Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Docker 0.7 runs on all Linux distributions

blog.docker.io

Post reply on HN
Print view View original

51–60 of 131 posts

Re: Docker 0.7 runs on all Linux distributions

#51

Post by m_mueller »

alexlarsson wrote: post #38
m_mueller wrote: post #25

Earlier quoted context omitted.

One thing I've been wondering is whether the 42 limit was related to performance considerations. If yes, I actually somewhat like it - I'm a proponent to making systems behave in a way that they won't come around and bite you. Will a container based on, say, 200 layers still load and run with reasonable performance?

That depends on the backend a bit i guess. devicemapper "flattens" each layer, so the depth should have zero effect on the performance. For aufs, I have no real data, but I assume that a 42 layer image is somewhat slower than a 1 layer image. The fix for going to > 42 layers is to recreate a full image snapshot (using hard links to share file data) every N layers, so the performance would be somewhere between the per…

Doesn't 'flatten' mean that there's going to be a tradeoff between IO performance and storage size? If that's the case I'd like to have some control over what happens, at least with one of the implementations. Say, during development of a Dockerfile just use the layers as before, potentially without any depth limits, but when an image is ready being able to call 'flatten' manually.

Some background: Using 0.65 it took me several days to develop a Docker image with manually compiled versions of V8, PyV8, CouchDB, Flask, Bootstrap and some JS Libraries[1]. With no 42 limit it wouldn't have taken so long since I would have had way more caching points - however I'd also be afraid about performance.

[1] the image is available on the repository as ategra/xforge-dependencies. I can upload the Dockerfile to github if anyone is interested.

Re: Docker 0.7 runs on all Linux distributions

#52

Post by shykes »

shykes wrote: post #44
jfchevrette wrote: post #22

Unfortunately it looks like the documentation has not been updated yet... So much for feature #7. Documentation should be part of the development/release process

Documentation is definitely part of the process :) Apparently the documentation service triggered an incorrect build overnight. Until we fix that you can browse the latest version of the docs from the master branch: http://docs.docker.io/en/master

Quick update: until we figure out what broke the build on our ReadTheDocs.org setup, we switched the default branch to master. So if you visit http://docs.docker.io you will get the bleeding edge build of the documentation, which happens to be accurate since we released it this morning :)

Sorry about that. One more lesson learned on our quest to ultimate quality!

Re: Docker 0.7 runs on all Linux distributions

#53

Post by Nux »

EL6 users (RHEL, CentOS, SL), I've just learned Docker is now in EPEL (testing for now, but will hit release soon):

yum --enablerepo=epel-testing install docker-io

PS: make sure you have "cgconfig" service running

Re: Docker 0.7 runs on all Linux distributions

#55

Post by hsuresh »

shykes wrote: post #30
neals wrote: post #9

I see docker come around every now and then here. I'm a smalltime developer shop, small team, small webspps. What can docker do for me? Can this reduce the time it takes me to put up and Ubuntu installation on Digital Ocean? Is this more for larger companies ?

Yes, Docker should be able to help you. It is definitely not just for large companies. Docker can help you streamline your development and deployment process across all the machines, from the development laptop to the production server. The result should be that your development environment is easier to setup and replicate, more similar to production, and easier to customize as you evaluate new tools, hosting provide…

I just went through the Getting started tutorial. Thanks for a great intro into Docker. Is this tutorial open sourced too? What would really help is, include a few lines on how the commands can be used in real world.

Edit: The website/tutorial is open source too. https://github.com/dotcloud/www.docker.io

Re: Docker 0.7 runs on all Linux distributions

#56

Post by [deleted] »

shykes wrote: post #13
andyl wrote: post #6

Earlier quoted context omitted.

does this mean that docker will run on 32 bit systems ?

Not yet, but that's coming very soon. We've been artificially limiting the number of architectures supported to limit the headache of managing cross-arch container images. We're reaching the point where that will no longer be a problem - meanwhile the Docker on Raspberry Pi community is growing restless and we want to make them happy :)

[deleted]

Re: Docker 0.7 runs on all Linux distributions

#57

Post by pradn »

shykes wrote: post #19
Sprint wrote: post #14

I looked at it several times but never really got it. Can I use Docker to isolate different servers (think http, xmpp, another http on another port) on a server so that if one of them was exploited, the attacker would be constrained to inside the container? Or is it "just" of a convenient way to put applications into self-contained packages?

It's both. Everyone using docker benefits from the "software distribution" feature. Some people using docker also benefit from the security and isolation features - it depends on your needs and the security profile of your application. Because the underlying namespacing features of the kernel are still young, it's recommended to avoid running untrusted code as root inside a container on a shared machine. If you drop…

Which namespacing features are still young? Is it still possible to evade LXC as described in this post? http://blog.bofh.it/debian/id_413

Re: Docker 0.7 runs on all Linux distributions

#58

Post by shykes »

linvin wrote: post #50
zrail wrote: post #10

Earlier quoted context omitted.

Fixed. Sorry about that.

Also, when writing about -p option (e.g. -p 8080:8080), you could choose different port numbers for container and host, so we know the latter is for the host and former is for container.

That's a good point, thanks. Note: the author and HN poster are 2 different people, but evidently we both check comments :)

Re: Docker 0.7 runs on all Linux distributions

#59

Post by TkTech »

k__ wrote: post #49
shykes wrote: post #13

Earlier quoted context omitted.

Not yet, but that's coming very soon. We've been artificially limiting the number of architectures supported to limit the headache of managing cross-arch container images. We're reaching the point where that will no longer be a problem - meanwhile the Docker on Raspberry Pi community is growing restless and we want to make them happy :)

So the software in a container runs on the host-OS and there is no extra OS installed in the container?

This is correct. It uses features of the kernel and modern filesystems for efficient isolation.
Post reply on HN