Anyway to get the ID of processes created by Supervisord?

As of supervisor version 3 you can use the supervisorctl pid <name> command to list pids of managed processes:

supervisorctl pid programname

Use supervisorctl pid all to get a newline-separated list of pids of all managed processes.

For older supervisord versions, you are stuck with supervisord status, but with a little awk, sed and paste massaging, you can extract those pids to be acceptable as input to other commands:

echo `bin/supervisorctl status | grep RUNNING | awk -F' ' '{print $4}' | sed -e 's/,$//' | paste -sd' '`

would list all pids of running programs as a space-separated list. Replace echo with a kill -HUP command to send them all the SIGHUP signal, for example.

You can now do the following:

sudo supervisorctl pid all
sudo supervisorctl pid myprogramname