Example of a Salt execution module that "fires and forgets" a command that may not ever return correctly.

server.py

from subprocess import Popen

def start_server():
    cmd_str = 'coffee /tmp/app/app.coffee'
    proc = Popen([cmd_str], shell=True,
        stdin=None, stdout=None, stderr=None, close_fds=True)
    return cmd_str