What signal does upstart/initctl use to restart a job?

Question

What signal will upstart/initctl use to restart a job? Furthermore, is there any way to specify that SIGHUP should be used?

Alternately, is there a way to define a custom reload command that will send a SIGHUP? Or do I need to go outside of upstart to do that?

Answer 1

What signal will upstart/initctl use to restart a job?

SIGTERM

strace -fp `pgrep cron` 2> ~/strace &
initctl restart cron

cat ~/strace

rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {0x804a280, [CHLD], SA_RESTART}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({60, 0}, {57, 153662204})     = ? ERESTART_RESTARTBLOCK (To be restarted)
--- SIGTERM (Terminated) @ 0 (0) ---
Process 2275 detached

Furthermore, is there any way to specify that SIGHUP should be used?

Use: initctl reload

Alternately, is there a way to define a custom reload command that will send a SIGHUP?

Use: initctl reload

Or do I need to go outside of upstart to do that?

Use initctl reload or kill/killall -HUP