Mailman has a number of runner subprocesses which perform long-running tasks such as listening on an LMTP port, processing REST API requests, or processing messages in a queue directory. In normal operation, the mailman command is used to start, stop and manage the runners. This is just a wrapper around the real master watcher, which handles runner starting, stopping, exiting, and log file reopening.
>>> from mailman.testing.helpers import TestableMaster
Start the master in a sub-thread.
>>> master = TestableMaster()
>>> master.start()
There should be a process id for every runner that claims to be startable.
>>> from lazr.config import as_boolean
>>> startable_runners = [conf for conf in config.runner_configs
... if as_boolean(conf.start)]
>>> len(list(master.runner_pids)) == len(startable_runners)
True
Now verify that all the runners are running.
>>> import os
# This should produce no output.
>>> for pid in master.runner_pids:
... os.kill(pid, 0)
Stop the master process, which should also kill (and not restart) the child runner processes.
>>> master.stop()
None of the children are running now.
>>> import errno
>>> for pid in master.runner_pids:
... try:
... os.kill(pid, 0)
... print('Process did not exit:', pid)
... except OSError as error:
... if error.errno == errno.ESRCH:
... # The child process exited.
... pass
... else:
... raise