Supposing my container is named fluentd, I'd expect this command to reload the config:
sudo docker kill -s HUP fluentd
Instead it kills the container.
Seems there is some spawning of a few processes from the entrypoint:
PID USER TIME COMMAND
1 root 0:00 {entrypoint.sh} /usr/bin/dumb-init /bin/sh /bin/entrypoint.sh /bin/sh -c fluentd -c /fluentd/etc/${FLUENTD_CONF} -p /fluentd/pl
5 root 0:00 /bin/sh /bin/entrypoint.sh /bin/sh -c fluentd -c /fluentd/etc/${FLUENTD_CONF} -p /fluentd/plugins $FLUENTD_OPT
13 fluent 0:00 /bin/sh -c fluentd -c /fluentd/etc/${FLUENTD_CONF} -p /fluentd/plugins $FLUENTD_OPT
14 fluent 0:00 {fluentd} /usr/bin/ruby /usr/bin/fluentd -c /fluentd/etc/fluentd.conf -p /fluentd/plugins
16 fluent 0:00 {fluentd} /usr/bin/ruby /usr/bin/fluentd -c /fluentd/etc/fluentd.conf -p /fluentd/plugins
Tried HUPping from inside the container pid 13 and it seems to work.
Docker is sending the signal to the entrypoint. If I inspect the State.Pid, I see 4450. Here's the host ps:
root 4450 4432 0 18:30 ? 00:00:00 /usr/bin/dumb-init /bin/sh /bin/entrypoint.sh /bin/sh -c fluentd -c
/fluentd/etc/${FLUENTD_CONF} -p /fluentd/plugins $FLUENTD_OPT
root 4467 4450 0 18:30 ? 00:00:00 /bin/sh /bin/entrypoint.sh /bin/sh -c fluentd -c /fluentd/etc/${FLUENTD_CONF} -p /fluentd/plugins $FLUENTD_OPT
ubuntu 4475 4467 0 18:30 ? 00:00:00 /bin/sh -c fluentd -c /fluentd/etc/${FLUENTD_CONF} -p /fluentd/plugins $FLUENTD_OPT
ubuntu 4476 4475 0 18:30 ? 00:00:00 /usr/bin/ruby /usr/bin/fluentd -c /fluentd/etc/fluentd.conf -p /fluentd/plugins
ubuntu 4478 4476 0 18:30 ? 00:00:00 /usr/bin/ruby /usr/bin/fluentd -c /fluentd/etc/fluentd.conf -p /fluentd/plugins
Any ideas how do reload the conf without a custom script to find the correct process to HUP?