start script exits with errors. npm v7? docker-compose?

[joemaller]

Something changed with how the npm run start (webpack serve) process is exiting. It now throws an error which prevents the poststart script from being called.

I still think it's primarily related to the change in signal propagation in npm v7, briefly touched upon in npm#2124.

But there are also slight changes in how docker-compose is working, especially as Docker migrates away from docker-compose cli towards the new compose command.

Finally, the webpack-dev-server v4 beta release notes mention a new setupExitSignals option which might have something to do with this?.

Too many variables with too many new releases, so I'm shelving this for now (2021-08). Will check back after webpack-dev-server ships v4 -- which looks like it's going to be a lot of work based on how much they're changing.

2021-08-15T20_13_32_302Z-debug.log

[joemaller]

Upgraded tooling to webpack devserver v4 and set setupExitSignals, still getting the errors. ideasonpurpose/docker-build@0d70e04

[joemaller]

Try running commands using exec form instead of shell form, See note here: https://github.com/Haufe-Lexware/docker-style-guide/blob/master/Dockerfile.md#use-exec-form-rather-than-shell

You MUST write CMD and ENTRYPOINT statements using the Exec-form.
Using the shell form would effectively trigger a call to /bin/sh -c with the command and parameters you specified.

As a result, when you use docker stop or docker kill the POSIX signal will only be sent to the container process running as PID 1, and if that process is /bin/sh rather than the underlying process you started and /bin/sh doesn't forward signals to any child processes you won't be able to gracefully stop the process.