[Pkg-nginx-maintainers] Bug#821114: nginx: Please use KillSignal=SIGQUIT in systemd service

[Christos Trochalakis]

On Thu, Nov 10, 2016 at 10:42:36PM +0100, Michael Biebl wrote:
>On Tue, 8 Nov 2016 11:20:45 +0200 Christos Trochalakis
><yatiohi at ideopolis.gr> wrote:
>> On Fri, Apr 15, 2016 at 06:54:55PM +0200, Laurent Bigonville wrote:
>> >Package: nginx
>> >Version: 1.6.2-3
>> >Severity: normal
>> >User: pkg-systemd-maintainers at lists.alioth.debian.org
>> >
>> >Hi,
>> >
>> >Wouldn't it be better to use KillSignal=SIGQUIT in the .service file
>> >rather than using this hack?
>> >
>> >ExecStop=-/sbin/start-stop-daemon --quiet --stop --retry QUIT/5 --pidfile /run/nginx.pid
>> >
>> >Is it necessary really necessary to send QUIT, then TERM and then KILL?
>> >
>>
>> By using KillSignal=SIGQUIT systemd would forcibly (SIGKILL) nginx after
>> the timeout is reached.
>>
>> SIGQUIT triggers graceful shutdown so it waits for all existing client
>> connections to terminate. If for example you have websocket or SSE long
>> running clients you will hit the timeout. In such cases we don't want
>> systemd to SIGKILL nginx.
>>
>> The current solution fallbacks to SIGTERM that forces systemd to close
>> existing clients and terminate.
>>
>>
>
>Would
>ExecStop=/bin/kill -QUIT $MAINPID
>
>work?
>This would first send SIQUIT to the main process, after TimeoutStopSec=
>it would send SIGTERM to all remaining processes and after another
>TimeoutStopSec=, SIGKILL.
>Is this the behaviour you want?
>
>It feels a bit more systemdish to me then involving start-stop-daemon
>
>

If I remember correctly that wont do it. Systemd expects the ExecStop=
command to block until the service is stopped, or it fallbacks to
SIGTERM. According to the systemd.service(5):

> After the commands configured in this option are run, all processes
> remaining for a service are terminated according to the KillMode=
> setting.

I remember testing this a while back and decided to use
start-stop-daemon which has the ability to block until the service is
stopped:
https://anonscm.debian.org/cgit/collab-maint/nginx.git/commit/?id=caee1c2a