Hey there,
I tinkered around with a ssh-less openmpi and I was wondering if it could be implemented in a nicer way. http://qnib.org/2016/03/31/dssh/
I just used -mca plm_rsh_agent /opt/qnib/src/dssh with a rather simple script to use docker exec:
#!/bin/bash
REMOTE_HOST=$1
shift
set -x
docker -H unix:///var/run/docker.sock exec -i -u ${USER} ${REMOTE_HOST} $@
Cheers Christian