Add metadata package

[piceri]

Refactored metadata logic to its own metadata package and added testing

[Copilot]

Pull request overview

Refactors Kubernetes annotation/ownership metadata aggregation out of the controller into a dedicated internal/metadata package, and adds unit tests around extraction and aggregation behavior.

Changes:

• Introduces internal/metadata.Aggregator to traverse pod owner references and collect runtime risks + custom tags.
• Adds focused tests for metadata extraction rules (limits, validation) and ownership traversal (chain, cycles, missing owners, fetch errors).
• Updates the controller and cmd/deployment-tracker wiring to use the new aggregator instead of directly using the metadata client.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
internal/metadata/metadata.go	New metadata aggregation implementation (BFS traversal, extraction of runtime risks and tags).
internal/metadata/metadata_test.go	New unit tests covering extraction rules and owner-chain aggregation behavior.
internal/controller/controller.go	Removes inline metadata aggregation and injects a metadata aggregator dependency.
cmd/deployment-tracker/main.go	Instantiates the Kubernetes metadata client + new aggregator and passes it to the controller.

Comments suppressed due to low confidence (2)

internal/controller/controller.go:72

• controller.New now accepts a podMetadataAggregator, but the constructor doesn't validate it is non-nil. If a nil is passed, processEvent will panic when calling c.metadataAggregator.AggregatePodMetadata. Consider returning an error from New when metadataAggregator is nil (fail fast) to avoid a runtime nil dereference.

// New creates a new deployment tracker controller.
func New(clientset kubernetes.Interface, metadataAggregator podMetadataAggregator, namespace string, excludeNamespaces string, cfg *Config) (*Controller, error) {
	// Create informer factory
	factory := createInformerFactory(clientset, namespace, excludeNamespaces)

	podInformer := factory.Core().V1().Pods().Informer()

internal/metadata/metadata.go:200

• This debug log for duplicate tags includes both existing_value and new_value. For the same reason as above (annotation values may be sensitive), consider omitting raw values from logs and logging only the tag key (and possibly lengths).

			if _, exists := aggPodMetadata.Tags[tagKey]; exists {
				slog.Debug("Duplicate tag key found, skipping",
					"object_name", obj.GetName(),
					"kind", obj.Kind,
					"tag_key", tagKey,
					"existing_value", aggPodMetadata.Tags[tagKey],
					"new_value", tagValue,
				)

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[ajbeattie]

Very nice 💯. One small request if you're amenable to it!

[ajbeattie]

🚀