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

Docker interactive tutorial

blog.docker.io

Post reply on HN
Print view View original

31–40 of 48 posts

Re: Docker interactive tutorial

#31

Post by cheeseprocedure »

tootie wrote: post #16
csears wrote: post #14

Earlier quoted context omitted.

Regarding who is supposed to use it... If you like deploying your apps to a Platform-as-a-Service (PaaS) like Heroku, Google AppEngine, or DotCloud, but wanted to run it on your own infrastructure, then Docker could be for you! It's designed to be a key building block for anyone who wants to create their own PaaS-like service or environment. Why would you need your own PaaS? You might have unique security requirement…

So I'm used to configuring stuff by hand, and now I see a lot of buzz around docker, vagrant, chef, puppet, salt and they seem like glorified shell scripts. Am I missing something?

These tools let you focus on the bigger picture instead of the nitty-gritty.

Docker and Vagrant are convenient for building (and distributing) consistent environments on top of (potentially wildly) different software or hardware platforms. Docker has a ton of other tricks up its sleeve (one example is "layers:" http://docs.docker.io/en/latest/terms/layer/).

Chef/Puppet/Salt/et al. are configuration management tools which enable programmatic definition of infrastructure. The key point is: you define how the system should look, not the specific steps on how to get there. Abstraction layers (management of files/users/packages/services/etc.) provided by the CM tool shield you from a nightmare of permutations, corner cases, and platform-specific options; it'll just enforce a given configuration regardless of local changes.

Having a central source of truth for systems configuration is a gamechanger in itself; your configuration directives or applications can query (or update) your configuration management database, which enables some very cool automation with very little effort. Then there's the community: for any given stack, there's probably a well-documented, well-tested Chef cookbook or Puppet manifest to build it, instantly plugging you into a rich experience base.

Yes, one could script all of this from scratch, but I'm not sure why one would.

Re: Docker interactive tutorial

#33

Post by wmf »

ams6110 wrote: post #29
zhemao wrote: post #3

Haha, I had a good laugh upon hearing that Docker cannot run inside of itself. Is this an LXC limitation? Clearly the solution was to run Docker inside of KVM inside of Docker. But seriously, nice job. I haven't used docker yet because I want to play around with the standard lxc utilities first. But this is pretty awesome.

Would there be a useful reason to actually do this (run Docker in Docker), or is it more just a novelty?

I'd like to give each tenant a container and let them run Docker app containers within that.

Re: Docker interactive tutorial

#34

Post by e12e »

shykes wrote: post #27
seiji wrote: post #25

Why is the docker hype machine cranked up to 11?

Hi seiji, I'm the author of Docker. There is hype around docker, for sure. The optimist in me likes to think that it's because people find the project useful and are excited about the possibilities of containers in general - which I believe are huge. Me and the dotCloud team have been working on container technology since 2008. For a long time it felt like preaching in the desert - mostly because it required exotic p…

Could you share some thoughts (or links) on the differences between LXC and linux-vserver? I played a little bit with that, and it seemed to promise "true jails" for Linux -- and LXC seems to be a natural successor -- any comment of what we've gained/lost from the "transition"?

I'd also love to hear what people think about the relationship between freebsd+jails, solaris+zones and Linux+LXC/docker and/or if it would make sense to modularize the back-end so that "docker" (as in the daemon/management tools) would work for maintaining jails and/or zones as well?

It'd be fun to be able to run docker+LXC under GNU Debian/Linux, and docker+jails under GNU Debian/kFreebsd (and ditto for the Debian-like/Ubunut-based solaris distros)... Maybe not useful, but interesting...

Re: Docker interactive tutorial

#36

Post by anonymousDan »

e12e wrote: post #34
shykes wrote: post #27

Earlier quoted context omitted.

Hi seiji, I'm the author of Docker. There is hype around docker, for sure. The optimist in me likes to think that it's because people find the project useful and are excited about the possibilities of containers in general - which I believe are huge. Me and the dotCloud team have been working on container technology since 2008. For a long time it felt like preaching in the desert - mostly because it required exotic p…

Could you share some thoughts (or links) on the differences between LXC and linux-vserver? I played a little bit with that, and it seemed to promise "true jails" for Linux -- and LXC seems to be a natural successor -- any comment of what we've gained/lost from the "transition"? I'd also love to hear what people think about the relationship between freebsd+jails, solaris+zones and Linux+LXC/docker and/or if it would m…

Ditto, I'd like to hear a bit more about the security related strengths and weaknesses of docker and its alternatives.

Re: Docker interactive tutorial

#37

Post by shykes »

e12e wrote: post #34
shykes wrote: post #27

Earlier quoted context omitted.

Hi seiji, I'm the author of Docker. There is hype around docker, for sure. The optimist in me likes to think that it's because people find the project useful and are excited about the possibilities of containers in general - which I believe are huge. Me and the dotCloud team have been working on container technology since 2008. For a long time it felt like preaching in the desert - mostly because it required exotic p…

Could you share some thoughts (or links) on the differences between LXC and linux-vserver? I played a little bit with that, and it seemed to promise "true jails" for Linux -- and LXC seems to be a natural successor -- any comment of what we've gained/lost from the "transition"? I'd also love to hear what people think about the relationship between freebsd+jails, solaris+zones and Linux+LXC/docker and/or if it would m…

> Could you share some thoughts (or links) on the differences between LXC and linux-vserver?

vserver, lxc and openvz were 3 competing projects to add process-level isolation to the linux kernel. We used all 3 of them extensively (the ancestor of docker was based on vserver, then ported to openvz, then finally to lxc). They all had pros and cons, but in the end the only meaningful difference is that lxc got merged upstream, and the others didn't.

> would make sense to modularize the back-end so that "docker" (as in the daemon/management tools) would work for maintaining jails and/or zones as well?

Absolutely. That is the goal, and starting with 0.8 Docker's architecture will be modular enough to support it.

See this blog post for details: http://blog.docker.io/2013/08/getting-to-docker-1-0/

Re: Docker interactive tutorial

#38

Post by kinleyd »

I've been playing a bit with Docker and found I couldn't get the kernel option to work (the linux-aufs_friendly kernel just wouldn't work on my Arch setup). However, that forced me to the option of using vagrant to set up a vm with docker configured and I found that great - I recommend this option over playing with your kernel.

I'm a long time virtualbox user but had never played with headless vms and never realized how easy that is with vagrant. Additionally, using vagrant to get a coreos vm running, with docker all set up, was pretty cool. So far I'm finding the payload of the vms rather heavy (with the os overhead), but I haven't really got down to setting up individual docker app containers. I'm looking forward to that, and even more to what could lie ahead for this space: vagrant, coreos, docker, chef/puppet all look to making a very promising convergence.

Re: Docker interactive tutorial

#39

Post by mateuszf »

kinleyd wrote: post #38

I've been playing a bit with Docker and found I couldn't get the kernel option to work (the linux-aufs_friendly kernel just wouldn't work on my Arch setup). However, that forced me to the option of using vagrant to set up a vm with docker configured and I found that great - I recommend this option over playing with your kernel. I'm a long time virtualbox user but had never played with headless vms and never realized…

Probably it won't help you, but Docker is working on my Arch with linux-aufs_friendly kernel.

Re: Docker interactive tutorial

#40

Post by kinleyd »

mateuszf wrote: post #39
kinleyd wrote: post #38

I've been playing a bit with Docker and found I couldn't get the kernel option to work (the linux-aufs_friendly kernel just wouldn't work on my Arch setup). However, that forced me to the option of using vagrant to set up a vm with docker configured and I found that great - I recommend this option over playing with your kernel. I'm a long time virtualbox user but had never played with headless vms and never realized…

Probably it won't help you, but Docker is working on my Arch with linux-aufs_friendly kernel.

I suspect it must have something to do with my set up. My first suspicion was my nvidia drivers (304xx) but I recall not even being able to boot in console mode. I'll give it another shot later but for the moment vagrant's doing a fine job putting it all together.
Post reply on HN