Add --unique-app-id parameter

[philipp94831]

No description provided.

[torbsto]

I would slightly prefer a new parameter in streams that lets you set the consumer group instead of the flag, and I really don't see why it would break anything.

[torbsto]

I think the default should be false if your goal is that it is non-breaking

[philipp94831]

New helm chart should have it as default but old apps can still use new chart. We did a similar thing for optimizeLeaveGroupBehavior

[torbsto]

I guess it would clutter the API even more and lead to confusion together with getUniqueAppId(), but I feel like we will need to call it elsewhere

[philipp94831]

Hm, this method does the validation whenever Kafka properties are created. So getUniqueAppId() should still return the correct result unless a user explicitly overrides the method and it returns null. I don't think this will ever happen

[torbsto]

And I think we need a test for this method

[philipp94831]

Will add tests, just wanted to have your thoughts first

[torbsto]

@raminqaf @philipp94831 Like I said above, I'd prefer using a separate argument for the app id and not reusing the autoscaling one. See feature/application-id-param...feature/helm-app-id for how I imagine it could work

[philipp94831]

@raminqaf @philipp94831 Like I said above, I'd prefer using a separate argument for the app id and not reusing the autoscaling one. See feature/application-id-param...feature/helm-app-id for how I imagine it could work

I feel like having two parameters is more confusing. Then we should document it well and probably deprecat the old way of configuring it

[torbsto]

I would be fine with deprecating it, but I'm not sure if there might be a situation in which someone wants to use KEDA but not set the consumer group via Helm.
I also added this check so that we fail as early as possible:

streams-bootstrap/charts/streams-app/templates/scaled-object.yaml

Lines 2 to 4 in b86810e

	{{- if and (.Values.streams.appId) (.Values.autoscaling.consumerGroup) -}}
	{{- fail "streams.appId and autoscaling.consumerGroup are mutually exclusive. You can use use streams.appId for apps 2.17.0+. If you don't want to set your app id via Helm or you're using an older version, but still want to use KEDA autoscaling, set autoscaling.consumerGroup" -}}
	{{- end -}}

But I agree that we should also document it properly in the values.yaml and README.md

[philipp94831]

@raminqaf @philipp94831 Like I said above, I'd prefer using a separate argument for the app id and not reusing the autoscaling one. See feature/application-id-param...feature/helm-app-id for how I imagine it could work

There is also this annotation we should not forget about https://github.com/bakdata/streams-bootstrap/blob/master/charts/streams-app/templates/deployment.yaml#L20

[philipp94831]

Closing in favor of #243