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Docker 0.7 Runs On All Linux Distributions

Soulskill posted 1 year,25 days | from the go-big-or-go-home dept.

Software 88

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.'"

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What? (4, Funny)

For a Free Internet (1594621) | 1 year,25 days | (#45533207)

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.

Re:What? (-1, Offtopic)

larry bagina (561269) | 1 year,25 days | (#45533639)

Well, I'm sure you know what docking [urbandictionary.com] is. So a docker is someone who, well, docks [google.com] .

That explains why slashdot is posting it.

Awesome! (5, Insightful)

mythosaz (572040) | 1 year,25 days | (#45533261)

...now what the fuck is a docker?

Re:Awesome! (5, Funny)

Anonymous Coward | 1 year,25 days | (#45533303)

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.

Re:Awesome! (1)

Jeremiah Cornelius (137) | 1 year,25 days | (#45533355)

British thing?

"Docker is Pants"!

Yanks won't get...

Re:Awesome! (0)

Anonymous Coward | 1 year,25 days | (#45535927)

But http://us.dockers.com/home/index.jsp is an American company...

Re:Awesome! (1)

Jeremiah Cornelius (137) | 1 year,24 days | (#45539159)

Yeah. But they're imported, like sponge moulds and venereal disease.

Now, when I can walk into a Marks & Spencer or Debenham's in New York? Yank pants (underwear) is different, and after more than 20 years, I can't ever get quite used to it.

Re:Awesome! (-1, Troll)

Jmc23 (2353706) | 1 year,25 days | (#45533359)

Well, at the very least we've learnt that a Mythosaz is a being too stupid to click on a link yet still able to read slashdot.

Now if we compare that against the typical slashdot user, we're back at square one.

Re:Awesome! (4, Insightful)

spike hay (534165) | 1 year,25 days | (#45533409)

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

Re:Awesome! (-1, Troll)

kjs3 (601225) | 1 year,25 days | (#45533685)

Yes...I hate it when people don't explain what that whole "linux" and "java" thing is when they post. If I don't know what it is, noone does.

Re:Awesome! (0, Insightful)

Anonymous Coward | 1 year,25 days | (#45533735)

You're a real fucking dipshit aren't you.

Re:Awesome! (0)

kjs3 (601225) | 1 year,25 days | (#45533859)

ACs are so cute.

Re:Awesome! (0, Insightful)

Anonymous Coward | 1 year,25 days | (#45534005)

You're assuming he didn't mod you as -1, dumbarse.

Re:Awesome! (3, Informative)

spike hay (534165) | 1 year,25 days | (#45534147)

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

Re:Awesome! (1)

pscottdv (676889) | 1 year,25 days | (#45533367)

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

Re:Awesome! (3, Insightful)

kjs3 (601225) | 1 year,25 days | (#45533725)

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

Re:Awesome! (5, Informative)

bondsbw (888959) | 1 year,25 days | (#45533415)

From Wikipedia [wikipedia.org] :

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

And then [wikipedia.org] :

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.

Re:Awesome! (2, Funny)

Anonymous Coward | 1 year,25 days | (#45534201)

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

Re:Awesome! (2)

waffle zero (322430) | 1 year,25 days | (#45535321)

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

Re:Awesome! (1)

Lennie (16154) | 1 year,24 days | (#45539403)

It is actually used for application containers.

Which means, only the application is started, not a complete userspace.

Making it even more efficient.

Re:Awesome! (0)

Anonymous Coward | 1 year,19 days | (#45581381)

For a second you had me going.
  I thought VZ and LXC had some new competition, but this is just TOTALLY DIFFERENT!

Re:Awesome! (2, Informative)

Anonymous Coward | 1 year,25 days | (#45533433)

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!

Re:Awesome! (3, Informative)

majesticmerc (1353125) | 1 year,25 days | (#45533589)

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.

Re:Awesome! (2, Interesting)

Anonymous Coward | 1 year,25 days | (#45533647)

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).

Re:Awesome! (4, Informative)

kjs3 (601225) | 1 year,25 days | (#45533837)

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.

Re:Awesome! (2)

gmuslera (3436) | 1 year,25 days | (#45534527)

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.

Re:Awesome! (2)

visualight (468005) | 1 year,25 days | (#45533651)

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.

Re:Awesome! (1)

kjs3 (601225) | 1 year,25 days | (#45533909)

I'm not sure what the point is here. I mean, I suppose your right in the same sense as Drupal is a front end for a database and PHP is a front end for a web server. I just don't get the derisive tone.

Re:Awesome! (1)

visualight (468005) | 1 year,25 days | (#45534589)


First, I think Docker is pretty awesome. Many people have been struggling with home grown solutions for LXC for a while now and Docker comes along and wows us, like dang it's clear how it should be done now that I've seen it.

But. I am disappointed in the lack of words given to LXC.

Your analogy would be appropriate if dozens of people worked for almost a decade inventing a database and then someone had a great idea for a really usable front end. And presented it to a database ignorant world with hardly a nod to the guys who made the database. I'm not feeling any derision towards the Docker guys, but disappointment, yes.

Re:Awesome! (1)

kjs3 (601225) | 1 year,25 days | (#45536359)

If you go to the Drupal page, you get a lot about how great Drupal is, and one line about "and we use one of these databases". So I think my analogy is spot on. Further, if you do more than read the linked Docker announcement, the fact they are layered on LXC is pretty much all over the docs. Or do you suggest we have to start referring to it as "LXC/Docker" to make sure noone could possibly not know there's a connection.

Re:Awesome! (0)

Anonymous Coward | 1 year,25 days | (#45536591)

Conventionally it would be "Docker/LXC", since Docker is built upon LXC not the other way around. But, yes, I'm being pedantic. You make your point well.

Re:Awesome! (1)

Lennie (16154) | 1 year,24 days | (#45539443)

The Docker folks actually want to support multiple operating system virtualization technologies.

So Docker doesn't just want to support LXC, if someone wants to write it, they want to support the same on open source Solaris and FreeBSD too for example.

Re:Awesome! (1)

visualight (468005) | 1 year,22 days | (#45556609)

...And presented it to a database ignorant world...

It's hardly the same.

Re:Awesome! (5, Funny)

mythosaz (572040) | 1 year,25 days | (#45535111)


...what the fuck is LXC?

Re:Awesome! (2)

pmontra (738736) | 1 year,25 days | (#45535885)

I googled LXC for you and found http://en.wikipedia.org/wiki/Linux_Containers [wikipedia.org]

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.

Re:Awesome! (1)

sunderland56 (621843) | 1 year,25 days | (#45534061)

Docker is an open-source project to easily create lightweight, portable, self-sufficient containers

The Christmas gift-giving season is coming. Everyone is going to need some lightweight, portable containers, right?

Re:Awesome! (1)

mikael (484) | 1 year,24 days | (#45542459)

I had to look at their website to figure it out. The two most important criteria for me when considering installing any new Linux service is: (1) Is it a server, (2) Does it provide access to a filesystem and (3) Does it access the window system?

Docker is a type of virtualization system. But rather than duplicating the entire set of kernel services; file systems, displays, IO ports, hardware, it only duplicates the network services through "containers". These are file systems that hook up to the OS and file system through the network layer such that containers can be attached to each other and communicate across networks. It's a sort of distributed network mirroring file system. Wonderful for sys-admins because they can maintain duplicate copies of a standard filesystem across multiple desktop and server systems. But it also makes for perfect rootkitware because it could be pre-installed onto standard Linux distro's with the mirrored copies on some cloud server.

Re:Awesome! (1)

CAPSLOCK2000 (27149) | 1 year,25 days | (#45533593)

The first word of the summary is a link explaining exactly what Docker is. Click it!

Re:Awesome! (0)

Anonymous Coward | 1 year,25 days | (#45534433)

And then continue to wonder what the hell most of that means.

Re:Awesome! (1)

rubycodez (864176) | 1 year,25 days | (#45534717)

you fail at having any understanding of proper technical journalism, just as the summary writer did. Slashdot is becoming electronic tabloid trash.

Re:Awesome! (0)

Anonymous Coward | 1 year,25 days | (#45533743)

Re:Awesome! (0)

Anonymous Coward | 1 year,24 days | (#45546111)

...now what the fuck is a docker?

At some point, Slashdot was a source of news for knowledgeable people in the IT/tech industry.

It's obviously not the case anymore :-)

relevant Onion article (4, Insightful)

spike hay (534165) | 1 year,25 days | (#45533275)

here [theonion.com]

relevant Seuss (2)

Em Adespoton (792954) | 1 year,25 days | (#45533885)

here [ufl.edu]

Docker is pretty cool (1)

Jeremiah Cornelius (137) | 1 year,25 days | (#45533277)

Similar to OSX bundles, or to Application Virtualization (ThinApp) on Windows.

Combined with a universal overlay filesystem, this is a great thing.

Re:Docker is pretty cool (4, Funny)

bananaquackmoo (1204116) | 1 year,25 days | (#45533307)

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

Re:Docker is pretty cool (1)

Jeremiah Cornelius (137) | 1 year,25 days | (#45533403)

It's a convenient floor topping, that's also a dessert wax! Next time insist on Docker-brand hungry nuns and orphans.

Re:Docker is pretty cool (0)

Anonymous Coward | 1 year,25 days | (#45533643)

It's like Aminator, only it produces Linux Containers (LXCs) instead of AMIs. Linux Containers are like VM images, only lighter weight and require significant cooperation from the kernel. VM images are like bootable file systems, only implemented as a file/files in an existing file system.

Re:Docker is pretty cool (2)

spike hay (534165) | 1 year,25 days | (#45533353)

So it doesn't have to do with pants?

Re:Docker is pretty cool (-1)

Anonymous Coward | 1 year,25 days | (#45533391)

That's right. Keep copying other OSs, open sores faggots! That's all you got. Keep ripping everyone else off. No original thoughts.
Or to quote you faggots when you talk about everyone else; "Where's teh innovationzzzz!?!?!111?!?//!?!"

Re:Docker is pretty cool (1)

FunkyRider (1128099) | 1 year,25 days | (#45533501)

But have you paid your windows and office license fee?

Yeah but... (1)

scarboni888 (1122993) | 1 year,25 days | (#45533401)

Does it run on Windows?

Why that name? (1)

wonkey_monkey (2592601) | 1 year,25 days | (#45533447)

If you had to guess what a piece of software called "Docker" did, what would you think?

Re:Why that name? (1)

Anonymous Coward | 1 year,25 days | (#45533573)

hmmm. gotta be either a semi-violent porn simulation or a visual desktop theme that gives that dressed-up-but-not-that--dressed-up casual look. cant tell, but site's slashdotted so must be the first one.

Re: Why that name? (1)

tysonedwards (969693) | 1 year,25 days | (#45533601)

Here I was thinking that it was part of Unity, namely the side taskbar. Then I was thinking... Why would a taskbar need it's own storage API? Then I remembered... It isn't the first time that Canonical added some odd cruft to Unity.

Then I searched it out and scratched my head as to why those things would need to be added to chroot.

Re:Why that name? (0)

Anonymous Coward | 1 year,25 days | (#45533631)

If you had to guess what a piece of software called "Docker" did, what would you think?

It docks ?
Am I right ?

Re:Why that name? (1)

kjs3 (601225) | 1 year,25 days | (#45533713)

If you had to guess what a piece of software called "Apache" did, what would you think? If you had to guess what a piece of software called "Hadoop" did, what would you think? If you had to guess what a piece of software called "C" did, what would you think? If you had to guess what a piece of software called "Postgres" did, what would you think? If you had to guess....blah, blah, blah...

Re:Why that name? (-1)

Anonymous Coward | 1 year,25 days | (#45534029)

I used to think that stupid people lived their own punishment, but I see from your behaviour that you consider yourself to be quite an intellectual. You're not. Now go back to your advertising catalogues of women modelling underwear. The grown ups are talking.


Anonymous Coward | 1 year,25 days | (#45534055)

do it.

Re:Why that name? (3, Informative)

LMariachi (86077) | 1 year,25 days | (#45534323)

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.

Re:Why that name? (1)

kjs3 (601225) | 1 year,24 days | (#45538355)

Must not name collide with anything related to computers, no matter how tenuously related. Gotcha. Redefine the issue enough times, you get to be right, I suppose.

Re:Why that name? (1)

Anonymous Coward | 1 year,25 days | (#45536427)

I'd think it were a system tray [debian.org] .

chroot (1)

digitalPhant0m (1424687) | 1 year,25 days | (#45533539)

Looks like someone figured out how to put a fancy spin on chroot. Sweet.

Re:chroot (2)

visualight (468005) | 1 year,25 days | (#45533625)

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.

Re:chroot (1)

fatphil (181876) | 1 year,25 days | (#45536219)

Despite the fact that the cgroups maintainer have openly admitted that cgoups is now (as of mid-september, at least) a completely illogical mess?

We need fewer clients for cgoups, not more, so that it can be killed with fire.

And docker is? (1)

nurb432 (527695) | 1 year,25 days | (#45533549)

I shouldn't have to go look it up.

Years coming. (1, Interesting)

visualight (468005) | 1 year,25 days | (#45533605)

Linux Containers are one of the greatest things to come to linux in the last ten years. Looking at the comments posted here already it's no wonder my pleas for time to work in something like this never got any traction. Docker's going to be a game changer.

All you managers that didn't think LXC was relevant, look at Docker and suck it. Could have been you dumbass.

Re:Years coming. (0)

Anonymous Coward | 1 year,25 days | (#45534459)

It would have helped considerably if someone had thought to include a sentence or two explaining what docker was, and why it is important / what it actually means. The best I can come up with after reading all the comments and checking out the site, is that it is something like a chroot management thingy, but not quite the same as an actual kvm or xen instance.

Re:Years coming. (1)

jopsen (885607) | 1 year,25 days | (#45534651)

From what I understand it's a lightweight virtual machine... I'm considering it for a case where we need to run a lot unit tests... the tests leave the machine in a dirty state, so running the tests inside an lxc container would fix that... A copy-on-write file system would make reseting the machine cheap, at lot cheaper than restarting a virtual machine from snapshot..

Re:Years coming. (1)

Lennie (16154) | 1 year,24 days | (#45539487)

That is exactly the kind of things it is for.

Re:Years coming. (0)

Anonymous Coward | 1 year,25 days | (#45534505)

Finally, a thoughtful and accurate explanation of Docker's purpose.

Re:Years coming. (0, Insightful)

Anonymous Coward | 1 year,25 days | (#45534795)

Looking at the comments posted here already

Most of the cool kids left here long ago. This story? Lucky if it gets 100 posts, and if it does 75 will be "wtf is it?" Today we have angry libtards standing by to spend all their mod points on the next global warming story.

All? I think not! (0)

Anonymous Coward | 1 year,25 days | (#45533661)

Sure doesn't seem to want to run on my Yggdrasil box.

That's fantastic! (1)

Chris Mattern (191822) | 1 year,25 days | (#45534521)

What the hell does it do?

Technically, (0)

Anonymous Coward | 1 year,25 days | (#45534979)

How is it better than ZFS snapshots?

0.# (0)

Anonymous Coward | 1 year,25 days | (#45535173)

A zero-point-something release is newsworthy? Hear ye, hear ye, alpha quality shite runs on all Linux distributions!

Re:0.# (0)

Anonymous Coward | 1 year,25 days | (#45535229)

But but but but it's on GIT HUB!!!! so it's TRENDY!!!!!!!!!!!!!!

After WTF is Docker... (1)

nurb432 (527695) | 1 year,25 days | (#45535553)

Aside from the fact we should not have to look up some esoteric item to see what the hell we are talking about, and if we care...

For those in the know: is this something like thinapp or cameyo for Linux that is truly virtual, or is it more of a portable jail? Not that i cant read, but i see the words 'virtual' misused so often it shard to tell without digging too deep. If it is truly virtualized that is cool, if its yet anther jail/chroot management tool, *yawn*

Re:After WTF is Docker... (1)

Lennie (16154) | 1 year,24 days | (#45539517)

Yes, containers are like jail/chroot. But containers in more recent Linux kernels are now mature enough to almost do all things Solaris Zones does. Like proper security and with use of the http://criu.org/ [criu.org] project, you can also do live-migration in many cases.

What is a Linux container and why do I care? (1)

Anonymous Coward | 1 year,25 days | (#45536819)

The main question is - what is a Linux container, and why do I care about it? I don't care about some awfully named Linux program that has been ported to other distros. Why call it "Docker" if it has nothing to do with men's slacks or the icon dock at the bottom of the screen? Asking what Docker is results in a blizzard of acronyms and terms that only matter to someone who already knows what it is. The real question is, what is a Linux container? Why do people use them? Anyone talking about Linux containers needs to have the 30-second "elevator pitch" to explain why they're great and why they're going to rule the world. Otherwise, what's the point?

Just something simple like this: "Docker is a utility for Linux containers, an exciting technology for embedding Linux in cargo containers to create smart cargo containers capable of telling the cargomaster their temperature, weight, time at sea, and destination, to allow more efficient ship loading and cargo routing, which will save shipping firms millions of dollars each month."

OpenShift (0)

Anonymous Coward | 1 year,25 days | (#45536935)

How does this differ from what OpenShift is doing?

Re:OpenShift (1)

Lennie (16154) | 1 year,24 days | (#45539591)

OpenShift runs tenant programs in a SELinux 'jail', but OpenShift is going to adopt Docker. Just like OpenStack has already adopted Docker support. There is even an OpenStack project by many companies, including RedHat, which is gonna work on creating a well integrated OpenShift and OpenStack combination. The project name is: Solum.

but more importantly, does it run cargo pants? (1)

youn (1516637) | 1 year,24 days | (#45537175)

it is an important feature of dockers :p

GNOME Classic Mode (0)

Anonymous Coward | 1 year,24 days | (#45537569)

How is MATE better than GNOME 3.8 in Classic mode?

Packaging? (2)

temcat (873475) | 1 year,24 days | (#45537861)

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.)

Re:Packaging? (1)

Lennie (16154) | 1 year,24 days | (#45539559)

In a way, yes.

You specify what distro and version your application can run on and you create a container with Docker which uses that image as a base to run your application.

Basically: Linux-application on top of Linux-distribution inside a container on top of an other Linux distribution.

WTF is a slashtard? (0)

Anonymous Coward | 1 year,24 days | (#45547231)

Seriously, this is what Slashdot has come to? Despite multiple attempts to indicate what Docker is and why it represents an impressive technological feat, a chorus of "WTF is Docker??? hurr hurr" resounds? Take a moment & check it out, for Pete's sake. I think I'm done with Slashdot if this is what the discussion has descended to.

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