ohwgiles/laminar

Reload config file, not restart on SIGHUP

KAction opened this issue · 3 comments

KAction commented

Conventionally, unix daemons reload their config files on sighup. Laminar does otherwise -- it terminates.
Any change to get it to follow the convention?

I just stumbled upon it when I got job that refreshes SSL certificates and sighup all daemons on multiple systems. One of them was the system that was running laminar itself. I worked around by excluding Laminar, but having all daemons behave same way would be awesome.

Thank you again for your work!

ohwgiles commented

Conventionally, unix daemons reload their config files on sighup.

While common, this is definitely not universal. Apache, for instance, uses SIGUSR1 to reload config.

Laminar does otherwise -- it terminates.

Of course, this is the default action for SIGHUP.

sighup all daemons

Out of interest, how do you implement this? How do you know which processes are "daemons", and avoid e.g. sending HUP to a currently running job (child process) of laminard? Seems a safer option would be to explicitly list the processes which need to be reloaded when certs are updated....

All that being said, ignoring SIGHUP is a reasonable thing for a daemon process to do, so laminard could do that. It does not need a "reload config" action.

KAction commented

sighup all daemons

Out of interest, how do you implement this? How do you know which processes are "daemons", and avoid e.g. sending HUP to a currently running job (child process) of laminard? Seems a safer option would be to explicitly list the processes which need to be reloaded when certs are updated....

I use runit(8) supervision suite. Every daemon managed by runsvdir(8) has directory in /service, so you can do mass operations with sv hup /service/*. Or sv hup /service/nginx-*, using flexibility of shell patterns.
=> http://smarden.org/runit/sv.8.html

All that being said, ignoring SIGHUP is a reasonable thing for a daemon process to do, so laminard could do that. It does not need a "reload config" action.

Fair enough, although I would write 'Laminar don't have config to reload, SIGHUP is ignored' on stderr on sighup. That would have saved me from half-an-hour to hour of debugging today.