PMM-15188 Add e2e coverage for MySQL TLS monitoring across key rotation

[theTibi]

Adds an encryption feature-build scenario that guards PMM-15188: adding a MySQL service with TLS, rotating the encryption key twice, and asserting that (1) MySQL monitoring keeps working after rotation and (2) the stored agents.mysql_options tls_cert/tls_key do not grow across rotations.

Before the fix, each rotation re-encrypted these columns during the decrypt phase, stacking an encryption layer per cycle until pmm-agent failed with "tls: failed to find any PEM data in certificate input".

[coderabbitai]

Walkthrough

Changes

MySQL TLS rotation validation

Layer / File(s)	Summary
TLS monitoring rotation regression test codeceptjs-e2e/tests/encryption/encryption_test.js	Adds a retryable end-to-end scenario that provisions TLS credentials, registers MySQL monitoring, validates metrics, performs two encryption-key rotations, and checks that certificate and key lengths remain unchanged.

Mergeability Score: 🔵 Low · up to 4d059

The added coverage is mergeable with owner awareness, but the randomized service name can collide during retries or parallel runs and cause the test to validate stale monitoring data.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the PMM-15188 objective and the added end-to-end coverage for MySQL TLS monitoring during encryption-key rotation.
Description check	✅ Passed	The description directly explains the TLS scenario, repeated key rotations, monitoring checks, and certificate-length assertions covered by the changes.
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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Inline comments:
In `@codeceptjs-e2e/tests/encryption/encryption_test.js`:
- Line 111: Update the serviceName generation in the encryption test to use a
collision-resistant unique suffix instead of the 99-value random range, ensuring
parallel runs and retries cannot select an older matching service or stale
mysql_up samples.

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Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ea84ec0c-3830-43e7-ac1d-be5d9465453e

📥 Commits

Reviewing files that changed from the base of the PR and between 3bfd21d and 4d059b6.

📒 Files selected for processing (1)

• codeceptjs-e2e/tests/encryption/encryption_test.js

🔗 Linked repositories identified

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

• percona/pmm-qa (manual)
• percona/pmm (manual) → reviewed against branch claude/pmm-15188-gjny9e instead of the default branch