Using Docker under Slurm

Sometimes it is convenient to ask Slurm to run your job in a docker container. This is just fine, however, you will need to fully test your job in a docker container beforehand (on mustard or emerald, for example) to see how much RAM and CPU resources it requires, so you can accurately describe in your slurm job submission file how many resources it needs.

You can run your container on mustard then look at 'top' to see how much RAM and CPU it needs.

You also will need to be aware that you will need to pull your docker image from a registry, like DockerHub or Quay. And you should also run you docker container with the '--rm' flag, so the container cleans itself up after running. So your workflow would look something like this:

1: Pull image from DockerHub
2: docker run --rm docker/welcome-to-docker

Optionally you can clean up your image as well, but only if you don't have many jobs using that image on the same node. For example, if I wanted to remove the image laballed "weiler/mytools":

$ docker image ls
REPOSITORY                          TAG                    IMAGE ID       CREATED         SIZE
weiler/mytools                     latest                 be6777ad00cf   19 hours ago    396MB
somedude/tools                     latest                 9b1d1f6fbf6f   3 weeks ago     607MB

$ docker image rm be6777ad00cf

We also have auto-cleaning scripts running that will delete any containers and images that were created/pulled more than 7 days ago. This inlcudes the cluster nodes and also the phoenix head node itself. If you need a place to have your images/containers remain longer than that, please put them on mustard,emerald, crimson or razzmatazz.