Run local built container on swarm

[aanm]

I know this is probably something hard to do, but will (or is it right now?) be possible to run a docker image built on the host machine to be ran on a swarm machine? I just figure this out when I tried to run the simplest demo from compose and swarm, where one of the containers is built on my machine.

[aluzzardi]

You can either:

• Push the container somewhere, then you'll be able to run it, or
• docker build on Swarm (instead of the local machine) then docker run using image affinities (no need of image affinities once we address Proposal: docker build + docker create without image affinities #743)

[aanm]

@aluzzardi Where does swarm stores the image made by docker build? I mean, is it possible the built result would end up on a node and docker run will be addressed to a different node?

[aluzzardi]

@aanm Yes, very likely. docker build uses the same scheduling as docker run, so it will end up on a machine depending of your filters and strategy. docker run will likely try to run on a different node.

Right now, you can solve this by using image affinities:

docker build -t foo .
docker run -e affinity:image==foo foo

The former will build an image on the cluster while the latter will schedule a run and force it to be on a machine that has the foo image.

#743 will do that for you automatically

[jasw]

Thanks, that helped me.

[aluzzardi]

@aanm The affinity is not required anymore in master (and on the upcoming 0.4.0) thanks to a PR by @jimmyxian

[aanm]

@aluzzardi Thanks for the heads up! Can you tell me the PR number?

[aluzzardi]

Proposal is #743 and implementation #971