Koa: Koa v1 - process.on('SIGINT', ...) causes Koa to never release port. How to detect app exit?

[rally25rs]

I am writing my first Koa app, and need to close my DB connection and do some other cleanup before the application exits.

I tried adding the code:

function cleanup() {
    console.log('Closing...');
}

process.on('SIGINT', cleanup);
process.on('SIGTERM', cleanup);

And if I press clrl-c on the console, the app does exit and my cleanup function is called, but a process continues to run and keep the port in use, so I can't re-run my app. The cleanup function does nothing at the moment, it just does a console.log() statement and nothing else.

Attempting to re-run the app just results in the error:

Error: listen EADDRINUSE :::8888

If I comment out the process.on() lines, then the app does release its port correctly.

---

Is there a better/correct way to detect app exit and perform cleanup?

[rally25rs]

Update: The ports are eventually released after some length of time. Perhaps it waits for the socket timeout?

Using process.on('exit', ...) instead seems to resolve this issue.

[rally25rs]

Update2: Strangely Nodejs was running old code (I could comment out entire files and re-run node, and it would still execute fine as if my code had not been edited) so my previous comment turned out to not be true.

process.on('exit', cleanup);

the cleanup function is never called. It seems like this event is never triggered if ctrl-c is pressed on the console (Windows. Haven't tried on OSX yet).

[dead-horse]

SIGTERM and SIGINT have default handlers on non-Windows platforms that resets the terminal mode before exiting with code 128 + signal number. If one of these signals has a listener installed, its default behavior will be removed (Node.js will no longer exit).

maybe you should add process.exit(1) in your cleanup function.

[rally25rs]

It looks like this code works:

function cleanup() {
    console.log('Closing...');
    process.exit(1);
}

process.on('SIGINT', cleanup);
process.on('SIGTERM', cleanup);

Thanks for the help @dead-horse