JavaExec does not exit properly when interrupted with container logging enabled and no output from a container

[tony-schellenberg]

Long running JavaExec processes are left running when used with docker compose if the following happens:

1. The process is long running
2. The docker-compose stanza in gradle attempts to log the container output using one of
   • captureContainersOutput
   • captureContainersOutputToFile
3. The container doesn't actually produce any output
   • Ran into this with the memcached container specifically

The following demonstrates the issue:

1. Execute ./gradlew run to start
   • Web server that is long running
   • Has capture output statements in the docker-compose stanza
   • Uses memcached in the associated docker-compose file
2. Inspect the process list
   • See that the process is running
3. Interrupt gradle with ctrl-c
4. Inspect the process list again
   • Notice that the process is still running
   • The process doesn't exit

Not sure how much of this is relevant but adding it in case it's useful:

• O/S is Ubuntu 18.04
• OpenJDK 11 from the O/S
• Happens on the command line and when invoked with IntelliJ
• Interestingly, doesn't seem to be an issue when gradle/the application is run in debug mode

I'm happy to provide more detail or information as required.

[augi]

Hello, unfortunately, there is no way (no API available) how to handle this situation with long-running processes correctly. You could execute Gradle with --no-daemon so the JVM should be turned off right after your build - then it should work as expected. This is actually the same as running in debug mode.

[tony-schellenberg]

I just want to make sure my comment was clear. It's specifically an issue when the container does not produce any output and captureContainerOutput* is used in the docker-compose stanza. It works fine otherwise.

For example, if I switch from the memcached container to the mysql one (which does produce output), I can interrupt gradle and it will correctly shut down the main process.

[tony-schellenberg]

Not sure if this is helpful but here's a small demo project with a readme that goes through the steps. demo.tar.gz