Hi, I got a kotlin server app that is deployed in pods (k8s). In some cases, k8s can send SIGTERM / ...

# server

[Laurent Thiebaud]

Hi, I got a kotlin server app that is deployed in pods (k8s). In some cases, k8s can send SIGTERM / SIGKILL signals to kill my app.
What is the good way, in Kotlin, to gracefully shutdown (close all connections...)?
Is there better than the java way?

Runtime.getRuntime().addShutdownHook(myShutdownHook);

[simon.vergauwen]

I build a small SuspendApp { } variant on top of runBlocking that does exactly this on top of Structured Concurrency.

So, if you receive a SIGTERM or SIGINT it will cancel the CoroutineScope, and it'll block the shutdown thread until the entire program is finished (CoroutineScope.join).

This allows you to run finalisers, such as committing offsets to Kafka, stop(500, 500) any network engine, clean-up, etc.

Side-note: it lives under the Arrow-kt umbrella, but it only has KotlinX Coroutines as a dependency.

https://github.com/arrow-kt/suspendapp

[Emil Kantis]

You should watch Simon’s excellent video on the topic as well. I can’t find it now sadly

[simon.vergauwen]

I think you're referring to this one @Emil Kantis,

https://www.youtube.com/watch?v=A69_t_oEP_E▾

Thanks ☺️