fix(adapter): start pprof server when profiling is enabled

[theakshaypant]

Fixes #9007

Proposed Changes

The eventing adapter framework creates and configures a ProfilingServer but never calls ListenAndServe, so the profiling port is never bound even when runtime-profiling is set to enabled in the observability ConfigMap. Start the server conditionally based on the initial config, consistent with the adapter's static observability config model.

Pre-review Checklist

• At least 80% unit test coverage
• E2E tests for any new behavior
• Docs PR for any user-facing impact
• Spec PR for any new API feature
• Conformance test for any change to the spec

Release Note

Profiling via the observability ConfigMap (`runtime-profiling: enabled`) now works correctly for components using the eventing adapter framework. Previously the profiling server was never started and port 8008 was never bound, making pprof endpoints unreachable.

Docs

Testing
My testing might have been limited to the use-case I was trying when I first ran into the original issue.
Covered three test scenarios:

1. Nothing happens when config-observability has profiling disabled
2. Enable profiling in the cm - able to access the profiling endpoints on port 8008.
3. Enable profiling in the cm and explicitly set env on my deployment PROFILING_PORT=8090 - able to access the profiling endpoints on port 8090.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: theakshaypant / name: Akshay Pant (f81324b)

[knative-prow]

Welcome @theakshaypant! It looks like this is your first PR to knative/eventing 🎉

[knative-prow]

Hi @theakshaypant. Thanks for your PR.

I'm waiting for a knative member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work.

Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[creydr]

/ok-to-test

[theakshaypant]

I went through the logs from some of the failed tests and see error messages around TLS which I would guess is more of an infra issue rather than related to the PR changes. 🤔

[creydr]

I went through the logs from some of the failed tests and see error messages around TLS which I would guess is more of an infra issue rather than related to the PR changes. 🤔

Oh yes. Seems it needs #9009

[theakshaypant]

I went through the logs from some of the failed tests and see error messages around TLS which I would guess is more of an infra issue rather than related to the PR changes. 🤔

Oh yes. Seems it needs #9009

Rebased with 9009 changes.

[creydr]

/test unit-tests

[theakshaypant]

Apologies for the noise, added pprof server shutdown on context cancellation

$ go test -race -count=1 ./pkg/adapter/v2/ -timeout 60s
ok      knative.dev/eventing/pkg/adapter/v2     2.644s

[creydr]

Thanks for fixing this @theakshaypant
/lgtm
/approve

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: creydr, theakshaypant

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [creydr]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 51.06%. Comparing base (263a3a5) to head (f81324b).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/adapter/v2/main.go	66.66%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9008      +/-   ##
==========================================
+ Coverage   51.04%   51.06%   +0.01%     
==========================================
  Files         409      409              
  Lines       21996    21996              
==========================================
+ Hits        11228    11232       +4     
+ Misses       9905     9900       -5     
- Partials      863      864       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[knative-prow]

@theakshaypant: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
reconciler-tests_eventing_main	f81324b	link	unknown	/test reconciler-tests

Your PR dashboard.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.