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Ricky Gong
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一位开发者的 Linux 容器之旅
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================================================================================
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我告诉你一个秘密：使得我的应用程序进入到全世界的 DevOps 云计算之类的东西对我来说仍然有一点神秘。但随着时间流逝，我意识到理解大规模的机器增减和应用程序部署的来龙去脉对一个开发者来说是非常重要的知识。这类似于成为一个专业的音乐家，当然你肯定需要知道如何使用你的乐器，但是，如果你不知道一个录音棚是如何工作的，或者如何适应一个交响乐团，那么你在这样的环境中工作会变得非常困难。
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在软件开发的世界里，使你的代码进入我们的更大的世界如同把它编写出来一样重要。DevOps 重要，而且是很重要。
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因此，为了弥合开发（Dev）和部署（Ops）之间的空隙，我会从头开始介绍容器技术。为什么是容器？因为有强力的证据表明，容器是机器抽象的下一步：使计算机成为场所而不再是一个东西。理解容器是我们共同的旅程。
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在这篇文章中，我会介绍容器化（containerization）背后的概念。包括容器和虚拟机的区别，以及容器构建背后的逻辑以及它是如何适应应用程序架构的。我会探讨轻量级的 Linux 操作系统是如何适应容器生态系统。我还会讨论使用镜像创建可重用的容器。最后我会介绍容器集群如何使你的应用程序可以快速扩展。
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在后面的文章中，我会一步一步向你介绍容器化一个示例应用程序的过程，以及如何为你的应用程序容器创建一个托管集群。同时，我会向你展示如何使用 Deis 将你的示例应用程序部署到你本地系统以及多种云供应商的虚拟机上。
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让我们开始吧。
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### 虚拟机的好处 ###
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为了理解容器如何适应事物发展，你首先要了解容器的前任：虚拟机。
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[虚拟机][1] （virtual machine (VM)）是运行在物理宿主机上的软件抽象。配置一个虚拟机就像是购买一台计算机：你需要定义你想要的 CPU 数目、RAM 和磁盘存储容量。配置好了机器后，你为它加载操作系统，以及你想让虚拟机支持的任何服务器或者应用程序。
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虚拟机允许你在一台硬件主机上运行多个模拟计算机。这是一个简单的示意图：
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虚拟机可以让你能充分利用你的硬件资源。你可以购买一台巨大的、轰隆作响的机器，然后在上面运行多个虚拟机。你可以有一个数据库虚拟机以及很多运行相同版本的定制应用程序的虚拟机所构成的集群。你可以在有限的硬件资源获得很多的扩展能力。如果你觉得你需要更多的虚拟机而且你的宿主硬件还有容量，你可以添加任何你需要的虚拟机。或者，如果你不再需要一个虚拟机，你可以关闭该虚拟机并删除虚拟机镜像。
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### 虚拟机的局限 ###
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但是，虚拟机确实有局限。
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如上面所示，假如你在一个主机上创建了三个虚拟机。主机有 12 个 CPU，48 GB 内存和 3TB 的存储空间。每个虚拟机配置为有 4 个 CPU，16 GB 内存和 1TB 存储空间。到现在为止，一切都还好。主机有这个容量。
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但这里有个缺陷。所有分配给一个虚拟机的资源，无论是什么，都是专有的。每台机器都分配了 16 GB 的内存。但是，如果第一个虚拟机永不会使用超过 1GB 分配的内存，剩余的 15 GB 就会被浪费在那里。如果第三个虚拟机只使用分配的 1TB 存储空间中的 100GB，其余的 900GB 就成为浪费空间。
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这里没有资源的流动。每台虚拟机拥有分配给它的所有资源。因此，在某种方式上我们又回到了虚拟机之前，把大部分金钱花费在未使用的资源上。
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虚拟机还有*另一个*缺陷。让它们跑起来需要很长时间。如果你处于基础设施需要快速增长的情形，即使增加虚拟机是自动的，你仍然会发现你的很多时间都浪费在等待机器上线。
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### 来到：容器 ###
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概念上来说，容器是一个 Linux 进程，Linux 认为它只是一个运行中的进程。该进程只知道它被告知的东西。另外，在容器化方面，该容器进程也分配了它自己的 IP 地址。这点很重要，重要的事情讲三遍，这是第二遍。**在容器化方面，容器进程有它自己的 IP 地址。**一旦给予了一个 IP 地址，该进程就是宿主网络中可识别的资源。然后，你可以在容器管理器上运行命令，使容器 IP 映射到主机中能访问公网的 IP 地址。建立了该映射，无论出于什么意图和目的，容器就是网络上一个可访问的独立机器，从概念上类似于虚拟机。
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这是第三遍，容器是拥有不同 IP 地址从而使其成为网络上可识别的独立 Linux 进程。下面是一个示意图：
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容器/进程以动态、合作的方式共享主机上的资源。如果容器只需要 1GB 内存，它就只会使用 1GB。如果它需要 4GB，就会使用 4GB。CPU 和存储空间利用也是如此。CPU、内存和存储空间的分配是动态的，和典型虚拟机的静态方式不同。所有这些资源的共享都由容器管理器来管理。
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最后，容器能非常快速地启动。
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因此，容器的好处是：**你获得了虚拟机独立和封装的好处，而抛弃了静态资源专有的缺陷**。另外，由于容器能快速加载到内存，在扩展到多个容器时你能获得更好的性能。
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### 容器托管、配置和管理 ###
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托管容器的计算机运行着被剥离的只剩下主要部分的某个 Linux 版本。现在，宿主计算机流行的底层操作系统是之前提到的 [CoreOS][2]。当然还有其它，例如 [Red Hat Atomic Host][3] 和 [Ubuntu Snappy][4]。
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该 Linux 操作系统被所有容器所共享，减少了容器足迹的重复和冗余。每个容器只包括该容器特有的部分。下面是一个示意图：
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你可以用它所需的组件来配置容器。一个容器组件被称为**层（layer）**。层是一个容器镜像，（你会在后面的部分看到更多关于容器镜像的介绍）。你从一个基本层开始，这通常是你想在容器中使用的操作系统。（容器管理器只提供你所要的操作系统在宿主操作系统中不存在的部分。）当你构建你的容器配置时，你需要添加层，例如你想要添加网络服务器时这个层就是 Apache，如果容器要运行脚本，则需要添加 PHP 或 Python 运行时环境。
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分层非常灵活。如果应用程序或者服务容器需要 PHP 5.2 版本，你相应地配置该容器即可。如果你有另一个应用程序或者服务需要 PHP 5.6 版本，没问题，你可以使用 PHP 5.6 配置该容器。不像虚拟机，更改一个版本的运行时依赖时你需要经过大量的配置和安装过程；对于容器你只需要在容器配置文件中重新定义层。
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所有上面描述的容器的各种功能都由一个称为容器管理器（container manager）的软件控制。现在，最流行的容器管理器是 [Docker][5] 和 [Rocket][6]。上面的示意图展示了容器管理器是 Docker，宿主操作系统是 CentOS 的主机情景。
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### 容器由镜像构成 ###
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当你需要将我们的应用程序构建到容器时，你就要编译镜像。镜像代表了你的容器需要完成其工作的容器模板。（容器里可以在容器里面，如下图）。镜像存储在注册库（registry）中，注册库通过网络访问。
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从概念上讲，注册库类似于一个使用 Java 的人眼中的 [Maven][7] 仓库、使用 .NET 的人眼中的 [NuGet][8] 服务器。你会创建一个列出了你应用程序所需镜像的容器配置文件。然后你使用容器管理器创建一个包括了你的应用程序代码以及从容器注册库中下载的部分资源。例如，如果你的应用程序包括了一些 PHP 文件，你的容器配置文件会声明你会从注册库中获取 PHP 运行时环境。另外，你还要使用容器配置文件声明需要复制到容器文件系统中的 .php 文件。容器管理器会封装你应用程序的所有东西为一个独立容器，该容器将会在容器管理器的管理下运行在宿主计算机上。
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这是一个容器创建背后概念的示意图：
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让我们仔细看看这个示意图。
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（1）代表一个定义了你容器所需东西以及你容器如何构建的容器配置文件。当你在主机上运行容器时，容器管理器会读取该配置文件，从云上的注册库中获取你需要的容器镜像，（2）将镜像作为层添加到你的容器中。
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另外，如果组成镜像需要其它镜像，容器管理器也会获取这些镜像并把它们作为层添加进来。（3）容器管理器会将需要的文件复制到容器中。
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如果你使用了配置（provisioning）服务，例如 [Deis][9]，你刚刚创建的应用程序容器做成镜像，（4）配置服务会将它部署到你选择的云供应商上，比如类似 AWS 和 Rackspace 云供应商。
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### 集群中的容器 ###
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好了。这里有一个很好的例子说明了容器比虚拟机提供了更好的配置灵活性和资源利用率。但是，这并不是全部。
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容器真正的灵活是在集群中。记住，每个容器有一个独立的 IP 地址。因此，能把它放到负载均衡器后面。将容器放到负载均衡器后面，这就上升了一个层面。
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你可以在一个负载均衡容器后运行容器集群以获得更高的性能和高可用计算。这是一个例子：
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假如你开发了一个资源密集型的应用程序，例如图片处理。使用类似 [Deis][9] 的容器配置技术，你可以创建一个包括了你图片处理程序以及你图片处理程序需要的所有资源的容器镜像。然后，你可以部署一个或多个容器镜像到主机上的负载均衡器下。一旦创建了容器镜像，你可以随时使用它。当系统繁忙时可以添加更多的容器实例来满足手中的工作。
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这里还有更多好消息。每次添加实例到环境中时，你不需要手动配置负载均衡器以便接受你的容器镜像。你可以使用服务发现技术让容器告知均衡器它可用。然后，一旦获知，均衡器就会将流量分发到新的结点。
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### 全部放在一起 ###
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容器技术完善了虚拟机缺失的部分。类似 CoreOS、RHEL Atomic、和 Ubuntu 的 Snappy 宿主操作系统，和类似 Docker 和 Rocket 的容器管理技术结合起来，使得容器变得日益流行。
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尽管容器变得更加越来越普遍，掌握它们还是需要一段时间。但是，一旦你懂得了它们的窍门，你可以使用类似 [Deis][9] 这样的配置技术使容器创建和部署变得更加简单。
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从概念上理解容器和进一步实际使用它们完成工作一样重要。但我认为不实际动手把想法付诸实践，概念也难以理解。因此，我们该系列的下一阶段就是：创建一些容器。
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--------------------------------------------------------------------------------
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via: https://deis.com/blog/2015/developer-journey-linux-containers
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作者：[Bob Reselman][a]
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译者：[ictlyh](http://www.mutouxiaogui.cn/blog/)
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校对：[wxy](https://github.com/wxy)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
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[a]:https://deis.com/blog
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[1]:https://en.wikipedia.org/wiki/Virtual_machine
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[2]:https://coreos.com/using-coreos/
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[3]:http://www.projectatomic.io/
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[4]:https://developer.ubuntu.com/en/snappy/
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[5]:https://www.docker.com/
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[6]:https://coreos.com/blog/rocket/
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[7]:https://en.wikipedia.org/wiki/Apache_Maven
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[8]:https://www.nuget.org/
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[9]:http://deis.com/learn
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@ -1,11 +1,10 @@
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第七部分 - 在 Linux 客户端配置基于 Kerberos 身份验证的 NFS 服务器
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RHCE 系列（七）：在 Linux 客户端配置基于 Kerberos 身份验证的 NFS 服务器
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================================================================================
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在本系列的前一篇文章，我们回顾了[如何在可能包括多种类型操作系统的网络上配置 Samba 共享][1]。现在，如果你需要为一组类-Unix 客户端配置文件共享，很自然的你会想到网络文件系统，或简称 NFS。
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在本系列的前一篇文章，我们回顾了[如何在可能包括多种类型操作系统的网络上配置 Samba 共享][1]。现在，如果你需要为一组类 Unix 客户端配置文件共享，很自然的你会想到网络文件系统，或简称 NFS。
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RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服务器
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*RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服务器*
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在这篇文章中我们会介绍配置基于 Kerberos 身份验证的 NFS 共享的整个流程。假设你已经配置好了一个 NFS 服务器和一个客户端。如果还没有，可以参考 [安装和配置 NFS 服务器][2] - 它列出了需要安装的依赖软件包并解释了在进行下一步之前如何在服务器上进行初始化配置。
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#### 创建 NFS 组并配置 NFS 共享目录 ####
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1. 新建一个名为 nfs 的组并给它添加用户 nfsnobody，然后更改 /nfs 目录的权限为 0770，组属主为 nfs。于是，nfsnobody（对应请求用户）在共享目录有写的权限，你就不需要在 /etc/exports 文件中使用 no_root_squash（译者注：设为 root_squash 意味着在访问 NFS 服务器上的文件时，客户机上的 root 用户不会被当作 root 用户来对待）。
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1、 新建一个名为 nfs 的组并给它添加用户 nfsnobody，然后更改 /nfs 目录的权限为 0770，组属主为 nfs。于是，nfsnobody（对应请求用户）在共享目录有写的权限，你就不需要在 /etc/exports 文件中使用 no_root_squash（LCTT 译注：设为 root_squash 意味着在访问 NFS 服务器上的文件时，客户机上的 root 用户不会被当作 root 用户来对待）。
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# groupadd nfs
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# usermod -a -G nfs nfsnobody
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# chmod 0770 /nfs
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# chgrp nfs /nfs
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2. 像下面那样更改 export 文件（/etc/exports）只允许从 box1 使用 Kerberos 安全验证的访问（sec=krb5）。
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2、 像下面那样更改 export 文件（/etc/exports）只允许从 box1 使用 Kerberos 安全验证的访问（sec=krb5）。
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**注意**：anongid 的值设置为之前新建的组 nfs 的 GID：
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**exports – 添加 NFS 共享**
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----------
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/nfs box1(rw,sec=krb5,anongid=1004)
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3. 再次 exprot（-r）所有（-a）NFS 共享。为输出添加详情（-v）是个好主意，因为它提供了发生错误时解决问题的有用信息：
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3、 再次 exprot（-r）所有（-a）NFS 共享。为输出添加详情（-v）是个好主意，因为它提供了发生错误时解决问题的有用信息：
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# exportfs -arv
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4. 重启并启用 NFS 服务器以及相关服务。注意你不需要启动 nfs-lock 和 nfs-idmapd，因为系统启动时其它服务会自动启动它们：
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4、 重启并启用 NFS 服务器以及相关服务。注意你不需要启动 nfs-lock 和 nfs-idmapd，因为系统启动时其它服务会自动启动它们：
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# systemctl restart rpcbind nfs-server nfs-lock nfs-idmap
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# systemctl enable rpcbind nfs-server
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@ -61,14 +58,12 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
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正如你看到的，为了简便，NFS 服务器和 KDC 在同一台机器上，当然如果你有更多可用机器你也可以把它们安装在不同的机器上。两台机器都在 `mydomain.com` 域。
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最后同样重要的是，Kerberos 要求客户端和服务器中至少有一个域名解析的基本模式和[网络时间协议][5]服务，因为 Kerberos 身份验证的安全一部分基于时间戳。
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最后同样重要的是，Kerberos 要求客户端和服务器中至少有一个域名解析的基本方式和[网络时间协议][5]服务，因为 Kerberos 身份验证的安全一部分基于时间戳。
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为了配置域名解析，我们在客户端和服务器中编辑 /etc/hosts 文件：
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**host 文件 – 为域添加 DNS**
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----------
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192.168.0.18 box1.mydomain.com box1
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192.168.0.20 box2.mydomain.com box2
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@ -82,10 +77,9 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
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||||
|
||||
# chronyc tracking
|
||||
|
||||
|
||||
|
||||
|
||||
用 Chrony 同步服务器时间
|
||||
*用 Chrony 同步服务器时间*
|
||||
|
||||
### 安装和配置 Kerberos ###
|
||||
|
||||
@ -109,7 +103,7 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
|
||||
|
||||
|
||||
|
||||
创建 Kerberos 数据库
|
||||
*创建 Kerberos 数据库*
|
||||
|
||||
下一步，使用 kadmin.local 工具为 root 创建管理权限：
|
||||
|
||||
@ -129,7 +123,7 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
|
||||
|
||||
|
||||
|
||||
添加 Kerberos 到 NFS 服务器
|
||||
*添加 Kerberos 到 NFS 服务器*
|
||||
|
||||
为 root/admin 获取和缓存票据授权票据（ticket-granting ticket）：
|
||||
|
||||
@ -138,7 +132,7 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
|
||||
|
||||
|
||||
|
||||
缓存 Kerberos
|
||||
*缓存 Kerberos*
|
||||
|
||||
真正使用 Kerberos 之前的最后一步是保存被授权使用 Kerberos 身份验证的规则到一个密钥表文件（在服务器中）：
|
||||
|
||||
@ -154,7 +148,7 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
|
||||
|
||||
|
||||
|
||||
挂载 NFS 共享
|
||||
*挂载 NFS 共享*
|
||||
|
||||
现在让我们卸载共享，在客户端中重命名密钥表文件（模拟它不存在）然后试着再次挂载共享目录：
|
||||
|
||||
@ -163,7 +157,7 @@ RHCE 系列：第七部分 - 设置使用 Kerberos 进行身份验证的 NFS 服
|
||||
|
||||
|
||||
|
||||
挂载/卸载 Kerberos NFS 共享
|
||||
*挂载/卸载 Kerberos NFS 共享*
|
||||
|
||||
现在你可以使用基于 Kerberos 身份验证的 NFS 共享了。
|
||||
|
||||
@ -177,12 +171,12 @@ via: http://www.tecmint.com/setting-up-nfs-server-with-kerberos-based-authentica
|
||||
|
||||
作者：[Gabriel Cánepa][a]
|
||||
译者：[ictlyh](http://www.mutouxiaogui.cn/blog/)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
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]:http://www.tecmint.com/author/gacanepa/
|
||||
[1]:http://www.tecmint.com/setup-samba-file-sharing-for-linux-windows-clients/
|
||||
[1]:https://linux.cn/article-6550-1.html
|
||||
[2]:http://www.tecmint.com/configure-nfs-server/
|
||||
[3]:http://www.tecmint.com/selinux-essentials-and-control-filesystem-access/
|
||||
[4]:http://www.tecmint.com/firewalld-rules-for-centos-7/
|
||||
@ -1,45 +0,0 @@
|
||||
sevenot translating
|
||||
Curious about Linux? Try Linux Desktop on the Cloud
|
||||
================================================================================
|
||||
Linux maintains a very small market share as a desktop operating system. Current surveys estimate its share to be a mere 2%; contrast that with the various strains (no pun intended) of Windows which total nearly 90% of the desktop market. For Linux to challenge Microsoft's monopoly on the desktop, there needs to be a simple way of learning about this different operating system. And it would be naive to believe a typical Windows user is going to buy a second machine, tinker with partitioning a hard disk to set up a multi-boot system, or just jump ship to Linux without an easy way back.
|
||||
|
||||
|
||||
|
||||
We have examined a number of risk-free ways users can experiment with Linux without dabbling with partition management. Various options include Live CD/DVDs, USB keys and desktop virtualization software. For the latter, I can strongly recommend VMWare (VMWare Player) or Oracle VirtualBox, two relatively easy and free ways of installing and running multiple operating systems on a desktop or laptop computer. Each virtual machine has its own share of CPU, memory, network interfaces etc which is isolated from other virtual machines. But virtual machines still require some effort to get Linux up and running, and a reasonably powerful machine. Too much effort for a mere inquisitive mind.
|
||||
|
||||
It can be difficult to break down preconceptions. Many Windows users will have experimented with free software that is available on Linux. But there are many facets to learn on Linux. And it takes time to become accustomed to the way things work in Linux.
|
||||
|
||||
Surely there should be an effortless way for a beginner to experiment with Linux for the first time? Indeed there is; step forward the online cloud lab.
|
||||
|
||||
### LabxNow ###
|
||||
|
||||
|
||||
|
||||
LabxNow provides a free service for general users offering Linux remote desktop over the browser. The developers promote the service as having a personal remote lab (to play around, develop, whatever!) that will be accessible from anywhere, with the internet of course.
|
||||
|
||||
The service currently offers a free virtual private server with 2 cores, 4GB RAM and 10GB SSD space. The service runs on a 4 AMD 6272 CPU with 128GB RAM.
|
||||
|
||||
#### Features include: ####
|
||||
|
||||
- Machine images: Ubuntu 14.04 with Xfce 4.10, RHEL 6.5, CentOS with Gnome, and Oracle
|
||||
- Hardware: CPU - 1 or 2 cores; RAM: 512MB, 1GB, 2GB or 4GB
|
||||
- Fast network for data transfers
|
||||
- Works with all popular browsers
|
||||
- Install anything, run anything - an excellent way to experiment and learn all about Linux without any risk
|
||||
- Easily add, delete, manage and customize VMs
|
||||
- Share VMs, Remote desktop support
|
||||
|
||||
All you need is a reasonable Internet connected device. Forget about high cost VPS, domain space or hardware support. LabxNow offers a great way of experimenting with Ubuntu, RHEL and CentOS. It gives Windows users an excellent environment to dip their toes into the wonderful world of Linux. Further, it allows users to do (programming) work from anywhere in the word without having the stress of installing Linux on each machine. Point your web browser at [www.labxnow.org/labxweb/][1].
|
||||
|
||||
There are other services (mostly paid services) that allow users to experiment with Linux. These include Cloudsigma which offers a free 7 day trial, and Icebergs.io (full root access via HTML5). But for now, LabxNow gets my recommendation.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.linuxlinks.com/article/20151003095334682/LinuxCloud.html
|
||||
|
||||
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
|
||||
|
||||
[1]:https://www.labxnow.org/labxweb/
|
||||
@ -1,3 +1,4 @@
|
||||
sevenot translating
|
||||
A Linux User Using ‘Windows 10′ After More than 8 Years – See Comparison
|
||||
================================================================================
|
||||
Windows 10 is the newest member of windows NT family of which general availability was made on July 29, 2015. It is the successor of Windows 8.1. Windows 10 is supported on Intel Architecture 32 bit, AMD64 and ARMv7 processors.
|
||||
@ -341,4 +342,4 @@ via: http://www.tecmint.com/a-linux-user-using-windows-10-after-more-than-8-year
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://www.tecmint.com/author/avishek/
|
||||
[1]:https://www.microsoft.com/en-us/software-download/windows10ISO
|
||||
[1]:https://www.microsoft.com/en-us/software-download/windows10ISO
|
||||
|
||||
77
sources/talk/20151117 How bad a boss is Linus Torvalds.md
Normal file
77
sources/talk/20151117 How bad a boss is Linus Torvalds.md
Normal file
@ -0,0 +1,77 @@
|
||||
How bad a boss is Linus Torvalds?
|
||||
================================================================================
|
||||
|
||||
|
||||
*Linus Torvalds addressed a packed auditorium of Linux enthusiasts during his speech at the LinuxWorld show in San Jose, California, on August 10, 1999. Credit: James Niccolai*
|
||||
|
||||
**It depends on context. In the world of software development, he’s what passes for normal. The question is whether that situation should be allowed to continue.**
|
||||
|
||||
I've known Linus Torvalds, Linux's inventor, for over 20 years. We're not chums, but we like each other.
|
||||
|
||||
Lately, Torvalds has been getting a lot of flack for his management style. Linus doesn't suffer fools gladly. He has one way of judging people in his business of developing the Linux kernel: How good is your code?
|
||||
|
||||
Nothing else matters. As Torvalds said earlier this year at the Linux.conf.au Conference, "I'm not a nice person, and I don't care about you. [I care about the technology and the kernel][1] -- that's what's important to me."
|
||||
|
||||
Now, I can deal with that kind of person. If you can't, you should avoid the Linux kernel community, where you'll find a lot of this kind of meritocratic thinking. Which is not to say that I think everything in Linuxland is hunky-dory and should be impervious to calls for change. A meritocracy I can live with; a bastion of male dominance where women are subjected to scorn and disrespect is a problem.
|
||||
|
||||
That's why I see the recent brouhaha about Torvalds' management style -- or more accurately, his total indifference to the personal side of management -- as nothing more than standard operating procedure in the world of software development. And at the same time, I see another instance that has come to light as evidence of a need for things to really change.
|
||||
|
||||
The first situation arose with the [release of Linux 4.3][2], when Torvalds used the Linux Kernel Mailing List to tear into a developer who had inserted some networking code that Torvalds thought was -- well, let's say "crappy." "[[A]nd it generates [crappy] code.][3] It looks bad, and there's no reason for it." He goes on in this vein for quite a while. Besides the word "crap" and its earthier synonym, he uses the word "idiotic" pretty often.
|
||||
|
||||
Here's the thing, though. He's right. I read the code. It's badly written and it does indeed seem to have been designed to use the new "overflow_usub()" function just for the sake of using it.
|
||||
|
||||
Now, some people see this diatribe as evidence that Torvalds is a bad-tempered bully. I see a perfectionist who, within his field, doesn't put up with crap.
|
||||
|
||||
Many people have told me that this is not how professional programmers should act. People, have you ever worked with top developers? That's exactly how they act, at Apple, Microsoft, Oracle and everywhere else I've known them.
|
||||
|
||||
I've heard Steve Jobs rip a developer to pieces. I've cringed while a senior Oracle developer lead tore into a room of new programmers like a piranha through goldfish.
|
||||
|
||||
In Accidental Empires, his classic book on the rise of PCs, Robert X. Cringely described Microsoft's software management style when Bill Gates was in charge as a system where "Each level, from Gates on down, screams at the next, goading and humiliating them." Ah, yes, that's the Microsoft I knew and hated.
|
||||
|
||||
The difference between the leaders at big proprietary software companies and Torvalds is that he says everything in the open for the whole world to see. The others do it in private conference rooms. I've heard people claim that Torvalds would be fired in their company. Nope. He'd be right where he is now: on top of his programming world.
|
||||
|
||||
Oh, and there's another difference. If you get, say, Larry Ellison mad at you, you can kiss your job goodbye. When you get Torvalds angry at your work, you'll get yelled at in an email. That's it.
|
||||
|
||||
You see, Torvalds isn't anyone's boss. He's the guy in charge of a project with about 10,000 contributors, but he has zero hiring and firing authority. He can hurt your feelings, but that's about it.
|
||||
|
||||
That said, there is a serious problem within both open-source and proprietary software development circles. No matter how good a programmer you are, if you're a woman, the cards are stacked against you.
|
||||
|
||||
No case shows this better than that of Sarah Sharp, an Intel developer and formerly a top Linux programmer. [In a post on her blog in October][4], she explained why she had stopped contributing to the Linux kernel more than a year earlier: "I finally realized that I could no longer contribute to a community where I was technically respected, but I could not ask for personal respect.... I did not want to work professionally with people who were allowed to get away with subtle sexist or homophobic jokes."
|
||||
|
||||
Who can blame her? I can't. Torvalds, like almost every software manager I've ever known, I'm sorry to say, has permitted a hostile work environment.
|
||||
|
||||
He would probably say that it's not his job to ensure that Linux contributors behave with professionalism and mutual respect. He's concerned with the code and nothing but the code.
|
||||
|
||||
As Sharp wrote:
|
||||
|
||||
> I have the utmost respect for the technical efforts of the Linux kernel community. They have scaled and grown a project that is focused on maintaining some of the highest coding standards out there. The focus on technical excellence, in combination with overloaded maintainers, and people with different cultural and social norms, means that Linux kernel maintainers are often blunt, rude, or brutal to get their job done. Top Linux kernel developers often yell at each other in order to correct each other's behavior.
|
||||
>
|
||||
> That's not a communication style that works for me. …
|
||||
>
|
||||
> Many senior Linux kernel developers stand by the right of maintainers to be technically and personally brutal. Even if they are very nice people in person, they do not want to see the Linux kernel communication style change.
|
||||
|
||||
She's right.
|
||||
|
||||
Where I differ from other observers is that I don't think that this problem is in any way unique to Linux or open-source communities. With five years of work in the technology business and 25 years as a technology journalist, I've seen this kind of immature boy behavior everywhere.
|
||||
|
||||
It's not Torvalds' fault. He's a technical leader with a vision, not a manager. The real problem is that there seems to be no one in the software development universe who can set a supportive tone for teams and communities.
|
||||
|
||||
Looking ahead, I hope that companies and organizations, such as the Linux Foundation, can find a way to empower community managers or other managers to encourage and enforce civil behavior.
|
||||
|
||||
We won't, unfortunately, find that kind of managerial finesse in our pure technical or business leaders. It's not in their DNA.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.computerworld.com/article/3004387/it-management/how-bad-a-boss-is-linus-torvalds.html
|
||||
|
||||
作者：[Steven J. Vaughan-Nichols][a]
|
||||
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]:http://www.computerworld.com/author/Steven-J.-Vaughan_Nichols/
|
||||
[1]:http://www.computerworld.com/article/2874475/linus-torvalds-diversity-gaffe-brings-out-the-best-and-worst-of-the-open-source-world.html
|
||||
[2]:http://www.zdnet.com/article/linux-4-3-released-after-linus-torvalds-scraps-brain-damage-code/
|
||||
[3]:http://lkml.iu.edu/hypermail/linux/kernel/1510.3/02866.html
|
||||
[4]:http://sarah.thesharps.us/2015/10/05/closing-a-door/
|
||||
@ -0,0 +1,125 @@
|
||||
Install Android On BQ Aquaris Ubuntu Phone In Linux
|
||||
================================================================================
|
||||
|
||||
|
||||
If you happen to own the first Ubuntu phone and want to **replace Ubuntu with Android on the bq Aquaris e4.5**, this post is going to help you.
|
||||
|
||||
There can be plenty of reasons why you might want to remove Ubuntu and use the mainstream Android OS. One of the foremost reason is that the OS itself is at an early stage and intend to target developers and enthusiasts. Whatever may be your reason, installing Android on bq Aquaris is a piece of cake, thanks to the tools provided by bq.
|
||||
|
||||
Let’s see what to do we need to install Android on bq Aquaris.
|
||||
|
||||
### Prerequisite ###
|
||||
|
||||
- Working Internet connection to download Android factory image and install tools for flashing Android
|
||||
- USB data cable
|
||||
- A system running Linux
|
||||
|
||||
This tutorial is performed using Ubuntu 15.10. But the steps should be applicable to most other Linux distributions.
|
||||
|
||||
### Replace Ubuntu with Android in bq Aquaris e4.5 ###
|
||||
|
||||
#### Step 1: Download Android firmware ####
|
||||
|
||||
First step is to download the Android image for bq Aquaris e4.5. Good thing is that it is available from the bq’s support website. You can download the firmware, around 650 MB in size, from the link below:
|
||||
|
||||
- [Download Android for bq Aquaris e4.5][1]
|
||||
|
||||
Yes, you would get OTA updates with it. At present the firmware version is 2.0.1 which is based on Android Lolipop. Over time, there could be a new firmware based on Marshmallow and then the above link could be outdated.
|
||||
|
||||
I suggest to check the [bq support page][2] and download the latest firmware from there.
|
||||
|
||||
Once downloaded, extract it. In the extracted directory, look for **MT6582_Android_scatter.txt** file. We shall be using it later.
|
||||
|
||||
#### Step 2: Download flash tool ####
|
||||
|
||||
bq has provided its own flash tool, Herramienta MTK Flash Tool, for easier installation of Android or Ubuntu on the device. You can download the tool from the link below:
|
||||
|
||||
- [Download MTK Flash Tool][3]
|
||||
|
||||
Since the flash tool might be upgraded in future, you can always get the latest version of flash tool from the [bq support page][4].
|
||||
|
||||
Once downloaded extract the downloaded file. You should see an executable file named **flash_tool** in it. We shall be using it later.
|
||||
|
||||
#### Step 3: Remove conflicting packages (optional) ####
|
||||
|
||||
If you are using recent version of Ubuntu or Ubuntu based Linux distributions, you may encounter “BROM ERROR : S_UNDEFINED_ERROR (1001)” later in this tutorial.
|
||||
|
||||
To avoid this error, you’ll have to uninstall conflicting package. Use the commands below:
|
||||
|
||||
sudo apt-get remove modemmanager
|
||||
|
||||
Restart udev service with the command below:
|
||||
|
||||
sudo service udev restart
|
||||
|
||||
Just to check for any possible side effects on kernel module cdc_acm, run the command below:
|
||||
|
||||
lsmod | grep cdc_acm
|
||||
|
||||
If the output of the above command is an empty list, you’ll have to reinstall this kernel module:
|
||||
|
||||
sudo modprobe cdc_acm
|
||||
|
||||
#### Step 4: Prepare to flash Android ####
|
||||
|
||||
Go to the downloaded and extracted flash tool directory (in step 2). Use command line for this purpose because you’ll have to use the root privileges here.
|
||||
|
||||
Presuming that you saved it in the Downloads directory, use the command below to go to this directory (in case you do not know how to navigate between directories in command line).
|
||||
|
||||
cd ~/Downloads/SP_Flash*
|
||||
|
||||
After that use the command below to run the flash tool as root:
|
||||
|
||||
sudo ./flash_tool
|
||||
|
||||
You’ll see a window popped as the one below. Don’t bother about Download Agent field, it will be automatically filled. Just focus on Scatter-loading field.
|
||||
|
||||
|
||||
|
||||
Remember we talked about **MT6582_Android_scatter.txt** in step 1? This text file is in the extracted directory of the Andriod firmware you downloaded in step 1. Click on Scatter-loading (in the above picture) and point to MT6582_Android_scatter.txt file.
|
||||
|
||||
When you do that, you’ll see several green lines like the one below:
|
||||
|
||||
|
||||
|
||||
#### Step 5: Flashing Android ####
|
||||
|
||||
We are almost ready. Switch off your phone and connect it to your computer via a USB cable.
|
||||
|
||||
Select Firmware Upgrade from the dropdown and after that click on the big download button.
|
||||
|
||||
|
||||
|
||||
If everything is correct, you should see a flash status in the bottom of the tool:
|
||||
|
||||
|
||||
|
||||
When the procedure is successfully completed, you’ll see a notification like this:
|
||||
|
||||
|
||||
|
||||
Unplug your phone and power it on. You should see a white screen with AQUARIS written in the middle and at bottom, “powered by Android” would be displayed. It might take upto 10 minutes before you could configure and start using Android.
|
||||
|
||||
Note: If something goes wrong in the process, Press power, volume up, volume down button together and boot in to fast boot mode. Turn off again and connect the cable again. Repeat the process of firmware upgrade. It should work.
|
||||
|
||||
### Conclusion ###
|
||||
|
||||
Thanks to the tools provided, it becomes easier to **flash Android on bq Ubuntu Phone**. Of course, you can use the same steps to replace Android with Ubuntu. All you need is to download Ubuntu firmware instead of Android.
|
||||
|
||||
I hope this tutorial helped you to replace Ubuntu with Android on your bq phone. If you have questions or suggestions, feel free to ask in the comment section below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://itsfoss.com/install-android-ubuntu-phone/
|
||||
|
||||
作者：[Abhishek][a]
|
||||
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]:http://itsfoss.com/author/abhishek/
|
||||
[1]:https://storage.googleapis.com/otas/2014/Smartphones/Aquaris_E4.5_L/2.0.1_20150623-1900_bq-FW.zip
|
||||
[2]:http://www.bq.com/gb/support/aquaris-e4-5
|
||||
[3]:https://storage.googleapis.com/otas/2014/Smartphones/Aquaris_E4.5/Ubuntu/Web%20version/Web%20version/SP_Flash_Tool_exe_linux_v5.1424.00.zip
|
||||
[4]:http://www.bq.com/gb/support/aquaris-e4-5-ubuntu-edition
|
||||
171
sources/tech/20151117 Linux 101--Get the most out of Systemd.md
Normal file
171
sources/tech/20151117 Linux 101--Get the most out of Systemd.md
Normal file
@ -0,0 +1,171 @@
|
||||
Linux 101: Get the most out of Systemd
|
||||
================================================================================
|
||||
Why do this?
|
||||
|
||||
- Understand the big changes in modern distros.
|
||||
- See how Systemd replaces SysVinit.
|
||||
- Get to grips with units and the new journal.
|
||||
|
||||
Hate mail, personal insults, death threats – Lennart Poettering, the author of Systemd, is used to receiving these. The Red Hat employee recently ranted on Google+ about the nature of the FOSS community ([http://tinyurl.com/poorlennart][1]), lamenting that it’s “quite a sick place to be in”. In particular, he points to Linus Torvalds’s highly acerbic mailing list posts, and accuses the kernel head honcho of setting the tone of online discussion, making personal attacks and derogatory comments the norm.
|
||||
|
||||
But why has Poettering received so much hate? Why does a man who simply develops open source software have to tolerate this amount of anger? Well, the answer lies in the importance of his software. Systemd is the first thing launched by the Linux kernel on most distributions now, and it serves many roles. It starts system services, handles logins, executes tasks at specified intervals, and much more. It’s growing all the time, and becoming something of a “base system” for Linux – providing all the plumbing tools needed to boot and maintain a distro.
|
||||
|
||||
Now, Systemd is controversial for various reasons: it eschews some established Unix conventions, such as plain text log files. It’s seen as a “monolithic” project trying to take over everything else. And it’s a major change to the underpinnings of our OS. Yet almost every major distribution has adopted it (or is about to), so it’s here to stay. And there are benefits: faster booting, easier management of services that depend on one another, and powerful and secure logging facilities too.
|
||||
|
||||
So in this tutorial we’ll explore Systemd’s features, and show you how to get the most out of them. Even if you’re not a fan of the software right now, hopefully at least you’ll feel more comfortable with it by the end.
|
||||
|
||||
|
||||
|
||||
**This tongue-in-cheek animation at [http://tinyurl.com/m2e7mv8][2] portrays Systemd as a rabid animal eating everything in its path. Most critics haven’t been so fluffy.**
|
||||
|
||||
### Booting and services ###
|
||||
|
||||
Almost every major distro has either adopted Systemd, or will do so in the next release (Debian and Ubuntu). In this tutorial we’re using a pre-release of Fedora 21 – a distro that has been a great testing ground for Systemd – but the commands and notes should be the same regardless of your distro. That’s one of the plus points of Systemd: it obviates many of the tiny, niggling differences between distros.
|
||||
|
||||
In a terminal, enter **ps ax | grep systemd** and look at the first line. The **1** means that it’s process ID 1, ie the first thing launched by the Linux kernel. So, once the kernel has done its work detecting hardware and organising memory, it launches the **/usr/lib/systemd/systemd** executable, which then launches other programs in turn. (In pre-Systemd days, the kernel would launch **/sbin/init**, which would then launch various other essential boot scripts, in a system known as SysVinit.)
|
||||
|
||||
Central to Systemd is the concept of units. These are configuration files with information about services (programs running in the background), devices, mount points, timers and other aspects of the operating system. One of Systemd’s goals is to ease and simplify the interaction between these, so if you have a certain program that needs to start when a certain mount point is created when a certain device gets plugged in, it should be considerably easier to make all this work. (In pre-Systemd days, hacking all this together with scripts could get very ugly.) To list all units on your Linux installation, enter:
|
||||
|
||||
systemctl list-unit-files
|
||||
|
||||
Now, **systemctl** is the main tool for interacting with Systemd, and it has many options. Here, in the unit list, you’ll notice that there’s some formatting: enabled units are shown in green, and disabled are shown in red. Units marked as “static” can’t be started directly – they’re dependencies of other units. To narrow down the list to just services, use:
|
||||
|
||||
systemctl list-unit-files --type=service
|
||||
|
||||
Note that “enabled” doesn’t necessarily mean that a service is running; just that it can be turned on. To get information about a specific service, for instance GDM (the Gnome Display Manager), enter:
|
||||
|
||||
systemctl status gdm.service
|
||||
|
||||
This provides lots of useful information: a human-readable description of the service, the location of the unit configuration file, when it was started, its PID, and the CGroups to which it belongs (these limit resource consumption for groups of processes).
|
||||
|
||||
If you look at the unit config file in **/usr/lib/systemd/system/gdm.service**, you’ll see various options, including the binary to be started (ExecStart), what it conflicts with (ie which units can’t be active at the same time), and what needs to be started before this unit can be activated (the “After” line). Some units have additional dependency options, such as “Requires” (mandatory dependencies) and “Wants” (optional).
|
||||
|
||||
Another interesting option here is:
|
||||
|
||||
Alias=display-manager.service
|
||||
|
||||
When you activate **gdm.service**, you will also be able to view its status using **systemctl status display-manager.service**. This is useful when you know there’s a display manager running, and you want to do something with it, but you don’t care whether it’s GDM, KDM, XDM or any of the others.
|
||||
|
||||
|
||||
|
||||
**Use systemctl status, followed by a unit name, to see what’s going on with a service.**
|
||||
|
||||
### Target locked ###
|
||||
|
||||
If you enter **ls** in the **/usr/lib/systemd/system** directory, you’ll also see various files that end in **.target**. A target is a way of grouping units together so that they’re started at the same time. For instance, in most Unix-like OSes there’s a state of the system called “multi-user”, which means that the system has booted correctly, background services are running, and it’s ready for one or more users to log in and do their work – at least, in text mode. (Other states include single-user, for doing administration work, or reboot, for when the machine is shutting down.)
|
||||
|
||||
If you look inside **multi-user.target**, you may be expecting to see a list of units that should be active in this state. But you’ll notice that the file is pretty bare – instead, individual services make themselves dependencies of the target via the **WantedBy** option. So if you look inside **avahi-daemon.service**, **NetworkManager.service** and many other **.service** files, you’ll see this line in the Install section:
|
||||
|
||||
WantedBy=multi-user.target
|
||||
|
||||
So, switching to the multi-user target will enable those units that contain the above line. Other targets are available (such as **emergency.target** for an emergency shell, or **halt.target** for when the machine shuts down), and you can easily switch between them like so:
|
||||
|
||||
systemctl isolate emergency.target
|
||||
|
||||
In many ways, these are like SysVinit runlevels, with text-mode **multi-user.target** being runlevel 3, **graphical.target** being runlevel 5, **reboot.target** being runlevel 6, and so forth.
|
||||
|
||||
|
||||
|
||||
**The unit configuration files might look foreign compared to traditional scripts, but they’re not hard to grasp.**
|
||||
|
||||
### Up and down ###
|
||||
|
||||
Now, you might be pondering: we’ve got this far, and yet we haven’t even looked at stopping and starting services yet! But there’s a reason for this. Systemd can look like a complicated beast from the outside, so it’s good to have an overview of how it works before you start interacting with it. The actual commands for managing services are very simple:
|
||||
|
||||
systemctl stop cups.service
|
||||
systemctl start cups.service
|
||||
|
||||
(If a unit has been disabled, you can first enable it with **systemctl enable** followed by the unit name. This places a symbolic link for the unit in the .wants directory of the current target, in the **/etc/systemd/system** folder.)
|
||||
|
||||
Two more useful commands are **systemctl restart** and **systemctl reload**, followed by unit names. The second asks the unit to reload its configuration file. Systemd is – for the most part – very well documented, so look at the manual page (**man systemctl**) for details on every command.
|
||||
|
||||
> ### Timer units: replacing Cron ###
|
||||
>
|
||||
> Beyond system initialisation and service management, Systemd has its fingers in various other pies too. Notably, it can perform the job of **cron**, arguably with more flexibility (and an easier to read syntax). **Cron** is the program that performs jobs at regular intervals – such as cleaning up temporary files, refreshing caches and so forth.
|
||||
>
|
||||
> If you look inside the **/usr/lib/systemd/system** directory again, you’ll see that various **.timer** files are provided. Have a look at some of them with **less**, and you’ll note that they follow a similar structure to the **.service** and **.target** files. The difference, however, lies in the **[Timer]** section. Consider this example:
|
||||
>
|
||||
> [Timer]
|
||||
> OnBootSec=1h
|
||||
> OnUnitActiveSec=1w
|
||||
>
|
||||
> Here, the **OnBootSec** option tells Systemd to activate the unit 1 hour after the system has booted. Then the second option means: activate the unit once a week after that. There’s a huge amount of flexibility in the times that you can set – enter **man systemd.time** for a full list.
|
||||
>
|
||||
> By default, Systemd’s accuracy for timing is one minute. In other words, it will activate the unit within a minute of the time you specify, but not necessarily to the exact second. This is done for power management reasons, but if you need a timer to be executed without any delay, right down to the microsecond, you can add this line:
|
||||
>
|
||||
> AccuracySec=1us
|
||||
>
|
||||
> Also, the **WakeSystem** option (which can be set to true or false) defines whether or not the timer should wake up the machine if it’s in suspend mode.
|
||||
|
||||
|
||||
|
||||
**A Systemd GUI exists,although it hasn’t been actively worked on for a couple of years.**
|
||||
|
||||
### Log files: say hello to journald ###
|
||||
|
||||
The second major component of Systemd is the journal. This is a logging system, similar to syslog, but with some major differences. And if you’re a fan of the Unix way, prepare for your blood to boil: it’s a binary log, so you can’t just parse it using your regular command line text tools. This design decision regularly whips up heated debates on the net, but it has some benefits too. For instance, logs can be more structured, with better metadata, so it’s easier to filter out information based on executable name, PID, time and so forth.
|
||||
|
||||
To view the journal in its entirety, enter:
|
||||
|
||||
journalctl
|
||||
|
||||
As with many other Systemd commands, this pipes the output into the **less** program, so you can scroll down by hitting space, use / (forward slash) to search, and other familiar keybindings. You’ll also notice a sprinkling of colour here too, with warnings and failure messages in red.
|
||||
|
||||
That’s a lot of information; to narrow it down to the current boot, use:
|
||||
|
||||
journalctl -b
|
||||
|
||||
And here’s where the Systemd journal starts to shine. Do you want to see all messages from the previous boot? Try **journalctl -b -1**. Or the one before that? Replace **-1** with **-2**. How about something very specific, like all messages from 24 October 2014, 16:38 onwards?”
|
||||
|
||||
journalctl -b --since=”2014-10-24 16:38”
|
||||
|
||||
Even if you deplore binary logs, that’s still a useful feature, and for many admins it’s much easier than constructing a similar filter from regular expressions.
|
||||
|
||||
So we’ve narrowed down the log to specific times, but what about specific programs? For units, try this:
|
||||
|
||||
journalctl -u gdm.service
|
||||
|
||||
(Note: that’s a good way to see the log generated by the X server.) Or how about a specific PID?
|
||||
|
||||
journalctl _PID=890
|
||||
|
||||
You can even request to just see messages from a certain executable:
|
||||
|
||||
journalctl /usr/bin/pulseaudio
|
||||
|
||||
If you want to narrow down to messages of a certain priority, use the **-p** option. With 0 this will only show emergency messages (ie it’s time to start praying to **$DEITY**), whereas 7 will show absolutely everything, including debugging messages. See the manual page (**man journalctl**) for more details on the priority levels.
|
||||
|
||||
It’s worth noting that you can combine options as well, so to only show messages from the GDM service of priority level 3 (or lower) from the current boot, use:
|
||||
|
||||
journalctl -u gdm.service -p 3 -b
|
||||
|
||||
Finally, if you just want to have a terminal window open, constantly updating with the latest journal entries, as you’d have with the tail command in pre-Systemd installations, just enter **journalctl -f**.
|
||||
|
||||
|
||||
|
||||
**Binary logging isn’t popular, but the journal has some benefits, like very easy filtering of information.**
|
||||
|
||||
> ### Life without Systemd? ###
|
||||
>
|
||||
> If you simply, absolutely can’t get on with Systemd, you still have a few choices among the major distributions. Most notably, Slackware, the longest-running distro, hasn’t made the switch yet – but its lead developer hasn’t ruled it out for the future. A few small-name distros are also holding out with SysVinit as well.
|
||||
>
|
||||
> But how long will this last? Gnome is becoming increasingly dependent on Systemd, and the other major desktop environments could follow suit. This is a cause of consternation in the BSD communities, as Systemd is heavily tied to Linux kernel features, so the desktops are becoming less portable, in a way. A half-way-house solution might arrive in the form of Uselessd ([http://uselessd.darknedgy.net][3]), which is a stripped-down version of Systemd that purely focuses on launching and supervising processes, without consuming the whole base system.
|
||||
>
|
||||
> 
|
||||
>
|
||||
> If you don’t like Sysytemd, try Gentoo, which has it as a choice of init system, but doesn’t force it on its users.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.linuxvoice.com/linux-101-get-the-most-out-of-systemd/
|
||||
|
||||
作者：[Mike Saunders][a]
|
||||
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]:http://www.linuxvoice.com/author/mike/
|
||||
[1]:http://tinyurl.com/poorlennart
|
||||
[2]:http://tinyurl.com/m2e7mv8
|
||||
[3]:http://uselessd.darknedgy.net/
|
||||
@ -0,0 +1,43 @@
|
||||
sevenot translated
|
||||
好奇Linux？试试云端的Linux桌面
|
||||
================================================================================
|
||||
Linux在桌面操作系统市场上只占据了非常小的份额，目前调查来看，估计只有2%的市场份额；对比来看丰富多变的Windows系统占据了接近90%的市场份额。对于Linux来说要挑战Windows在桌面操作系统市场的垄断，需要一个简单的方式来让用户学习不同的操作系统。如果你相信传统的Windows用户再买一台机器来使用Linux，你就太天真了。我们只能去试想用户重新分盘，设置引导程序来使用双系统，或者跳过所有步骤回到一个最简单的方法。
|
||||
|
||||
|
||||
我们实验过一系列无风险的使用方法让用户试操作Linux，并且不涉及任何分区管理，包括CD/DVDs光盘、USB钥匙和桌面虚拟化软件。通过实验，我强烈推荐使用VMware的VMware Player或者Oracle VirtualBox虚拟机，对于桌面操作系统或者便携式电脑的用户，这是一种相对简单而且免费的的方法来安装运行多操作系统。每一台虚拟机和其他虚拟机相隔离，但是共享CPU,存贮，网络接口等等。但是虚拟机仍需要一定的资源来安装运行Linux，也需要一台相当强劲的主机。对于一个好奇心不大的人，这样做实在是太麻烦了。
|
||||
|
||||
要打破用户传统的使用观念市非常困难的。很多Windows用户可以尝试使用Linux提供的免费软件，但也有太多要学习的Linux系统知识。这会花掉相当一部分时间来习惯Linux的工作方式。
|
||||
|
||||
当然了，对于一个第一次在Linux上操作的新手，有没有一个更高效的方法呢？答案是肯定的，接着往下看看云实验平台。
|
||||
|
||||
### LabxNow ###
|
||||
|
||||
|
||||
|
||||
LabxNow提供了一个免费服务，方便广大用户通过浏览器来访问远程Liunx桌面。开发者将其加强为一个用户个人远程实验室（用户可以在系统里运行、开发任何程序），用户可以在任何地方通过互联网登入远程实验室。
|
||||
|
||||
这项服务现在可以为个人用户提供2核处理器，4GB RAM和10GB的固态硬盘，运行在128G RAM的4 AMD 6272处理器上。
|
||||
|
||||
#### 配置参数: ####
|
||||
|
||||
- 系统镜像：基于Ubuntu 14.04的Xface 4.10，RHEL 6.5,CentOS(Gnome桌面)，Oracle
|
||||
- 硬件: CPU - 1核或者2核; 内存: 512MB, 1GB, 2GB or 4GB
|
||||
- 超快的网络数据传输
|
||||
- 可以运行在所有流行的浏览器上
|
||||
- 可以安装任意程序，可以运行任何程序 – 这是一个非常棒的方法，可以随意做实验学你你想学的所有知识， 没有 一点风险
|
||||
- 添加、删除、管理、制定虚拟机非常方便
|
||||
- 支持虚拟机共享，远程桌面
|
||||
|
||||
你所需要的只是一台有稳定网络的设备。不用担心虚拟专用系统（VPS）、域名、或者硬件带来的高费用。LabxNow提供了一个非常好的方法在Ubuntu、RHEL和CentOS上实验。它给Windows用户一个极好的环境，让他们探索美妙的Linux世界。说得深一点，它可以让用户随时随地在里面工作，而没有了要在每台设备上安装Linux的压力。点击下面这个链接进入[www.labxnow.org/labxweb/][1]。
|
||||
|
||||
这里还有一些其它服务(大部分市收费服务)可以让用户在Linux使用。包括Cloudsigma环境的7天使用权和Icebergs.io(通过HTML5实现root权限)。但是现在，我推荐LabxNow。
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
来自: http://www.linuxlinks.com/article/20151003095334682/LinuxCloud.html
|
||||
|
||||
译者：[sevenot](https://github.com/sevenot)
|
||||
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
|
||||
|
||||
[1]:https://www.labxnow.org/labxweb/
|
||||
@ -1,128 +0,0 @@
|
||||
开发者的 Linux 容器之旅
|
||||
================================================================================
|
||||
|
||||
|
||||
我告诉你一个秘密：使得我的应用程序进入到全世界的所有云计算的东西，对我来说仍然有一点神秘。但随着时间流逝，我意识到理解大规模机器配置和应用程序部署的来龙去脉对一个开发者来说是非常重要的知识。这类似于成为一个专业的音乐家。你当然需要知道如何使用你的乐器。但是，如果你不知道一个录音室是如何工作的，或者你如何适应一个交响乐团，你在这样的环境中工作会变得非常困难。
|
||||
|
||||
在软件开发的世界里，使你的代码进入我们更大的世界正如写出它来一样重要。开发重要，而且是很重要。
|
||||
|
||||
因此，为了弥合开发和部署之间的间隔，我会从头开始介绍容器技术。为什么是容器？因为有强有力的证据表明，容器是机器抽象的下一步：使计算机成为场所而不再是一个东西。理解容器是我们共同的旅程。
|
||||
|
||||
在这篇文章中，我会介绍容器化背后的概念。容器和虚拟机的区别。以及容器构建背后的逻辑以及它是如何适应应用程序架构的。我会探讨轻量级的 Linux 操作系统是如何适应容器生态系统。我还会讨论使用镜像创建可重用的容器。最后我会介绍容器集群如何使你的应用程序可以快速扩展。
|
||||
|
||||
在后面的文章中，我会一步一步向你介绍容器化一个事例应用程序的过程，以及如何为你的应用程序容器创建一个托管集群。同时，我会向你展示如何使用 Deis 将你的事例应用程序部署到你本地系统以及多种云供应商的虚拟机上。
|
||||
|
||||
让我们开始吧。
|
||||
|
||||
### 虚拟机的好处 ###
|
||||
|
||||
为了理解容器如何适应事物发展，你首先要了解容器的前者：虚拟机
|
||||
|
||||
[虚拟机][1] 是运行在物理宿主机上的软件抽象。配置一个虚拟机就像是购买一台计算机：你需要定义你想要的 CPU 数目，RAM 和磁盘存储容量。配置好了机器后，你把它加载到操作系统，然后是你想让虚拟机支持的任何服务器或者应用程序。
|
||||
|
||||
虚拟机允许你在一台硬件主机上运行多个模拟计算机。这是一个简单的示意图：
|
||||
|
||||
|
||||
|
||||
虚拟机使得能充分利用你的硬件资源。你可以购买一台大型机然后在上面运行多个虚拟机。你可以有一个数据库虚拟机以及很多运行相同版本定制应用程序的虚拟机构成的集群。你可以在有限的硬件资源获得很多的扩展能力。如果你觉得你需要更多的虚拟机而且你的宿主硬件还有容量，你可以添加任何你想要的。或者，如果你不再需要一个虚拟机，你可以关闭该虚拟机并删除虚拟机镜像。
|
||||
|
||||
### 虚拟机的局限 ###
|
||||
|
||||
但是，虚拟机确实有局限。
|
||||
|
||||
如上面所示，假如你在一个主机上创建了三个虚拟机。主机有 12 个 CPU，48 GB 内存和 3TB 的存储空间。每个虚拟机配置为有 4 个 CPU，16 GB 内存和 1TB 存储空间。到现在为止，一切都还好。主机有这个容量。
|
||||
|
||||
但这里有个缺陷。所有分配给一个虚拟机的资源，无论是什么，都是专有的。每台机器都分配了 16 GB 的内存。但是，如果第一个虚拟机永不会使用超过 1GB 分配的内存，剩余的 15 GB 就会被浪费在那里。如果第三天虚拟机只使用分配的 1TB 存储空间中的 100GB，其余的 900GB 就成为浪费空间。
|
||||
|
||||
这里没有资源的流动。每台虚拟机拥有分配给它的所有资源。因此，在某种方式上我们又回到了虚拟机之前，把大部分金钱花费在未使用的资源上。
|
||||
|
||||
虚拟机还有*另一个*缺陷。扩展他们需要很长时间。如果你处于基础设施需要快速增长的情形，即使虚拟机配置是自动的，你仍然会发现你的很多时间都浪费在等待机器上线。
|
||||
|
||||
### 来到：容器 ###
|
||||
|
||||
概念上来说，容器是 Linux 中认为只有它自己的一个进程。该进程只知道告诉它的东西。另外，在容器化方面，该容器进程也分配了它自己的 IP 地址。这点很重要，我会再次重复。**在容器化方面，容器进程有它自己的 IP 地址**。一旦给予了一个 IP 地址，该进程就是宿主网络中可识别的资源。然后，你可以在容器管理器上运行命令，使容器 IP 映射到主机中能访问公网的 IP 地址。该映射发生时，对于任何意图和目的，一个容器就是网络上一个可访问的独立机器，概念上类似于虚拟机。
|
||||
|
||||
再次说明，容器是拥有不同 IP 地址从而使其成为网络上可识别的独立 Linux 进程。下面是一个示意图：
|
||||
|
||||
|
||||
|
||||
容器/进程以动态合作的方式共享主机上的资源。如果容器只需要 1GB 内存，它就只会使用 1GB。如果它需要 4GB，就会使用 4GB。CPU 和存储空间利用也是如此。CPU，内存和存储空间的分配是动态的，和典型虚拟机的静态方式不同。所有这些资源的共享都由容器管理器管理。
|
||||
|
||||
最后，容器能快速启动。
|
||||
|
||||
因此，容器的好处是：**你获得了虚拟机独立和封装的好处而抛弃了专有静态资源的缺陷**。另外，由于容器能快速加载到内存，在扩展到多个容器时你能获得更好的性能。
|
||||
|
||||
### 容器托管、配置和管理 ###
|
||||
|
||||
托管容器的计算机运行着被剥离的只剩下主要部分的 Linux 版本。现在，宿主计算机流行的底层操作系统是上面提到的 [CoreOS][2]。当然还有其它，例如 [Red Hat Atomic Host][3] 和 [Ubuntu Snappy][4]。
|
||||
|
||||
所有容器之间共享Linux 操作系统，减少了容器足迹的重复和冗余。每个容器只包括该容器唯一的部分。下面是一个示意图：
|
||||
|
||||
|
||||
|
||||
你用它所需的组件配置容器。一个容器组件被称为**层**。一层是一个容器镜像，（你会在后面的部分看到更多关于容器镜像的介绍）。你从一个基本层开始，这通常是你想在容器中使用的操作系统。（容器管理器只提供你想要的操作系统在宿主操作系统中不存在的部分。）当你构建配置你的容器时，你会添加层，例如你想要添加网络服务器 Apache，如果容器要运行脚本，则需要添加 PHP 或 Python 运行时。
|
||||
|
||||
分层非常灵活。如果应用程序或者服务容器需要 PHP 5.2 版本，你相应地配置该容器即可。如果你有另一个应用程序或者服务需要 PHP 5.6 版本，没问题，你可以使用 PHP 5.6 配置该容器。不像虚拟机，更改一个版本的运行时依赖时你需要经过大量的配置和安装过程；对于容器你只需要在容器配置文件中重新定义层。
|
||||
|
||||
所有上面描述的容器多功能性都由一个称为容器管理器的软件控制。现在，最流行的容器管理器是 [Docker][5] 和 [Rocket][6]。上面的示意图展示了容器管理器是 Docker，宿主操作系统是 CentOS 的主机情景。
|
||||
|
||||
### 容器由镜像构成 ###
|
||||
|
||||
当你需要将我们的应用程序构建到容器时，你就会编译镜像。镜像代表了需要完成容器工作的容器模板。（容器里的容器）。镜像被保存在网络上的注册表里。
|
||||
|
||||
从概念上讲，注册表类似于一个使用 Java 的人眼中的 [Maven][7] 仓库，使用 .NET 的人眼中的 [NuGet][8] 服务器。你会创建一个列出了你应用程序所需镜像的容器配置文件。然后你使用容器管理器创建一个包括了你应用程序代码以及从注册表中下载的构成资源的容器。例如，如果你的应用程序包括了一些 PHP 文件，你的容器配置文件会声明你会从注册表中获取 PHP 运行时。另外，你还要使用容器配置文件声明需要复制到容器文件系统中的 .php 文件。容器管理器会封装你应用程序的所有东西为一个独立容器。该容器将会在容器管理器的管理下运行在宿主计算机上。
|
||||
|
||||
这是一个容器创建背后概念的示意图：
|
||||
|
||||
|
||||
|
||||
让我们仔细看看这个示意图。
|
||||
|
||||
（1）表示一个定义了你容器所需东西以及你容器如何构建的容器配置文件。当你在主机上运行容器时，容器管理器会读取配置文件从云上的注册表中获取你需要的容器镜像，（2）作为层将镜像添加到你的容器。
|
||||
|
||||
另外，如果组成镜像需要其它镜像，容器管理器也会获取这些镜像并把它们作为层添加进来。（3）容器管理器会将需要的文件复制到容器中。
|
||||
|
||||
如果你使用了配置服务，例如 [Deis][9]，你刚刚创建的应用程序容器作为镜像存在（4）配置服务会将它部署到你选择的云供应商上。类似 AWS 和 Rackspace 云供应商。
|
||||
|
||||
### 集群中的容器 ###
|
||||
|
||||
好了。这里有一个很好的例子说明了容器比虚拟机提供了更好的配置灵活性和资源利用率。但是，这并不是全部。
|
||||
|
||||
容器真正灵活是在集群中。记住，每个容器有一个独立的 IP 地址。因此，能把它放到负载均衡器后面。将容器放到负载均衡器后面，就上升了一个层次。
|
||||
|
||||
你可以在一个负载均衡容器后运行容器集群以获得更高的性能和高可用计算。这是一个例子：
|
||||
|
||||
|
||||
|
||||
假如你开发了一个进行资源密集型工作的应用程序。例如图片处理。使用类似 [Deis][9] 的容器配置技术，你可以创建一个包括了你图片处理程序以及你图片处理程序需要的所有资源的容器镜像。然后，你可以部署一个或多个容器镜像到主机上的负载均衡器。一旦创建了容器镜像，你可以在系统快要刷爆时把它放到一边，为了满足手中的工作时添加更多的容器实例。
|
||||
|
||||
这里还有更多好消息。你不需要每次添加实例到环境中时手动配置负载均衡器以便接受你的容器镜像。你可以使用服务发现技术告知均衡器你容器的可用性。然后，一旦获知，均衡器就会将流量分发到新的结点。
|
||||
|
||||
### 全部放在一起 ###
|
||||
|
||||
容器技术完善了虚拟机不包括的部分。类似 CoreOS、RHEL Atomic、和 Ubuntu 的 Snappy 宿主操作系统，和类似 Docker 和 Rocket 的容器管理技术结合起来，使得容器变得日益流行。
|
||||
|
||||
尽管容器变得更加越来越普遍，掌握它们还是需要一段时间。但是，一旦你懂得了它们的窍门，你可以使用类似 [Deis][9] 的配置技术使容器创建和部署变得更加简单。
|
||||
|
||||
概念上理解容器和进一步实际使用它们完成工作一样重要。但我认为不实际动手把想法付诸实践，概念也难以理解。因此，我们该系列的下一阶段就是：创建一些容器。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://deis.com/blog/2015/developer-journey-linux-containers
|
||||
|
||||
作者：[Bob Reselman][a]
|
||||
译者：[ictlyh](http://www.mutouxiaogui.cn/blog/)
|
||||
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://deis.com/blog
|
||||
[1]:https://en.wikipedia.org/wiki/Virtual_machine
|
||||
[2]:https://coreos.com/using-coreos/
|
||||
[3]:http://www.projectatomic.io/
|
||||
[4]:https://developer.ubuntu.com/en/snappy/
|
||||
[5]:https://www.docker.com/
|
||||
[6]:https://coreos.com/blog/rocket/
|
||||
[7]:https://en.wikipedia.org/wiki/Apache_Maven
|
||||
[8]:https://www.nuget.org/
|
||||
[9]:http://deis.com/learn
|
||||
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Reference in New Issue
Block a user