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I have an application that uses the jetty maven plugin "run-forked" goal that I need to dockerize. What happens is that maven starts, the container exists only for about 10 seconds and then dies when maven exits after it forks the child JVM process.

I have investigated many options. One option that I thought might work is to set "waitForChild" to true and then do something like this:

ENTRYPOINT [ "/entrypoint.sh" ]
CMD [ "jetty:run-forked > /tmp/log 2>&1" ]

But, though this keeps maven running, the image does not build, because Docker waits for a SIGTERM.

If you are wondering why I need to use jetty:run-forked, it is because the code requires a static linked library that needs a JVM.

I am ready to throw in the towel, because this seems impossible ...

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Christopher Johnson
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1 Answers1

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I'm not entirely sure about your java set up, but a neat trick that works is something like this:

In your dockerfile, add a custom script like so:

COPY myscript.sh /bin/myscript.sh # Remember to make this executable!

then edit your ENTRYPOINT to reflect that:

ENTRYPOINT ["/bin/myscript.sh"]

Your myscript.sh could look a little something like this:

#!/bin/bash

# Run Java/mvn commands here
...
jetty:run-forked > /tmp/log 2>&1

# Throw in a shell command that simply executes forever
tail -f /dev/null

This will ensure your container keeps running even after your jetty/mvn stuff spawns another process and quits, because it is no longer PID 1 within the container, the myscript.sh shell script is. This shell script continues to run forever because of the tail -f.

ffledgling
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