[ENHANCEMENT] As a User I can extend the default application configuration

[ChrisKujawa]

Describe the use case:

We have recently added a way to configure the applications with configuration. The problem with that is that it completely replaces the existing defaults (set in the template).

Describe the enhancement/feature:

I would like to define an additional configuration, without the need to also configure the default again. Especially this might not be possible if I depend on the helm chart like the benchmark-helm
, as some values are dynamic related to the release-name.

See related slack thread

Desired outcome and acceptance tests:

I can configure for example Zeebe via:

zeebe:
  extraConfiguration:
    zeebe.gateway.monitoring.enabled: "true"
    zeebe.gateway.threads.managementThreads: "1"
    zeebe.broker.experimental.consistencyChecks.enablePreconditions: "true"
    zeebe.broker.experimental.consistencyChecks.enableForeignKeyChecks: "true"
    zeebe.broker.executionMetricsExporterEnabled: "true"
    zeebe.broker.data.diskUsageCommandWatermark: "0.8"
    zeebe.broker.data.diskUsageReplicationWatermark: "0.9"
    # Configure index suffix with hour pattern, so we create every hour a new index
    # such that ILM can clean it up quickly
    zeebe.broker.exporters.elasticsearch.args.index.indexSuffixDatePattern: "yyyy-MM-dd_HH"

and this is taken into account by Zeebe. Together with the defaults, like elasticsearch configurations

[ChrisKujawa]

Solution could be to merge application.yaml somehow or we are able to configure a separate file and configure SPRING to load separate configuration, see https://camunda.slack.com/archives/C03UR0V2R2M/p1723034182870359?thread_ts=1722947834.149849&cid=C03UR0V2R2M

:fyi2: I found a workaround for now, using SPRING_CONFIG_ADDITIONALLOCATION I can mount a separate config with a different name that gets also passed to broker and gateway.
See camunda/zeebe-benchmark-helm@35daa48
But of course it would be cool if this could be supported out-of-the-box from the platform chart.

[aabouzaid]

We plan to work on it in this task #2186
Not sure if we will use merge or just append to the config.

[jessesimpson36]

It was decided in
https://github.com/camunda/product-hub/issues/2697

that we would rely on the functionality of post-renderers and document them rather than support extra configuration options via a new values.yaml option:

https://docs.camunda.io/docs/next/self-managed/deployment/helm/configure/add-extra-manifests/#manipulate-manifests

Closing as wontfix