Instrument http add on operator

[elieserr]

Added instrumentation for promethues compatible endpoints and otel.
Added tests and e2e tests.

I went forward this ways as I was trying to get familiar with codebase. Happy to go in any direction reviewers advise.

Checklist

• Commits are signed with Developer Certificate of Origin (DCO)
• Changelog has been updated and is aligned with our changelog requirements
• Any necessary documentation is added, such as:
  • README.md
  • The docs/ directory
  • The docs repo

Part of #965

[elieserr]

Hi folks, trying to get some eyes here but not really sure who to tag, thanks for any pointer in advance
@JorTurFer @rickbrouwer @zroubalik tagging you 3 since helped me with previous unrelated PR kedacore/keda#6990

[JorTurFer]

Thanks a lot for the contribution!

[zroubalik]

@elieser1101 could you please check those failing e2e tests?

Execution of tests/checks/interceptor_otel_tracing/interceptor_otel_tracing_test.go, has failed after 3 tries

https://productionresultssa7.blob.core.windows.net/actions-results/26098fe6-b81f-40fd-a510-2a1de926e4ca/workflow-job-run-ede9479a-8054-5533-84ce-0cba19fe1088/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-09-18T16%3A06%3A24Z&sig=UYhSwGEyITYO9%2F4%2B6TwjmNd%2FI9WZOIUDfJonhMAyaUg%3D&ske=2025-09-19T02%3A15%3A03Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-09-18T14%3A15%3A03Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-09-18T15%3A56%3A19Z&sv=2025-11-05

[elieserr]

I was able to reproduce the error in my local env. Was because of misconfig on go.mod. Also I rebased latest changes from main so this should work. lets see how e2e goes.

@zroubalik @wozniakjan @JorTurFer for workflow approval.

[elieserr]

e2e went good on previous run, so fixing lints and some broken links from docs

[Copilot]

Pull Request Overview

This PR adds instrumentation for Prometheus-compatible endpoints and OpenTelemetry (OTEL) metrics to the KEDA HTTP Add-on operator. The implementation provides monitoring capabilities for HTTP scaled objects through both metrics collection methods.

• Added metrics collection infrastructure with Prometheus and OTEL exporters
• Implemented HTTP scaled object count tracking in the operator controller
• Added comprehensive end-to-end tests for both metrics collection methods

Reviewed Changes

Copilot reviewed 21 out of 22 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
operator/metrics/	New package containing metrics collection infrastructure with Prometheus and OTEL exporters
operator/controllers/http/httpscaledobject_controller.go	Updated controller to track HTTP scaled object metrics with thread-safe map
operator/controllers/http/config/config.go	Added metrics configuration structure with environment variable parsing
operator/main.go	Integrated metrics collectors initialization into main function
tests/checks/operator_*_metrics/	Comprehensive E2E tests for both Prometheus and OTEL metrics
docs/	Updated documentation with metrics configuration instructions
config/	Added Kubernetes manifests for metrics service and E2E test configurations

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

When the map entry already exists, the code calls RecordDeleteHTTPScaledObjectCount before RecordHTTPScaledObjectCount, which could lead to incorrect metrics if the namespace changed. This logic appears to be attempting to handle namespace changes, but it's unclear and potentially buggy.

Suggested change

	metrics.RecordDeleteHTTPScaledObjectCount(scaledObject.Namespace)
	// Record deletion for the old namespace before updating
	metrics.RecordDeleteHTTPScaledObjectCount(metricsData.namespace)