@ $ hexdump --length 8 pixel.png
|
||||
0000008
|
||||
```
|
||||
|
||||
You don’t have to limit **hexdump** to PNG or graphic files. You can run **hexdump** against binaries you run on a daily basis as well, such as [ls][7], [rsync][8], or any binary format you want to inspect.
|
||||
**hexdump** 不只限于查看 PNG 或图像文件。你也可以用 **hexdump** 查看你日常使用的二进制文件，如 [ls][7]，[rsync][8]，或你想检查的任何二进制文件。
|
||||
|
||||
### Implementing cat with hexdump
|
||||
|
||||
If you read the PNG spec, you may notice that the data in the first 8 bytes looks different than what **hexdump** provides. Actually, it’s the same data, but it’s presented using a different conversion. So, the output of **hexdump** is true, but not always directly useful to you, depending on what you’re looking for. For that reason, **hexdump** has options to format and convert the raw data it dumps.
|
||||
### 用 hexdump 实现 cat 命令
|
||||
|
||||
The conversion options can get complex, so it’s useful to practice with something trivial first. Here’s a gentle introduction to formatting **hexdump** output by reimplementing the [**cat**][9] command. First, run **hexdump** on a text file to see its raw data. You can usually find a copy of the [GNU General Public License (GPL)][10] license somewhere on your hard drive, or you can use any text file you have handy. Your output may differ, but here’s how to find a copy of the GPL on your system (or at least part of it):
|
||||
阅读 PNG 规范的时候你可能会注意到头 8 个字节中的数据与 **hexdump** 提供的结果看上去不一样。实际上，那是一样的数据，但以一种不同的转换方式展现出来。所以 **hexdump** 的输出是正确的，但取决于你在寻找的信息，其输出结果对你而言不总是直接了当的。出于这个原因，**hexdump** 有一些选项可供用于定义格式和转化其转储的原始数据。
|
||||
|
||||
转换选项可以很复杂，所以用无关紧要的东西练习会比较实用。下面这个简易的介绍，通过重新实现 [**cat**][9] 命令来演示如何格式化 **hexdump** 的输出。首先，对一个文本文件运行 **hexdump** 来查看其原始数据。通常你可以在硬盘上某处找到 [<ruby>GNU 公共授权<rt>GNU General Public License</rt></ruby>（GPL）][10]的一份拷贝，也可以用你手头的任何文本文件。你的输出结果可能不同，但下面是如何在你的系统中找到一份 GPL（或至少其部分）的拷贝：
|
||||
|
||||
|
||||
```
|
||||
@ -115,7 +115,7 @@ $ find /usr/share/doc/ -type f -name "COPYING" | tail -1
|
||||
/usr/share/doc/libblkid-devel/COPYING
|
||||
```
|
||||
|
||||
Run **hexdump** against it:
|
||||
对其运行 **hexdump**：
|
||||
|
||||
|
||||
```
|
||||
@ -132,9 +132,9 @@ $ hexdump /usr/share/doc/libblkid-devel/COPYING
|
||||
[...]
|
||||
```
|
||||
|
||||
If the file’s output is very long, use the **\--length** (or **-n** for short) to make it manageable for yourself.
|
||||
如果该文件输出结果很长，用 **\length**（或短选项 **-n**）来控制输出长度使其易于管理。
|
||||
|
||||
The raw data probably means nothing to you, but you already know how to convert it to ASCII:
|
||||
原始数据对你而言可能没什么意义，但你已经知道如何将其转换为 ASCII 码：
|
||||
|
||||
|
||||
```
|
||||
@ -150,9 +150,10 @@ hexdump --canonical /usr/share/doc/libblkid-devel/COPYING
|
||||
[...]
|
||||
```
|
||||
|
||||
That output is helpful but unwieldy and difficult to read. To format **hexdump**’s output beyond what’s offered by its own options, use **\--format** (or **-e**) along with specialized formatting codes. The shorthand used for formatting is similar to what the **printf** command uses, so if you are familiar with **printf** statements, you may find **hexdump** formatting easier to learn.
|
||||
这个输出结果有帮助但太累赘且难于阅读。要将 **hexdump** 的输出结果转换为其选项不支持的其他格式，可组合使用 **\--format**（或 **-e**）和专门的格式代码。用来自定义格式的代码和 **printf** 命令使用的类似，所以如果你熟悉 **printf** 语句，你可能会觉得 **hexdump** 自定义格式不难学会。
|
||||
|
||||
In **hexdump**, the character sequence **%_p** tells **hexdump** to print a character in your system’s default character set. All formatting notation for the **\--format** option must be enclosed in _single quotes_:
|
||||
|
||||
在 **hexdump** 中，字符串 **%_p** 告诉 **hexdump** 用你系统的默认字符集输出字符。**\--format** 选项的所有格式符号必须以_单引号_包括起来：
|
||||
|
||||
|
||||
```
|
||||
@ -165,9 +166,9 @@ The complete text of the license is available in the..*
|
||||
/Documentation/licenses/COPYING.LGPL-2.1-or-later file..
|
||||
```
|
||||
|
||||
This output is better, but still inconvenient to read. Traditionally, UNIX text files assume an 80-character output width (because long ago, monitors tended to fit only 80 characters across).
|
||||
这次的输出好些了，但依然不方便阅读。传统上 UNIX 文本文件假定80个字符的输出宽度（因为很久以前显示器一行只能显示80个字符）。
|
||||
|
||||
While this output isn’t bound by formatting, you can force **hexdump** to process 80 bytes at a time with additional options. Specifically, by dividing 80 by one, you can tell **hexdump** to treat 80 bytes as one unit:
|
||||
尽管这个输出结果未被自定义格式限制输出宽度，你可以用附加选项强制 **hexdump** 一次处理 80 字节。具体而言，通过 80 除以 1 这种形式，你可以告诉 **hexdump** 将 80 字节作为一个单元对待：
|
||||
|
||||
|
||||
```
|
||||
@ -175,11 +176,11 @@ $ hexdump -e'80/1 "%_p"' /usr/share/doc/libblkid-devel/COPYING
|
||||
This library is free software; you can redistribute it and/or.modify it under the terms of the GNU Lesser General Public.License as published by the Free Software Foundation; either.version 2.1 of the License, or (at your option) any later.version...The complete text of the license is available in the.../Documentation/licenses/COPYING.LGPL-2.1-or-later file..
|
||||
```
|
||||
|
||||
Now the file is processed in 80-byte chunks, but it’s lost any sense of new lines. You can add your own with the **\n** character, which in UNIX represents a new line:
|
||||
现在该文件被分割成 80 字节的块处理，但没有任何换行。你可以用 **\n** 字符自行添加换行，在 UNIX 中它代表换行：
|
||||
|
||||
|
||||
```
|
||||
$ hexdump -e'80/1 "%_p""\n"'
|
||||
$ hexdump -e'80/1 "%_p""\n"' /usr/share/doc/libblkid-devel/COPYING
|
||||
This library is free software; you can redistribute it and/or.modify it under th
|
||||
e terms of the GNU Lesser General Public.License as published by the Free Softwa
|
||||
re Foundation; either.version 2.1 of the License, or (at your option) any later.
|
||||
@ -187,13 +188,13 @@ version...The complete text of the license is available in the.../Documentation/
|
||||
licenses/COPYING.LGPL-2.1-or-later file..
|
||||
```
|
||||
|
||||
You have now (approximately) implemented the **cat** command with **hexdump** formatting.
|
||||
现在你已经（大致上）用 **hexdump** 自定义格式实现了 **cat** 命令。
|
||||
|
||||
### Controlling the output
|
||||
### 控制输出结果
|
||||
|
||||
Formatting is, realistically, how you make **hexdump** useful. Now that you’re familiar, in principle at least, with **hexdump** formatting, you can make the output of **hexdump -n 8** match the output of the PNG header as described by the official **libpng** spec.
|
||||
实际上自定义格式是让 **hexdump** 变得有用的方法。现在你已经，至少是原则上，熟悉 **hexdump** 自定义格式，你可以让 **hexdump -n 8** 的输出结果跟 **libpng** 官方规范中描述的 PNG 文件头相匹配了。
|
||||
|
||||
First, you know that you want **hexdump** to process the PNG file in 8-byte chunks. Furthermore, you may know by integer recognition that the PNG spec is documented in decimal, which is represented by **%d** according to the **hexdump** documentation:
|
||||
首先，你知道你希望 **hexdump** 以 8 字节的块来处理 PNG 文件。此外，你可能通过识别整数知道 PNG 格式规范以十进制数表述，根据 **hexdump** 文档十进制用 **%d** 来表示：
|
||||
|
||||
|
||||
```
|
||||
@ -201,7 +202,7 @@ $ hexdump -n8 -e'8/1 "%d""\n"' pixel.png
|
||||
13780787113102610
|
||||
```
|
||||
|
||||
You can make the output perfect by adding a blank space after each integer:
|
||||
你可以在每个整数后面加个空格使输出结果变得完美：
|
||||
|
||||
|
||||
```
|
||||
@ -209,11 +210,11 @@ $ hexdump -n8 -e'8/1 "%d ""\n"' pixel.png
|
||||
137 80 78 71 13 10 26 10
|
||||
```
|
||||
|
||||
The output is now a perfect match to the PNG specification.
|
||||
现在输出结果跟 PNG 规范完美匹配了。
|
||||
|
||||
### Hexdumping for fun and profit
|
||||
### 为乐趣和益处使用 hexdump
|
||||
|
||||
Hexdump is a fascinating tool that not only teaches you more about how computers process and convert information, but also about how file formats and compiled binaries function. You should try running **hexdump** on files at random throughout the day as you work. You never know what kinds of information you may find, nor when having that insight may be useful.
|
||||
Hexdump 是个迷人的工具，不仅让你更多地领会计算机如何处理和转换信息，而且让你了解文件格式和编译过的二进制文件如何工作。工作的时候你应该随机地试着对不同文件运行 **hexdump**。你永远不知道你会发现什么样的信息，或是什么时候具有这种洞察力会很实用。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -221,7 +222,7 @@ via: https://opensource.com/article/19/8/dig-binary-files-hexdump
|
||||
|
||||
作者：[Seth Kenlon][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
译者：[0x996](https://github.com/0x996)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
Loading…
Reference in New Issue
Block a user