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Docker 0.7 Runs On All Linux Distributions

Posted by Soulskill on from the go-big-or-go-home dept.

rjmarvin writes "Docker 0.7 was released today, with 7 major new features including support to run on all Linux distributions. No longer capable solely on running on Debian and Ubuntu Linux, Docker 0.7 adds support for distributions such as Red Hat, SUSE, Gentoo and Arch. From the announcement: 'A key feature of Docker is the ability to create many copies of the same base filesystem almost instantly. Under the hood Docker makes heavy use of AUFS by Junjiro R. Okajima as a copy-on-write storage mechanism. AUFS is an amazing piece of software and at this point it’s safe to say that it has safely copied billions of containers over the last few years, a great many of them in critical production environments. Unfortunately, AUFS is not part of the standard linux kernel and it’s unclear when it will be merged. This has prevented docker from being available on all Linux systems. Docker 0.7 solves this problem by introducing a storage driver API, and shipping with several drivers. Currently 3 drivers are available: AUFS, VFS (which uses simple directories and copy) and DEVICEMAPPER, developed in collaboration with Alex Larsson and the talented team at Red Hat, which uses an advanced variation of LVM snapshots to implement copy-on-write. An experimental BTRFS driver is also being developed, with even more coming soon: ZFS, Gluster, Ceph, etc. When the docker daemon is started it will automatically select a suitable driver depending on its capabilities.'"

24 of 88 comments (clear)

  1. What? by For+a+Free+Internet · · Score: 2, Funny

    DOes this have something to do with boats? I hate boats, why is Slashdort posting news about boats? I mean, I really hate boats. Don't get me started, Slashdort.

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  2. Awesome! by mythosaz · · Score: 5, Insightful

    ...now what the fuck is a docker?

    1. Re:Awesome! by Anonymous Coward · · Score: 5, Funny

      I think I read something about this on the net. There was a "Day of the Docker" thing on BBC.. so I guess it must be some British thing 50 years in the making.

    2. Re:Awesome! by spike+hay · · Score: 4, Insightful

      It's customary to put a brief explanation of what the fuck the article is about in the summary.

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    3. Re:Awesome! by bondsbw · · Score: 5, Informative

      From Wikipedia:

      Docker is an open source project that automates the deployment of applications inside software containers.

      And then:

      Operating system-level virtualization is a server virtualization method where the kernel of an operating system allows for multiple isolated user-space instances, instead of just one. Such instances (often called containers, VEs, VPSs or jails) may look and feel like a real server, from the point of view of its owner.

      On Unix-based systems, this technology can be thought of as an advanced implementation of the standard chroot mechanism. In addition to isolation mechanisms, the kernel often provides resource management features to limit the impact of one container's activities on the other containers.

      So my takeaway is that each container would feel like a full virtual machine, but with only the overhead of separate user-spaces and without the overhead of loading an entire operating system into each. A neat approach, really.

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    4. Re:Awesome! by Anonymous Coward · · Score: 2, Informative

      It's a jigsaw. It's a power drill. It's a wood-turning lathe. It's an asphalt spreader. It's 67 tools in one!

    5. Re:Awesome! by majesticmerc · · Score: 3, Informative
      I read the "About Docker" page on their website and it says this:

      Docker is an open-source project to easily create lightweight, portable, self-sufficient containers from any application. The same container that a developer builds and tests on a laptop can run at scale, in production, on VMs, bare metal, OpenStack clusters, public clouds and more.

      Even after reading it, I've got no fucking idea what it does! Their "read more" page just shits out a whole load of buzzwords.

    6. Re:Awesome! by Anonymous Coward · · Score: 2, Interesting

      Even after reading it, I've got no fucking idea what it does! Their "read more" page just shits out a whole load of buzzwords.

      It's container-style virtualization. Which has been around forever. Even on Linux.

      But apparently, everything old is new again sometime, and this is the time.

      Granted, it's probably about time, after all, since Docker doesn't appear to suck complete ass and isn't commercial (either of which has largely been the main problem with previous Linux containerization).

    7. Re:Awesome! by visualight · · Score: 2

      I think the intent is for Docker to have the 'mind share' , so the about page is all about what Docker can do.

      All the work is done by LXC. Docker is a front end for LXC.

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    8. Re:Awesome! by kjs3 · · Score: 3, Insightful

      As far as I can tell it's a chroot jail with different limitations. FTFY

    9. Re:Awesome! by kjs3 · · Score: 4, Informative
      Docker is indeed hot right now, for some pretty good reasons.
      • - (Relatively) easy to use management wrapper around LCX, in particular quick deployment and a templating mechanism to describe container contents and deal with dependencies
      • - Uses a union filesystem to thiny provision containers, with development work to use other filesystem mechanisms to achieve the same goal
      • - There's a ecosystem to share containers similar to ecosystems around sharing pre-built virtual machines
      • - Backed by a commercial company

      Sure...done before. Evolution, not revolution. Very useful if you fit it's use case.

    10. Re:Awesome! by spike+hay · · Score: 3, Informative

      Everyone knows what Linux and Java are on Slashdot. Clearly, most people don't know what Docker is.

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    11. Re:Awesome! by Anonymous Coward · · Score: 2, Funny

      No doubt it'll be subsumed into systemd as one of its services next year.

    12. Re:Awesome! by gmuslera · · Score: 2

      Is more than just containers. You have containers, but oriented to run a single process (i.e. OpenVZ, another virtualization for Linux, usually runs a whole set of processes), uses cgroups to limit cpu/network/io, have its own users so the containers root is not the system one, and a very nice command to make things far easier than it was with LXC. Really have very little overhead (if any) compared with running native programs, but isolated from the filesystem/process/network

      But for me one of the strongest point on what they did with the union filesystem is letting the containers "inherit" filesystems without much overhead. you start with a base system, on it you install apache and get another container, on it install i.e. php (or you can do the same progression with i.e. java and jboss), and get another, and so on with your applications in other containersm, and you could create more children at all levels (i.e. a different set of apache modules, or a php compiled with different options, or a particular set of python libraries). And this approach adds eficiency as in the disk the children only have the differences with their parent, and as the base programs/libraries will be in one place on the disk will be cached just once, making things faster and using far less space. Not sure how that will play out with the device mapper, but with aufs it was nice.

    13. Re:Awesome! by mythosaz · · Score: 5, Funny

      Awesome!

      ...what the fuck is LXC?

    14. Re:Awesome! by waffle+zero · · Score: 2

      systemd already has systemd-nspawn, but it's not touted as a secure container.

    15. Re:Awesome! by pmontra · · Score: 2
      I googled LXC for you and found http://en.wikipedia.org/wiki/Linux_Containers

      LXC provides operating system-level virtualization not via a virtual machine, but rather provides a virtual environment that has its own process and network space. LXC relies on the Linux kernel cgroups functionality that was released in version 2.6.24. It also relies on other kinds of namespace-isolation functionality, which were developed and integrated into the mainline Linux kernel. It is used by Heroku to provide separation between their dynos.

  3. relevant Onion article by spike+hay · · Score: 4, Insightful

    here

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  4. Re:Docker is pretty cool by bananaquackmoo · · Score: 4, Funny

    That's nice. I still have no idea what it is.

  5. Re:Docker is pretty cool by spike+hay · · Score: 2

    So it doesn't have to do with pants?

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  6. Re:chroot by visualight · · Score: 2

    A lot of people have been working on this for a *long* time. I think the initial contributions to the kernel were from IBM maybe six years ago. This is much bigger than a fancy spin.

    *This* is what cgroups were put in place to do iirc.

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  7. relevant Seuss by Em+Adespoton · · Score: 2

    here

  8. Re:Why that name? by LMariachi · · Score: 3, Informative

    Except that a "dock" is already a common thing in computer UIs, whereas an Indian tribe and the name of a developer's kid's toy elephant are not. It's as if someone came out with a product called "mouseWM" that was neither a window manager nor accepted mouse input, but was actually a scripting language or something.

  9. Packaging? by temcat · · Score: 2

    Can Docker be used for distro-neutral application packaging on Linux? (May be a silly question, but I'm still not sure, even after reading TFA and comments.)