Adjust termination handling

- use `SIGQUIT` as stop signal for the container
- set `process_control_timeout` to 5 seconds for PHP-FPM

This should make 502 errors less likely when scaling down or doing
rolling updates.

Author: kdambekalns

Dockerfile

@@ -39,6 +39,10 @@ RUN export FLOWNATIVE_LOG_PATH_AND_FILENAME=/dev/stdout \
 USER 1000
 EXPOSE 9000 9001
 
+# terminate with SIGQUIT which is handled gracefully by php-fpm
+# contrary to SIGTERM which terminates php-fpm immediately.
+STOPSIGNAL SIGQUIT
+
 WORKDIR ${PHP_BASE_PATH}
 ENTRYPOINT [ "/entrypoint.sh" ]
 CMD [ "run" ]

root-files/opt/flownative/php/etc/php-fpm.conf.template

@@ -7,6 +7,11 @@ pid = ${PHP_TMP_PATH}/php-fpm.pid
 ; the shell running php-fpm.sh, so we can wait for it with "wait":
 daemonize = no
 
+; tell the child processes to wait for 5s before executing the signal
+; received from the parent process, to make the php-fpm container
+; terminate gracefully:
+process_control_timeout = 5
+
 [www]
 
 access.log = ${PHP_FPM_ACCESS_LOG_PATH}