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20150323 Papyrus--An Open Source Note Manager.md20150323 Red Hat Developer Toolset 3.1 beta arrives.md20150323 Square 2.0 Icon Pack Is Twice More Beautiful.md
tech
20150323 How to enable ssh login without entering password.md20150323 How to set up networking between Docker containers.md20150323 Linux FAQs with Answers--How to compress JPEG images from the command line on Linux.md20150323 Linux FAQs with Answers--How to install and access CentOS remote desktop on VPS.md
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Papyrus: An Open Source Note Manager
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================================================================================
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In last post, we saw an [open source to-do app Go For It!][1]. In a similar article, today we’ll see an **open source note taking application Papyrus**.
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[Papyrus][2] is a fork of [Kaqaz note manager][3] and is built on QT5. It brings a clean, polished user interface and is security focused (as it claims). Emphasizing on simplicity, I find Papyrus similar to OneNote. You organize your notes in ‘paper’ and add them a label for grouping those papers. Simple enough!
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### Papyrus features: ###
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Though Papyrus focuses on simplicity, it still has plenty of features up its sleeves. Some of the main features are:
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- Note management with labels and categories
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- Advanced search options
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- Touch mode available
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- Full screen option
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- Back up to Dropbox/hard drive/external
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- Password protection for selective papers
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- Sharing papers with other applications
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- Encrypted synchronization via Dropbox
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- Available for Android, Windows and OS X apart from Linux
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### Install Papyrus ###
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Papyrus has APK available for Android users. There are installer files for Windows and OS X. Linux users can get source code of the application. Ubuntu and other Ubuntu based distributions can use the .deb packages. Based on your OS and preference, you can get the respective files from the Papyrus download page:
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- [Download Papyrus][4]
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### Screenshots ###
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Here are some screenshots of the application:
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Give Papyrus a try and see if you like it. Do share your experience with it with the rest of us here.
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--------------------------------------------------------------------------------
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via: http://itsfoss.com/papyrus-open-source-note-manager/
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作者：[Abhishek][a]
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译者：[译者ID](https://github.com/译者ID)
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校对：[校对者ID](https://github.com/校对者ID)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
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[a]:http://itsfoss.com/author/abhishek/
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[1]:http://itsfoss.com/go-for-it-to-do-app-in-linux/
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[2]:http://aseman.co/en/products/papyrus/
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[3]:https://github.com/sialan-labs/kaqaz/
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[4]:http://aseman.co/en/products/papyrus/
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Red Hat Developer Toolset 3.1 beta arrives
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================================================================================
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> **Summary**:Want the newest developer tools for Red Hat Enterprise Linux 6 or 7? The beta's ready for you now.
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It's one of those eternal problems between developers and operators that even [DevOps][1] can't entirely solve. System administrators want the most stable operating system possible, while programmers want the latest and greatest development tools. [Red Hat][2]'s solution for this dilemma has been to take those brand spanking-new tools, test them out on the latest stable [Red Hat Enterprise Linux (RHEL)][3], and then release them to developers.
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Red Hat Developer Toolset
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So it is that Red Hat has just announced its latest toys for developers, [Red Hat Developer Toolset 3.1][4]. This packaging of the hottest new tools is now available in beta.
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This update includes:
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[GNUCompiler Collection (GCC) 4.9][5]: the latest stable upstream version of GCC, which provides numerous improvements and bug fixes
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[Eclipse 4.4.1][6]: with support for Java 8 and updated versions of Eclipse CDT (8.5), Eclipse Linux Tools (3.1), Eclipse Mylyn (3.14), and Eclipse Egit/Jgit (3.6.1)
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Numerous additional updated packages: These include GDB 7.8.2, elfutils 0.161, memstomp 0.1.5, SystemTap 2.6, Valgrind 3.10.1, Dyninst 8.2.1, and ltrace 0.7.91.
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With these development programs, you'll be able to create applications for RHEL 6 and 7.x. These apps will then run on RHEL regardless of whether you're running it on a physical, virtual or cloud environments. They will also run on Red Hat's [OpenShift][7], its Platform-as-a-Service (PaaS) offering.
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This new set of developer programs includes packages for both RHEL 7 and 7 running on [AMD64 and Intel 64 architectures][8]. Although the tools are 64-bit you can use them to create and modify 32-bit binaries.
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Before you try running any of these programs, you should patch RHEL with all the latest updates. To install the beta Toolset, your systems need to be subscribed to the Optional channel to access all the required Red Hat Developer Toolset tool-chain packages.
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In addition, if you've installed earlier Toolkits you may run into some [problems while installing Toolkit 3.1][9]. While these difficulties are easy enough to fix, you should go over these possible hiccups before trying to install the new Toolkit.
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Finally, you may notice that some of the most exciting of the new tools, such as Docker, Kubernetes, and other container tools aren't here. That's because they're in the newly released [RHEL 7.1][10] and [Red Hat Enterprise Linux 7 Atomic Host (RHELAH)][11]. [Red Hat has partnered with Docker][12], but you'll need to move to a Docker-friendly version of RHEL to get at these container-friendly programs.
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--------------------------------------------------------------------------------
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via: http://www.zdnet.com/article/red-hat-developer-toolset-3-1-beta-arrives/
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作者：[Steven J. Vaughan-Nichols][a]
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译者：[译者ID](https://github.com/译者ID)
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校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
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|
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[a]:http://www.zdnet.com/meet-the-team/us/sjvn/
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[1]:http://blogs.csc.com/2015/02/03/devops-theory-for-beginners/
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[2]:http://www.redhat.com/en
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[3]:http://www.redhat.com/en/technologies/linux-platforms/enterprise-linux
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[4]:http://www.redhat.com/en/about/blog/red-hat-developer-toolset-31-beta-now-available
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[5]:https://gcc.gnu.org/gcc-4.9/
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[6]:https://projects.eclipse.org/projects/eclipse/releases/4.4.1
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[7]:https://www.openshift.com/
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[8]:https://access.redhat.com/documentation/en-US/Red_Hat_Developer_Toolset/3-Beta/html/3.1_Release_Notes/System_Requirements.html
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[9]:https://access.redhat.com/documentation/en-US/Red_Hat_Developer_Toolset/3-Beta/html/3.1_Release_Notes/DTS3.1_Release.html#Known_Issues
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[10]:http://www.zdnet.com/article/red-hat-7-1-is-here-centos-7-1-is-coming-soon/
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[11]:http://www.zdnet.com/article/red-hat-buys-into-docker-containers-with-atomic-host/
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[12]:http://www.zdnet.com/article/red-hat-partners-with-docker-to-create-linuxdocker-software-stack/
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Square 2.0 Icon Pack Is Twice More Beautiful
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================================================================================
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Elegant, modern looking [Square icon theme][1] has recently been upgraded to version 2.0, which makes it more beautiful than ever. Square icon packs are compatible with all major desktop environments such as **Unity, GNOME, KDE, MATE** etc. Which means that you can use them for all popular Linux distributions such as Ubuntu, Fedora, Linux Mint, elementary OS etc. The vastness of this icon pack can be estimated from the fact it contains over 15,000 icons.
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### Install and use Square icon pack 2.0 in Linux ###
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There are two variants of Square icons, dark and light. Based on your preference, you can choose either of the two. For experimentation sake, I would advise you to download both variants of the icon theme.
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You can download the icon pack from the link below. The files are stored in Google Drive, so don’t be suspicious if you don’t see a standard website like [SourceForge][2].
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- [Square Dark Icons][3]
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- [Square Light Icons][4]
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To use the icon theme, extract the downloaded files in ~/.icons directory. If this doesn’t exist, create it. Once you have the files in the right place, based on your desktop environment, use a tool to change the icon theme. I have written some small tutorials in the past on this topic. Feel free to refer to them if you need further help:
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- [How to change themes in Ubuntu Unity][5]
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- [How to change themes in GNOME Shell][6]
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- [How to change themes in Linux Mint][7]
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- [How to change theme in Elementary OS Freya][8]
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### Give it a try ###
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Here is what my Ubuntu 14.04 looks like with Square icons. I am using [Ubuntu 15.04 default wallpaper][9] in the background.
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A quick look at several icons in the Square theme:
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How do you find it? Do you think it can be considered as one of the [best icon themes for Ubuntu 14.04][10]? Do share your thoughts and stay tuned for more articles on customizing your Linux desktop.
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--------------------------------------------------------------------------------
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via: http://itsfoss.com/square-2-0-icon-pack-linux/
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作者：[Abhishek][a]
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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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://itsfoss.com/author/abhishek/
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[1]:http://gnome-look.org/content/show.php/Square?content=163513
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[2]:http://sourceforge.net/
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[3]:http://gnome-look.org/content/download.php?content=163513&id=1&tan=62806435
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[4]:http://gnome-look.org/content/download.php?content=163513&id=2&tan=19789941
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[5]:http://itsfoss.com/how-to-install-themes-in-ubuntu-13-10/
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[6]:http://itsfoss.com/install-switch-themes-gnome-shell/
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[7]:http://itsfoss.com/install-icon-linux-mint/
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[8]:http://itsfoss.com/install-themes-icons-elementary-os-freya/
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[9]:http://itsfoss.com/default-wallpapers-ubuntu-1504/
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[10]:http://itsfoss.com/best-icon-themes-ubuntu-1404/
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How to enable ssh login without entering password
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================================================================================
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Assume that you are a user "aliceA" on hostA, and wish to ssh to hostB as user "aliceB", without entering her password on hostB. You can follow this guide to **enable ssh login without entering a password**.
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First of all, you need to be logged in as user "aliceA" on hostA.
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Generate a public/private rsa key pair by using ssh-keygen. The generated key pair will be stored in ~/.ssh directory.
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$ ssh-keygen -t rsa
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Then, create ~/.ssh directory on aliceB account at the destination hostB by running the following command. This step can be omitted if there is already .ssh directory at aliceB@hostB.
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$ ssh aliceB@hostB mkdir -p .ssh
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Finally, copy the public key of user "aliceA" on hostA to aliceB@hostB to enable password-less ssh.
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$ cat .ssh/id_rsa.pub | ssh aliceB@hostB 'cat >> .ssh/authorized_keys'
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From this point on, you no longer need to type in password to ssh to aliceB@hostB from aliceA@hostA.
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### Troubleshooting ###
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1. You are still asked for an SSH password even after enabling key authentication. In this case, check for system logs (e.g., /var/log/secure) to see if you see something like the following.
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Authentication refused: bad ownership or modes for file /home/aliceB/.ssh/authorized_keys
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In this case, failure of key authentication is due to the fact that the permission or ownership ~/.ssh/authorized_keys file is not correct. Typically this error can happen if ~/.ssh/authorized_keys is read accessible to anyone but yourself. To fix this problem, change the file permission as follows.
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$ chmod 700 ~/.ssh/authorized_keys
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--------------------------------------------------------------------------------
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via: http://xmodulo.com/how-to-enable-ssh-login-without.html
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作者：[Dan Nanni][a]
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译者：[译者ID](https://github.com/译者ID)
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||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
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|
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[a]:http://xmodulo.com/author/nanni
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How to set up networking between Docker containers
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================================================================================
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As you may be aware, Docker container technology has emerged as a viable lightweight alternative to full-blown virtualization. There are a growing number of use cases of Docker that the industry adopted in different contexts, for example, enabling rapid build environment, simplifying configuration of your infrastructure, isolating applications in multi-tenant environment, and so on. While you can certainly deploy an application sandbox in a standalone Docker container, many real-world use cases of Docker in production environments may involve deploying a complex multi-tier application in an ensemble of multiple containers, where each container plays a specific role (e.g., load balancer, LAMP stack, database, UI).
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There comes the problem of **Docker container networking**: How can we interconnect different Docker containers spawned potentially across different hosts when we do not know beforehand on which host each container will be created?
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One pretty neat open-source solution for this is [weave][1]. This tool makes interconnecting multiple Docker containers pretty much hassle-free. When I say this, I really mean it.
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In this tutorial, I am going to demonstrate **how to set up Docker networking across different hosts using weave**.
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### How Weave Works ###
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Let's first see how weave works. Weave creates a network of "peers", where each peer is a virtual router container called "weave router" residing on a distinct host. The weave routers on different hosts maintain TCP connections among themselves to exchange topology information. They also establish UDP connections among themselves to carry inter-container traffic. A weave router on each host is then connected via a bridge to all other Docker containers created on the host. When two containers on different hosts want to exchange traffic, a weave router on each host captures their traffic via a bridge, encapsulates the traffic with UDP, and forwards it to the other router over a UDP connection.
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Each weave router maintains up-to-date weave router topology information, as well as container's MAC address information (similar to switch's MAC learning), so that it can make forwarding decision on container traffic. Weave is able to route traffic between containers created on hosts which are not directly reachable, as long as two hosts are interconnected via an intermediate weave router on weave topology. Optionally, weave routers can be set to encrypt both TCP control data and UDP data traffic based on public key cryptography.
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### Prerequisite ###
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Before using weave on Linux, of course you need to set up Docker environment on each host where you want to run [Docker][2] containers. Check out [these][3] [tutorials][4] on how to create Docker containers on Ubuntu or CentOS/Fedora.
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Once Docker environment is set up, install weave on Linux as follows.
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$ wget https://github.com/zettio/weave/releases/download/latest_release/weave
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$ chmod a+x weave
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$ sudo cp weave /usr/local/bin
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Make sure that /usr/local/bin is include in your PATH variable by appending the following in /etc/profile.
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export PATH="$PATH:/usr/local/bin"
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Repeat weave installation on every host where Docker containers will be deployed.
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Weave uses TCP/UDP 6783 port. If you are using firewall, make sure that these port numbers are not blocked by the firewall.
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### Launch Weave Router on Each Host ###
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When you want to interconnect Docker containers across multiple hosts, the first step is to launch a weave router on every host.
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On the first host, run the following command, which will create and start a weave router container.
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$ sudo weave launch
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The first time you run this command, it will take a couple of minutes to download a weave image before launching a router container. On successful launch, it will print the ID of a launched weave router.
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To check the status of the router, use this command:
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$ sudo weave status
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Since this is the first weave router launched, there will be only one peer in the peer list.
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You can also verify the launch of a weave router by using docker command.
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$ docker ps
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On the second host, run the following command, where we specify the IP address of the first host as a peer to join.
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$ sudo weave launch <first-host-IP-address>
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When you check the status of the router, you will see two peers: the current host and the first host.
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As you launch more routers on subsequent hosts, the peer list will grow accordingly. When launching a router, just make sure that you specify any previously launched peer's IP address.
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At this point, you should have a weave network up and running, which consists of multiple weave routers across different hosts.
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### Interconnect Docker Containers across Multiple Hosts ###
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Now it is time to launch Docker containers on different hosts, and interconnect them on a virtual network.
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Let's say we want to create a private network 10.0.0.0/24, to interconnect two Docker containers. We will assign random IP addressses from this subnet to the containers.
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When you create a Docker container to deploy on a weave network, you need to use weave command, not docker command. Internally, the weave command uses docker command to create a container, and then sets up Docker networking on it.
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Here is how to create a Ubuntu container on hostA, and attach the container to 10.0.0.0/24 subnet with an IP addresss 10.0.0.1.
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hostA:~$ sudo weave run 10.0.0.1/24 -t -i ubuntu
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On successful run, it will print the ID of a created container. You can use this ID to attach to the running container and access its console as follows.
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hostA:~$ docker attach <container-id>
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Move to hostB, and let's create another container. Attach it to the same subnet (10.0.0.0/24) with a different IP address 10.0.0.2.
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hostB:~$ sudo weave run 10.0.0.2/24 -t -i ubuntu
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Let's attach to the second container's console as well:
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hostB:~$ docker attach <container-id>
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At this point, those two containers should be able to ping each other via the other's IP address. Verify that from each container's console.
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If you check the interfaces of each container, you will see an interface named "ethwe" which is assigned an IP address (e.g., 10.0.0.1 and 10.0.0.2) you specified.
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### Other Advanced Usages of Weave ###
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Weave offers a number of pretty neat features. Let me briefly cover a few here.
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#### Application Isolation ####
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Using weave, you can create multiple virtual networks and dedicate each network to a distinct application. For example, create 10.0.0.0/24 for one group of containers, and 10.10.0.0/24 for another group of containers, and so on. Weave automatically takes care of provisioning these networks, and isolating container traffic on each network. Going further, you can flexibly detach a container from one network, and attach it to another network without restarting containers. For example:
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First launch a container on 10.0.0.0/24:
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$ sudo weave run 10.0.0.2/24 -t -i ubuntu
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Detach the container from 10.0.0.0/24:
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$ sudo weave detach 10.0.0.2/24 <container-id>
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Re-attach the container to another network 10.10.0.0/24:
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$ sudo weave attach 10.10.0.2/24 <container-id>
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Now this container should be able to communicate with other containers on 10.10.0.0/24. This is a pretty useful feature when network information is not available at the time you create a container.
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#### Integrate Weave Networks with Host Network ####
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Sometimes you may need to allow containers on a virtual weave network to access physical host network. Conversely, hosts may want to access containers on a weave network. To support this requirement, weave allows weave networks to be integrated with host network.
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For example, on hostA where a container is running on network 10.0.0.0/24, run the following command.
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hostA:~$ sudo weave expose 10.0.0.100/24
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This will assign IP address 10.0.0.100 to hostA, so that hostA itself is also connected to 10.0.0.0/24 network. Obviously, you need to choose an IP address which is not used by any other containers on the network.
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At this point, hostA should be able to access any containers on 10.0.0.0/24, whether or not the containers are residing on hostA. Pretty neat!
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### Conclusion ###
|
||||
|
||||
As you can see, weave is a pretty useful Docker networking tool. This tutorial only covers a glimpse of [its powerful features][5]. If you are more ambitious, you can try its multi-hop routing, which can be pretty useful in multi-cloud environment, dynamic re-routing, which is a neat fault-tolerance feature, or even its distributed DNS service which allows you to name containers on weave networks. If you decide to use this gem in your environment, feel free to share your use case!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://xmodulo.com/networking-between-docker-containers.html
|
||||
|
||||
作者：[Dan Nanni][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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://xmodulo.com/author/nanni
|
||||
[1]:https://github.com/zettio/weave
|
||||
[2]:http://xmodulo.com/recommend/dockerbook
|
||||
[3]:http://xmodulo.com/manage-linux-containers-docker-ubuntu.html
|
||||
[4]:http://xmodulo.com/docker-containers-centos-fedora.html
|
||||
[5]:http://zettio.github.io/weave/features.html
|
||||
@ -0,0 +1,100 @@
|
||||
Linux FAQs with Answers--How to compress JPEG images from the command line on Linux
|
||||
================================================================================
|
||||
> **Question**: I have several JPEG photo images I have taken using a digital camera. I would like to optimize and compress the JPEG pictures before uploading them to Dropbox. What is the easiest way to compress JPEG images without losing their quality on Linux?
|
||||
|
||||
Image resolution of today's picture taking gadgets (e.g., smartphones, digital cameras) keeps increasing. Even 36.3 Megapixel Nikon D800 recently hit the consumer market, and this trend will continue. While modern gadgets continue to produce increasingly high resolution images, we may often want to post-process and compress their sizes before uploading them to a storage-limited and bandwidth-restricted cloud.
|
||||
|
||||
In fact, there is a way to compress JPEG images easily on Linux. A command-line tool called jpegoptim allows you do "lossless" optimization on JPEG images, so you can compress JPEG pictures without sacrificing their quality. In case your storage or bandwidth budget is really low, jpegoptim allows you to do "lossy" compression as well by adjusting image quality.
|
||||
|
||||
For those interested in compressing PNG images, refer to [this guideline][1] instead.
|
||||
|
||||
### Install Jpegoptim on Linux ###
|
||||
|
||||
To install jpegoptim on Ubuntu, Debian or Linux Mint:
|
||||
|
||||
$ sudo apt-get install jpegoptim
|
||||
|
||||
To install jpegoptim on Fedora:
|
||||
|
||||
$ sudo yum install jpegoptim
|
||||
|
||||
To install jpegoptim on CentOS/RHEL, first enable [EPEL repo][2], and then run:
|
||||
|
||||
$ sudo yum install jpegoptim
|
||||
|
||||
### Compress JPEG Images Losslessly ###
|
||||
|
||||
To compress a JPG picture losslessly, simply run:
|
||||
|
||||
$ jpegoptim photo.jpg
|
||||
|
||||
----------
|
||||
|
||||
photo.jpg 2048x1536 24bit N ICC JFIF [OK] 882178 --> 821064 bytes (6.93%), optimized.
|
||||
|
||||
Note that the original input image will be overwritten with a compressed impage.
|
||||
|
||||
If jpegoptim is not able to further optimize an image losselessly, it will skip overwriting it.
|
||||
|
||||
$ jpegoptim -v photo.jpg
|
||||
|
||||
----------
|
||||
|
||||
photo.jpg 2048x1536 24bit N ICC JFIF [OK] 821064 --> 821064 bytes (0.00%), skipped.
|
||||
|
||||
If you want to preserve an original image, use "-d" option to specify a target directory.
|
||||
|
||||
$ jpegoptim -d ./compressed photo.jpg
|
||||
|
||||
An compressed image will then be placed (with the same name as the input file) in ./compressed directory.
|
||||
|
||||
If you want to preserve file creation/modification time, use "-p" option as follows. Then a compressed image will be placed with the same date and time as the original image.
|
||||
|
||||
$ jpegoptim -d ./compressed -p photo.jpg
|
||||
|
||||
If you simply check out possible lossless compression ratio without actually compressing it, use "-n" option to "simulate" compression. Then it will simply print results without actually performing compression.
|
||||
|
||||
$ jpegoptim -n photo.jpg
|
||||
|
||||
### Compress JPEG Images Lossily ###
|
||||
|
||||
In case you really want to save storage space, you can do lossy compression on large JPEG pictures.
|
||||
|
||||
In this case, use "-m<maximum-quality>" option, where maximum quality is specified in the range of 0 and 100 (0 is the highest quality, and 100 is the lowest quality).
|
||||
|
||||
For example, to compress an image with 50% quality:
|
||||
|
||||
$ jpegoptim -m50 photo.jpg
|
||||
|
||||
----------
|
||||
|
||||
photo.jpg 2048x1536 24bit N ICC JFIF [OK] 882178 --> 301780 bytes (65.79%), optimized.
|
||||
|
||||
You will get a smaller image at the cost of reduced quality.
|
||||
|
||||
|
||||
|
||||
### Compress Multiple JPEG Images in a Batch ###
|
||||
|
||||
Often times you need to compress many JPEG image files in a directory. In that case, you can use the following shell script.
|
||||
|
||||
#!/bin/sh
|
||||
|
||||
# compress all *.jpg files in the current directory
|
||||
# and place them in ./compressed directory
|
||||
# with the same modification date as original files.
|
||||
for i in *.jpg; do jpegoptim -d ./compressed -p "$i"; done
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://ask.xmodulo.com/compress-jpeg-images-command-line-linux.html
|
||||
|
||||
作者：[Dan Nanni][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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://ask.xmodulo.com/author/nanni
|
||||
[1]:http://xmodulo.com/how-to-compress-png-files-on-linux.html
|
||||
[2]:http://xmodulo.com/how-to-set-up-epel-repository-on-centos.html
|
||||
@ -0,0 +1,121 @@
|
||||
Linux FAQs with Answers--How to install and access CentOS remote desktop on VPS
|
||||
================================================================================
|
||||
> **Question**: I want to install CentOS desktop on VPS, and be able to access the desktop GUI remotely from home. What is a recommended way to set up and access CentOS-based remote desktop on VPS?
|
||||
|
||||
Nowadays teleworking or remote working with flexible hours is increasingly popular in tech industry. One of the enabling technologies behind this trend is remote desktop. Your desktop environment is in the cloud, and you can access the remote desktop anywhere you go, either from home or at your workplace.
|
||||
|
||||
This tutorial describes how you can set up CentOS based remote desktop on VPS. Here we are going to demonstrate CentOS 7 based environment.
|
||||
|
||||
We assume that you already created a CentOS 7 VPS instance somewhere (e.g., using [DigitalOcean][1] or Amazon EC2). Make sure that the VPS instance has at least 1GB memory. Otherwise, CentOS desktop will crash when you try to access remote desktop.
|
||||
|
||||
### Step One: Install CentOS Desktop ###
|
||||
|
||||
If an available CentOS image is a minimal version of CentOS without desktop, you will need to install desktop (e.g., GNOME) on your CentOS VPS before proceeding. For example, DigitalOcean's CentOS image is such a minimal version, which requires [desktop GUI installation][2] as follows.
|
||||
|
||||
# yum groupinstall "GNOME Desktop"
|
||||
|
||||
Reboot a VPS after finishing installation.
|
||||
|
||||
### Step Two: Install and Configure VNC Server ###
|
||||
|
||||
The next step is to install and configure VNC server. We are going to use TigerVNC, an open-source VNC server implementation.
|
||||
|
||||
# yum install tigervnc-server
|
||||
|
||||
Now create a user account (e.g., xmodulo) which will be used to access remote desktop.
|
||||
|
||||
# useradd xmodulo
|
||||
# passwd xmodulo
|
||||
|
||||
When a user tries to access remote desktop using VNC, a dedicated VNC server daemon will be launched to handle its requests. This means that you will need to create a separate VNC server configuration for each user.
|
||||
|
||||
CentOS 7 relies on systemd to manage and configure system services. So we are going to configure VNC server for xmodulo user using systemd.
|
||||
|
||||
Let's first check the status of VNC server by running either command below:
|
||||
|
||||
# systemctl status vncserver@:.service
|
||||
# systemctl is-enabled vncserver@.service
|
||||
|
||||
By default, freshly installed VNC service is not active (disabled).
|
||||
|
||||
|
||||
|
||||
Now create a VNC service configuration for xmodulo user by copying a generic VNC service unit file as follows.
|
||||
|
||||
# cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:1.service
|
||||
|
||||
Open the configuration file with a text editor, and replace <USER> with an actual user name (e.g., xmodulo) under [Service] section. Also, append "-geometry <resolution>" parameter in ExecStart. In the end, the following two lines with bold font will be modified.
|
||||
|
||||
# vi /etc/systemd/system/vncserver@:1.service
|
||||
|
||||
----------
|
||||
|
||||
[Service]
|
||||
Type=forking
|
||||
# Clean any existing files in /tmp/.X11-unix environment
|
||||
ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
|
||||
ExecStart=/sbin/runuser -l xmodulo -c "/usr/bin/vncserver %i -geometry 1024x768"
|
||||
PIDFile=/home/xmodulo/.vnc/%H%i.pid
|
||||
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
|
||||
|
||||
Now set up (optional) VNC password for xmodulo user for security. For this, switch to the user, and run vncserver command.
|
||||
|
||||
# su - xmodulo
|
||||
# vncserver
|
||||
|
||||
You will be prompted to enter a VNC password for the user. Once the password is set, you will need to use this password to gain access to remote desktop.
|
||||
|
||||
|
||||
|
||||
Finally, reload services to activate the new VNC configuration:
|
||||
|
||||
# systemctl daemon-reload
|
||||
|
||||
and enable VNC service to make it start automatically upon boot:
|
||||
|
||||
# systemctl enable vncserver@:1.service
|
||||
|
||||
Check the port number that a VNC server is listening on by running:
|
||||
|
||||
# netstat -tulpn | grep vnc
|
||||
|
||||
|
||||
|
||||
Port 5901 is the default port number for VNC client to connect to a VNC server.
|
||||
|
||||
### Step Three: Connect to Remote Desktop over SSH ###
|
||||
|
||||
By design, Remote Frame Buffer (RFB) protocol used by VNC is not a secure protocol. Thus it is not a good idea to directly connect to a remote VNC server running on VPS using a VNC client. Any sensitive information such as password could easily be leaked from VNC traffic. So instead, I strongly recommend that you [tunnel VNC traffic][3] over a secure SSH tunnel, as described here.
|
||||
|
||||
On a local host where you want to run VNC client, create an SSH tunnel to a remote VPS using the following command. When prompted for SSH password, type the password of the user.
|
||||
|
||||
$ ssh xmodulo@<VPS-IP-address> -L 5901:127.0.0.1:5901
|
||||
|
||||
Replace "xmodulo" with your own VNC user, and fill in the IP address of your VPS instance.
|
||||
|
||||
Once an SSH tunnel is established, remote VNC traffic will be routed over the SSH tunnel, and be sent to 127.0.0.1:5901.
|
||||
|
||||
Now go ahead and launch your favorite VNC client (e.g., vinagre), and connect to 127.0.0.1:5901.
|
||||
|
||||
|
||||
|
||||
You will be asked to enter a VNC password. When you type a correct VNC password, you will finally be able to CentOS remote desktop on VPS securely.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://ask.xmodulo.com/centos-remote-desktop-vps.html
|
||||
|
||||
作者：[Dan Nanni][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) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://ask.xmodulo.com/author/nanni
|
||||
[1]:http://xmodulo.com/go/digitalocean
|
||||
[2]:http://xmodulo.com/how-to-install-gnome-desktop-on-centos.html
|
||||
[3]:http://xmodulo.com/how-to-set-up-vnc-over-ssh.html
|
||||
Loading…
Reference in New Issue
Block a user