Add serviceName Field to OpenTelemetryCollector CRD for StatefulSet Deployments

[vignesh-codes]

Description: Add support for custom service names in StatefulSet headless services

This PR fixes the handling of service names for StatefulSet mode in the OpenTelemetry Collector operator:

• Adds ability to specify custom service names via spec.serviceName field for sts
• When running in StatefulSet mode and no service name is specified, defaults to <name>-headless
• Maintains existing behavior for non-StatefulSet modes
• Ensures TLS secret names follow the service naming pattern

Link to tracking Issue(s): 4029

Testing: Added new test cases in statefulset_test.go for statefulset creation with custom and default service names:

• Test default headless service name generation for StatefulSet mode
• Test custom service name handling for sts

Documentation:

[pavolloffay]

Could you please add assert here https://github.com/open-telemetry/opentelemetry-operator/blob/6d2f18b0ac0303aff2b904c2de76296cea60fbf9/tests/e2e/smoke-statefulset/00-assert.yaml

[vignesh-codes]

Could you please add assert here https://github.com/open-telemetry/opentelemetry-operator/blob/6d2f18b0ac0303aff2b904c2de76296cea60fbf9/tests/e2e/smoke-statefulset/00-assert.yaml

@pavolloffay I have added them

[vignesh-codes]

@pavolloffay @iblancasa requesting for workflow approvals and reviews

[swiatekm]

@vignesh-codes running make update should fix the CI failure.

[vignesh-codes]

I imagined this feature working a bit differently. Rather than letting the user rename the Service (which in and out of itself isn't that useful), it should let them provide the name of a Service they created themselves. This how setting serviceAccount currently works, but we can always create the headless Service regardless. @open-telemetry/operator-approvers what do you think we should do here?

I don't have any complaints about the fix setting the default as the headless Service, so maybe we can make that a separate PR?

Cool! i made the make update command and pushed the commit. Let me know

[rewt]

this is my current working config from the collector helm chart

  nameOverride: "dev-opentelemetry-backend-collector"
  fullnameOverride: "dev-opentelemetry-backend-collector-headless"

here is how the collector chart currently functions https://github.com/open-telemetry/opentelemetry-helm-charts/blob/09a02cb2dc1fe2c0e7e0ee51c2fe9c6a95ddc807/charts/opentelemetry-collector/templates/statefulset.yaml#L16

It'd be nice for a similar option with the OpenTelemetryCollector CR when mode: statefulset

[swiatekm]

this is my current working config from the collector helm chart

  nameOverride: "dev-opentelemetry-backend-collector"
  fullnameOverride: "dev-opentelemetry-backend-collector-headless"

here is how the collector chart currently functions https://github.com/open-telemetry/opentelemetry-helm-charts/blob/09a02cb2dc1fe2c0e7e0ee51c2fe9c6a95ddc807/charts/opentelemetry-collector/templates/statefulset.yaml#L16

It'd be nice for a similar option with the OpenTelemetryCollector CR when mode: statefulset

That's already how it functions. The Service name is based on the OpenTelemetryCollector's metadata.name.

[swiatekm]

@vignesh-codes looks good to me now! Could you resolve the lint failure? Then we should be good to merge.

[vignesh-codes]

@iblancasa Waiting for your review and approval. Thanks