Observability

• Alerting

  The controller's Kubernetes Events on StageSet transitions, the opt-in PrometheusRule alert catalog with tunable thresholds, and how every alert and Ready reason links to a runbook.

• Logging

  The controller's structured slog output, the --log-level and --log-format flags, reading logs with kubectl and jq, and the chart values that drive them.

• Metrics

  The controller's Prometheus metrics — the stageset_* custom series and controller-runtime signals, scraping with a ServiceMonitor or a plain config, querying with PromQL, and the chart values that drive them.

• Observability

  The four observability pillars for the controller — structured logging, OTLP tracing, Prometheus metrics, and the opt-in alert catalog — plus service level objectives and a ready-made dashboard.

• Tracing

  OpenTelemetry tracing for the controller — the --tracing-endpoint, --tracing-insecure, and --tracing-sample-ratio flags, pointing at an OTLP collector, and the chart values that drive them.