Nomad: Release official Docker image of nomad

[jhmartin]

Please consider releasing a blessed Docker image of nomad on Dockerhub, similar to Vault and Consul

[diptanu]

@jhmartin We don't recommend running Nomad in docker containers because Nomad clients interact with the host OS quite a bit so running in a container doesn't allow it to get the full view of the host.

I am closing this issue but please feel free to ask more questions or the problems you are trying to solve.

[jhmartin]

I'm looking at running this on something like RancherOS / CoreOS where the operating model is 'everything is a container', so running nomad outside of a container is difficult to orchestrate. Even a very highly privileged container would get around the issue.

[diptanu]

@jhmartin Nomad needs to be able to introspect the available resources on a machine like disk, cpu and memory resource usage, bind mount host directories to containers, etc which simply aren't possible while running in a container.

[jhmartin]

@diptanu thank you for the clarification.

[luckyraul]

@diptanu

What about server role? Using as a scheduler only? Can it be dockerized?

[jhmartin]

@diptanu /proc can be mounted into a container under an alternate path which should get around inspecting most of the state of the server.

[alxark]

@diptanu i believe you know nomad better than me, but according to docker hub (https://hub.docker.com/search/?isAutomated=0&isOfficial=0&page=1&pullCount=0&q=nomad&starCount=0) users need it. I'm using nomad in docker with docker driver and everything looks fine. I think you should create official builds for nomad. Also it will be great to see build of consul+nomad for fast deployment (currently i'm installing consul to djenriquez/nomad image). This will improve installation process and more users will be able to try it.

[groggemans]

@diptanu It's now a year later, could you please review this again?

It would be nice to have an official image, the demand is there (1M+ pulls of the most popular community image)

Container based OS's have become more popular since the initial review of the idea too. Technically this should be possible as @jhmartin pointed out.

[derek-adair]

On the flip-side... it seems like a waste to replace a project w/ 1M+ Downloads.

And for what its worth I dont really see the difference between Vagrant up and Docker up. Vagrantfile is clearly listed in the installation guide.

[tommyalatalo]

On the flip-side... it seems like a waste to replace a project w/ 1M+ Downloads.

And for what its worth I dont really see the difference between Vagrant up and Docker up. Vagrantfile is clearly listed in the installation guide.

It's not really a waste to have the creator of the software offer an official release of it, instead of relying on a community member to keep updating the image.

I think this should be looked over once more as well, the image could be used for CD purposes as well, to just run nomad jobs in a CI/CD environment without having to install nomad in the environment.

[the-maldridge]

Tacking on my 2 cents here. Nomad needs to introspect the machine state to know how much it is allowed to assign and use, not how much is actually there.

This is an important difference as I as the local system administrator may have made a choice that nomad is not permitted to use the entire machine, only a very large slice of it.

[martinffx]

I'll add my 2 cents...

The nomad client and server are part of the same executable. I understand why you would not want to run a nomad server in docker. But most CI tools these days are docker based and I do want to use nomad client as part of my CI. Having an official docker image for that would be nice.