fix: Add .cluster.local to no_proxy environment variable

[olivergondza]

What type of PR is this?

Uncomment only one /kind line, and delete the rest.
For example, > /kind bug would simply become: /kind bug

/kind bug

/kind cleanup
/kind failing-test
/kind enhancement
/kind documentation
/kind code-refactoring

What does this PR do / why we need it:

Since #1223, the operator is adding trailing dots to local hostnames for fasted DNS resolution. This has caused a regression because they are not matching the default openshift no_proxy config (it contains .cluster.local, but not .cluster.local.), forcing legitimate internal communication to use a proxy server.

This change is making sure that the entry with trailing dot is added as well.

Have you updated the necessary documentation?

• Documentation update is required by this PR.
• Documentation has been updated.

Which issue(s) this PR fixes:

Fixes #?

Test acceptance criteria:

• Unit Test
• E2E Test

How to test changes / Special notes to the reviewer:

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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• controllers/util/util.go

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📝 Summary

Summary by CodeRabbit

• Bug Fixes
  • Improved proxy configuration so NO_PROXY includes both .cluster.local and .cluster.local. entries when needed.
  • Prevented duplicate entries from being added to existing NO_PROXY values.
  • Updated proxy configuration validation to cover these scenarios.

Walkthrough

Proxy environment handling now adds .cluster.local. when absent. Shared utilities and Argo CD deployment handling preserve existing NO_PROXY entries without duplication. Tests update expected values and cover the new behavior.

Changes

Proxy environment handling

Layer / File(s)	Summary
Shared proxy utility update controllers/util/util.go	ProxyEnvVars appends .cluster.local. when absent and preserves other proxy variables.
Argo CD proxy integration and validation argocd-operator/controllers/argocd/deployment.go, argocd-operator/controllers/argocd/deployment_test.go, argocd-operator/controllers/argocd/applicationset_test.go	proxyEnvVars appends .cluster.local. without duplication. Tests update expected values and verify existing NO_PROXY entries.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 13 functions across 4 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title identifies the no_proxy change and the relevant cluster.local entry. It omits the trailing dot, but it remains directly related to the main change.
Description check	✅ Passed	The description clearly explains the regression and the addition of .cluster.local. to no_proxy, and it mentions the unit test.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[coderabbitai]

Actionable comments posted: 1

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• 🪄 Fix CodeRabbit comments on this PR

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Inline comments:
In `@controllers/util/util.go`:
- Line 250: Update the addToNoProxy call to add the trailing-dot
".cluster.local." entry, ensuring ProxyEnvVars bypasses the proxy for
trailing-dot cluster hostnames while preserving the existing non-trailing-dot
entry.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Organization UI (inherited)

Review profile: CHILL

Plan: Enterprise

Run ID: 691b74c6-0bbf-47bd-93c1-899de6473115

📥 Commits

Reviewing files that changed from the base of the PR and between 72e3e4b and 38669e0.

📒 Files selected for processing (4)

• argocd-operator/controllers/argocd/applicationset_test.go
• argocd-operator/controllers/argocd/deployment.go
• argocd-operator/controllers/argocd/deployment_test.go
• controllers/util/util.go

🔗 Linked repositories identified

CodeRabbit considers these linked repositories for cross-repo context during reviews:

• argoproj-labs/argocd-operator (manual)

Included review availability: Your plan provides up to 12 included reviews per hour; 11 remain after this review.

[svghadi]

/lgtm

[olivergondza]

/test v4.14-kuttl-sequential

[openshift-ci]

New changes are detected. LGTM label has been removed.

[openshift-ci]

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