Rework config map's

[Zelldon]

Reworks the zeebe config maps which are deployed with the services/applications.

• Remove the startup scripts from the gateway config map
• Replace most of the code from the zeebe startup script with kubernetes dependent environment variables
  • inspired by https://github.com/camunda-community-hub/camunda-cloud-operator/blob/main/operator/controllers/zeebe_controller.go
  • Why: To have everything in one place and for better maintainability most of the env vars are set in the statefulset manifest.
• Initial contact points are calculated with helm template range (inspired by Loop over a range from N to {{.Values.someCount}} helm/helm#1055)

I tried it out and the following is calculated correctly:

$ k logs test-zeebe-0

+ env
...
ZEEBE_BROKER_CLUSTER_NODEID=0
ZEEBE_BROKER_CLUSTER_CLUSTERNAME=test-zeebe
ZEEBE_BROKER_CLUSTER_INITIALCONTACTPOINTS=test-zeebe-0.test-zeebe.zell-helm-test.svc.cluster.local, test-zeebe-1.test-zeebe.zell-helm-test.svc.cluster.local, test-zeebe-2.test-zeebe.zell-helm-test.svc.cluster.local,
...
K8S_NAMESPACE=zell-helm-test
K8S_SERVICE_NAME=test-zeebe
K8S_NAME=test-zeebe-0

\cc Maybe interesting for you @Sijoma (I can still not request a review from you)

related to #124

[Sijoma]

Seems way cleaner 👍 . I wonder what it would take to have a dynamic discovery mechanism?

Would this also be a PR for our "other" repo? 😉

[Zelldon]

Seems way cleaner  . I wonder what it would take to have a dynamic discovery mechanism?

Yeah would also be cool :) unfortunately currently not possible.

Yes I just wanted to check with you how you like it 😄 and then I wanted to create a PR their 😬

Thanks for the review @Sijoma ❤️