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name: review description: Repository-specific guidance for the AI code review agent reviewing this repo user-invocable: true disable-model-invocation: true

Code review guidance

This is Traefik Proxy (Go), a cloud-native reverse proxy and load balancer. The reviewer already fixes the role, the tools, the severity definitions, the finding mechanics and the output format; this guidance is additive and must not restate them. Record findings only with the severities the reviewer accepts: CRITICAL, IMPORTANT, MINOR, QUESTION.

Review in this priority order, and keep the bar high at every level.

Security

• Validate authentication, authorization and trust boundaries at every boundary crossing.
• Trace untrusted input through to dangerous sinks (exec, SQL, file I/O, template rendering).
• No hardcoded passwords, tokens or API keys; no secrets or sensitive data in logs.

Correctness

• Nil dereferences, race conditions, off-by-one errors, inverted conditions, unhandled edge cases.
• Errors are wrapped with fmt.Errorf in gerund form, e.g. fmt.Errorf("unmarshalling data: %w", err), and never silently dropped with _.
• Resource leaks: unclosed connections, leaked goroutines, contexts not propagated or cancelled.
• context.Context must be the first argument of every function that accepts one, named ctx.
• Do not use context.Background() in request paths — propagate the context from the caller.
• Custom context keys must be unexported struct types (type myKey struct{}), never bare strings or integers.
• Changes must not blur the static/dynamic configuration boundary: static configuration is read at startup only; dynamic configuration is produced by providers at runtime. Code that reads dynamic config at startup, or stores static config in a runtime struct, is a correctness bug.
• New dynamic configuration options must be replicated everywhere the option's structure is duplicated. In particular, a field added to a pkg/config/dynamic type has a mirror in the Kubernetes CRD types under pkg/provider/kubernetes/crd/traefikio/v1alpha1; the new field must be added there and wired through the CRD-to-dynamic conversion in pkg/provider/kubernetes/crd/kubernetes.go. A dynamic option that is not exposed on the duplicated CRD struct is a bug.

Breaking changes

• Flag breaking changes to exported Go APIs and to CRD schemas under traefik.io/v1alpha1.
• Flag configuration changes that affect existing deployments.

Performance

• Superlinear algorithms where linear suffices, and avoidable allocations or I/O, but only in hot paths where it measurably matters.

Maintainability

• Interfaces: prefer single-method, -er suffix, declared at the usage site.
• Idiomatic Go: early returns and guard clauses, the standard library (slices, maps, cmp) over premature abstraction or third-party helpers, grouped import ordering, exported items with a doc comment starting with the item name.
• Comments must explain why, not what; the code already says what. Every comment must end with a period.
• Tests: new behaviour needs tests using testify/assert and testify/require; use require for preconditions that must stop the test, assert for independent checks. Tests must be table-driven with t.Parallel(). Blackbox testing (package x_test) is preferred. Do not add verbose message arguments to assert/require calls — the test name provides the context.

Do not flag

• Generated code: files matching zz_generated*.go, everything under pkg/provider/kubernetes/crd/generated/, and webui/static/.
• Test mocks: files matching mock_*.go or *_mock.go.
• //nolint: directives — they are intentional.
• Integration test fixtures under integration/fixtures/ — Docker-dependent behaviour cannot be verified statically.
• Patterns already used consistently across the codebase.

Before claiming a change is unsafe, check how the changed functions are used elsewhere in the repository: the call sites decide.