malcyon
commented
3 years ago I see that the health check for the graylog image is using the REST API for the Docker health check:
https://github.com/Graylog2/graylog-docker/blob/4.0/health_check.sh#L96
But I don't think the forwarder is listening on any network ports. At least, I don't see any in the container:
root@0dd04a31debb:/# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 18:22 pts/0 00:00:00 tini -- /forwarder-entrypoint.sh /bin/bash
root 7 1 6 18:22 pts/0 00:00:11 /usr/local/openjdk-8/bin/java -Xms1g -Xmx1g -XX:-OmitStackTraceInFastThrow -jar /usr/share/gr
root 129 0 0 18:23 pts/1 00:00:00 /bin/bash
root 375 129 0 18:23 pts/1 00:00:00 bash
root 743 375 0 18:25 pts/1 00:00:00 ps -ef
root@0dd04a31debb:/# netstat -anlp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 172.17.0.2:46284 34.203.170.187:13302 ESTABLISHED 7/java
tcp 0 0 172.17.0.2:52336 199.232.10.132:80 TIME_WAIT -
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node PID/Program name Path
unix 2 [ ] STREAM CONNECTED 1883982 7/java I think Docker can restart on failure the way it's configured now, but it's definition of "failure" is the process exiting.
@danotorrey What's a good way to check the health of the forwarder?
we should add a health check to the forwarder image to give users the ability to have this forwarder restarted automatically on failure.
This need to be added to the image like:
https://github.com/Graylog2/graylog-docker/blob/4.0/docker/oss/Dockerfile#L132-L137
and should check if the process in the image is running proper.