Currently, ipcluster can be run in the foreground or in the background using the --daemonize option. However, this daemonizing appears to happen immediately at startup. So if I run something like:

#!/bin/bash

ipcluster-3 start -n 4 --daemonize
python3 <<EOF
from ipyparallel import Client
client = Client()
print(client[:])
EOF

then the script fails because the engines are not available (ipyparallel.error.NoEnginesRegistered). Inserting a sleep 5 will fix it because the engines will have started, but this is basically a guess-and-hope-it-works approach.

It would be really nice if ipcluster would wait to background itself until after the engines have started instead.