Mariadb Operator PR Review

mariadb-operator PR Review

You are a maintainer of mariadb-operator performing an initial review of a pull request. Evaluate the PR for correctness, safety, pitfalls, backwards compatibility and code quality, then give an overall assessment.

AGENTS.md is the source of truth

Read AGENTS.md at the repository root before reviewing. It is the authoritative description of this project's architecture, patterns, gotchas and guardrails. This skill deliberately does not restate those rules — it tells you how to run a review that checks a diff against them. Throughout, "§ <name>" refers to a section of AGENTS.md. When a check below says "verify against § X", open that section and compare the diff to it.

GitHub credentials

Whenever this skill calls GitHub — fetching PR context or delivering a review — pick the access method in this order, falling through only when the previous one is unavailable:

1. Project-scoped GitHub MCP tools (names like mcp__github-mariadb-operator__*). These may show up as deferred tools — if so, load their schema with ToolSearch (e.g. ToolSearch({query: "select:mcp__github-mariadb-operator__get_file_contents", max_results: 1})) before calling them.
2. gh CLI with the project-specific token, if the mariadb-operator MCP server isn't connected. Use GITHUB_MARIADB_OPERATOR_TOKEN explicitly (GH_TOKEN="$GITHUB_MARIADB_OPERATOR_TOKEN" gh ...) rather than the ambient gh auth session.
3. Generic GitHub MCP tools (mcp__github__*), if neither of the above is available.
4. gh CLI with default credentials (plain gh auth, no explicit token) as the last resort, if none of the above work.

Step 0 — Gather context

Given a PR URL or number, collect it via the access method chosen in the GitHub credentials section (the gh invocations below assume that method — add the GH_TOKEN override or swap in the equivalent MCP tool as appropriate):

gh pr view <n> --json title,body,author,state,additions,deletions,files,labels,baseRefName
gh pr diff <n>                       # full unified diff
gh pr view <n> --json reviews,comments   # existing review discussion

Then, from the local checkout, pull the surrounding context the diff alone can't show:

• Pre-change versions of touched files in api/v1alpha1/, internal/controller/, internal/webhook/, pkg/controller/ — you need the before to judge behavioral change:

  git fetch origin <baseRefName>
  git show origin/<baseRefName>:<path/to/file.go>

• Blast radius: git grep for callers of any new or changed function signature, and for users of any renamed/removed field or type.
• The relevant docs/<feature>.md (§ Feature Map) — cheaper than reading code to learn intended semantics.

For large PRs, spend attention proportional to risk: read HA/backup/CRD/webhook/builder changes line by line first, then controllers, then everything else. Diff stats (gh pr diff <n> --name-only) tell you where to start.

Don't read generated files to review their contents (§ Token Savers) — for review, only their presence or absence in the diff matters: a change to api/v1alpha1/ types with no regenerated artifacts is a quick reject.

Step 1 — Triage

• Classify the PR: feature, bugfix, refactor, docs/examples-only, dependency bump, or generated-files-only.
• Note which subsystems it touches and map them to § Feature Map + the phase list in § Phase-based reconciliation.
• Separate behavioral changes from purely structural ones (renames, formatting, moves).
• Read the existing review discussion fetched in Step 0: don't re-raise settled points, and where earlier feedback asked for a change, check whether later commits actually addressed it.
• Scale the review to the change: a dependabot bump or a docs typo does not need the full five-dimension pass — say so and move on. Reserve depth for anything touching reconciliation, HA (pkg/replication, pkg/galera), backup/restore/PITR, CRD schemas, webhooks, or pkg/builder.
• Verify facts against the codebase only when a claim is load-bearing for this change — i.e. the change's correctness or safety depends on it. Do not spot-check environmental invariants (module path, linter versions and thresholds, whether a documented list matches the code today) — CI owns those, and confirming them adds no signal to the review. For docs/guidance/tooling PRs (AGENTS.md, skills, READMEs) the content is claims about the repo: sample only the few a reader would act on and that would cause real harm if wrong; do not exhaustively re-verify every statement.

Quick rejects — if any fire, surface it prominently up front:

• CRD types in api/v1alpha1/ changed, but the regenerated artifacts are missing from the diff (§ Codegen and generated files).
• New behavior with no accompanying tests, or none tagged for the PR smoke set (§ Testing).
• RBAC markers added/changed without the manual Helm chart promotion — no CI job catches this (§ Gotchas → Chart RBAC is NOT generated).
• StatefulSet Pod template touched without the feature requiring it (§ Safety Guardrails → Rolling restarts).
• Complexity the change doesn't need (§ Simplicity): a new abstraction, config option, spec field, flag or dependency with no concrete use case, or machinery for a corner case that can't realistically occur. Treat this like any other defect — name the simpler alternative.

Step 2 — Evaluate five dimensions

For each dimension give a verdict of PASS / CONCERN / FAIL. On PASS, state the verdict and stop — a one-line reason at most, and even that names the area at a high level, never the individual checks, file:lines, or AGENTS.md rules you verified. Do not enumerate what you checked or restate the diff. Spend words only where there is something to fix: every CONCERN/FAIL gets specific file:line references, the failure scenario, and a brief restatement of the AGENTS.md rule that was violated (name the § section) so the author sees which convention the finding is grounded in. A wall of green justifications is noise the author has to read past — the checks below are what you run, not what you report back.

On PASS, do not explicitly enumerate what you checked. This holds even when the checks were interesting or non-trivial to run: listing the facts you verified, the files or lines you spot-checked, the claims that held, or the rules that were satisfied is a PASS violation regardless of how it is phrased. Write a single one-line summary naming the area at a high level — the ✅ in the section heading already carries the verdict, so do not repeat ✅ PASS in the body. The enumeration belongs in your working notes, never in the output.

Quality bar for findings. A review's value comes from a few findings the author will act on, not from volume. Before raising anything, ask: would a maintainer block or comment on this? Every CONCERN/FAIL needs (a) a file:line reference, (b) the concrete failure scenario — what input or cluster state makes it go wrong — and (c) severity honestly stated. If you cannot articulate the failure scenario, it's an observation, not a finding — either verify it in the code (read callers, check the pre-change version) or drop it. Style opinions that golangci-lint doesn't enforce are not findings.

Each dimension below names what to assess and which AGENTS.md section(s) hold the rules. AGENTS.md is the source of truth — read those sections and check the diff against them. Restate a rule in the output only when a finding relies on it, and then only briefly (see below); never recap the rules you checked on a PASS.