[Kubernetes] backup before a container is terminated

[win5923]

Incorporate backup functionality before the termination of a container due to API requests or management events such as liveness/startup probe failure, preemption, resource contention, and others.

Choices

• Add backup before a container is terminated.
• Addressing Add lifecycle preStop stop hook and probes to Kubernetes #243 (comment)
• Refer to Add Daily Reboot Cronjob (K8s) #206 (comment)

Test instructions

1. I haven't tested it yet. I'll conduct the test in a few days.

Checklist before requesting a review

• I have performed a self-review of my code
• I've added documentation about this change to the README.
• I've not introduced breaking changes.

[anthr76]

Considering this would need RBAC (and kubectl in the container) it would be probably be better to just execute a script in the container

[win5923]

Considering this would need RBAC (and kubectl in the container) it would be probably be better to just execute a script in the container

I just realized that I am running inside a pod, so there is no need to execute kubectl. Thank you for your advice.
But I haven't come up with a better method to determine the pod is unhealthy.

[win5923]

Perhaps a livenessProbe for the RCON port can be configured, but I'm not sure about the correlation between the server and RCON.

   livenessProbe: 
      tcpSocket:
        port: 25575
      initialDelaySeconds: 30
      periodSeconds: 60

[anthr76]

Good point 👍🏼 I think we just address the probe(s) in another PR as that may be tricky. I'll try to think about a solution. This looks good! Should we also add a /Shutdown to the rcon commands?

[win5923]

After a liveness probe failure, the pod will be restarted. I think it may not be necessary. I might conduct a test using Minikube in the next few days.

[thijsvanloef]

@win5923 Just give me a headsup when it is ready to merge :)

[win5923]

@win5923 Just give me a headsup when it is ready to merge :)

Done!

[bobbyrward]

This doesn't work. exec only takes a command not a command and args

[win5923]

This doesn't work. exec only takes a command not a command and args

Oh, you're right. I forgot to save before applying. No wonder I was able to apply successfully.
I will resubmit a new pull request to correct this error. Thank you very much.