[AGENTONB-2759] Use k8s informer for helm metadata

[swang392]

What does this PR do?

• Modifies the helm metadata forwarder to use kubernetes informers instead of listing and caching.
• Uses workqueue as the event handler for informer events
• Adds a ticker (set to 1 min) that regularly sends metadata for all relevant releases at the time
• Update tests
• More details / rationale on implementation here

Motivation

What inspired you to submit this pull request?

Additional Notes

Anything else we should know when reviewing?

Minimum Agent Versions

Are there minimum versions of the Datadog Agent and/or Cluster Agent required?

• Agent: vX.Y.Z
• Cluster Agent: vX.Y.Z

Describe your test plan

• install operator via helm, with debug logging enabled

❯ helm install datadog-operator datadog/datadog-operator --set image.doNotCheckTag=true --set image.repository=operator --set logLevel="debug"  --set installCRDs=true --set clusterName=sarah-dev --set image.tag=metadata-58

• install the datadog chart with operator disabled:

datadog:
  operator:
    enabled: false

• Check for startup log messages from the helm metadata forwarder. If you have multiple revisions (secrets/configmaps) for a helm chart on your cluster, you will see log messages of skipped older revisions. For example:

{"level":"DEBUG","ts":"2026-01-13T19:04:46.259Z","logger":"metadata.helm","msg":"Starting worker","workerID":0}
{"level":"DEBUG","ts":"2026-01-13T19:04:46.360Z","logger":"metadata.helm","msg":"Updated release snapshot","key":"default/datadog-operator","revision":11,"chart":"datadog-operator"}
{"level":"DEBUG","ts":"2026-01-13T19:04:46.366Z","logger":"metadata.helm","msg":"Updating to newer revision","key":"default/datadog-operator","old":11,"new":12}
{"level":"DEBUG","ts":"2026-01-13T19:04:46.367Z","logger":"metadata.helm","msg":"Sending metadata to URL","url":"https://app.datadoghq.com/api/v1/metadata"}
{"level":"DEBUG","ts":"2026-01-13T19:04:46.382Z","logger":"metadata.helm","msg":"Received HTTP response for metadata","release":"datadog-operator","status_code":202}
{"level":"DEBUG","ts":"2026-01-13T19:04:46.382Z","logger":"metadata.helm","msg":"Updated release snapshot","key":"default/datadog-operator","revision":12,"chart":"datadog-operator"}
{"level":"DEBUG","ts":"2026-01-13T19:04:46.389Z","logger":"metadata.helm","msg":"Updating to newer revision","key":"default/datadog-operator","old":12,"new":17}

• Update the datadog chart. You should immediately see logs documenting the update:

{"level":"DEBUG","ts":"2026-01-13T20:38:51.436Z","logger":"metadata.helm","msg":"Updating to newer revision","key":"default/dd","old":1,"new":2}
{"level":"DEBUG","ts":"2026-01-13T20:38:51.437Z","logger":"metadata.helm","msg":"Sending metadata to URL","url":"https://app.datadoghq.com/api/v1/metadata"}
{"level":"DEBUG","ts":"2026-01-13T20:38:51.453Z","logger":"metadata.helm","msg":"Updated release snapshot","key":"default/dd","revision":2,"chart":"datadog"}

• In the next log from the ticker, verify that two charts (datadog, datadog operator) get sent:

{"level":"DEBUG","ts":"2026-01-13T20:38:13.216Z","logger":"metadata.helm","msg":"Ticker: sending all Helm release snapshots"}
{"level":"DEBUG","ts":"2026-01-13T20:38:13.216Z","logger":"metadata.helm","msg":"Sending metadata to URL","url":"https://app.datadoghq.com/api/v1/metadata"}
{"level":"DEBUG","ts":"2026-01-13T20:38:13.233Z","logger":"metadata.helm","msg":"Sending metadata to URL","url":"https://app.datadoghq.com/api/v1/metadata"}
{"level":"DEBUG","ts":"2026-01-13T20:38:13.251Z","logger":"metadata.helm","msg":"Ticker: sent Helm release snapshots","sent":2,"errors":0}

• Uninstall the datadog chart. Check that the deletion event was registered by the informer, and that the next ticker send does not include the datadog chart.

{"level":"INFO","ts":"2026-01-13T20:38:57.004Z","logger":"metadata.helm","msg":"Deleted release snapshot for release","releaseKey":"default/dd"}
{"level":"DEBUG","ts":"2026-01-13T19:10:46.259Z","logger":"metadata.helm","msg":"Ticker: sending all Helm release snapshots"}
{"level":"DEBUG","ts":"2026-01-13T19:10:46.259Z","logger":"metadata.helm","msg":"Sending metadata to URL","url":"https://app.datadoghq.com/api/v1/metadata"}
{"level":"DEBUG","ts":"2026-01-13T19:10:46.278Z","logger":"metadata.helm","msg":"Received HTTP response for metadata","release":"datadog-operator","status_code":202}
{"level":"DEBUG","ts":"2026-01-13T19:10:46.278Z","logger":"metadata.helm","msg":"Ticker: sent Helm release snapshots","sent":1,"errors":0}

Checklist

• PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• PR has a milestone or the qa/skip-qa label
• All commits are signed (see: signing commits)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 17.64706% with 154 lines in your changes missing coverage. Please review.
✅ Project coverage is 38.08%. Comparing base (b4b6e01) to head (79a443f).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/controller/utils/metadata/helm_metadata.go	17.93%	150 Missing and 1 partial ⚠️
cmd/main.go	0.00%	3 Missing ⚠️

❌ Your patch status has failed because the patch coverage (17.64%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2488      +/-   ##
==========================================
- Coverage   38.09%   38.08%   -0.02%     
==========================================
  Files         299      299              
  Lines       25182    25226      +44     
==========================================
+ Hits         9594     9608      +14     
- Misses      14853    14878      +25     
- Partials      735      740       +5     

Flag	Coverage Δ
unittests	38.08% <17.64%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
cmd/main.go	6.62% <0.00%> (ø)
pkg/controller/utils/metadata/helm_metadata.go	31.88% <17.93%> (-0.02%)	⬇️

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