Key Structures

cmd/kuberhealthy

• Config (config.go)
  • Holds all runtime settings loaded from environment variables.
  • Fields cover listen addresses, default scheduling intervals, retention limits, and TLS options.
  • Leader election fields (enablement, lease name/namespace, and timing durations) control Lease-based failover behavior.
  • ReportingURL() derives the absolute /check endpoint advertised to pods.
• Globals (main.go)
  • Struct literal containing the Kubernetes REST config, Kubernetes clientset, controller-runtime client, and the active *kuberhealthy.Kuberhealthy instance.
  • Shared across HTTP handlers so they can perform CRUD operations.

internal/kuberhealthy

• Kuberhealthy (kuberhealthy.go)
  • Encapsulates the scheduling logic for HealthCheck resources.
  • Stores the process context, cancellation function, Kubernetes client, event recorder, reporting URL, leader state, and coordination primitives such as loopMu.
  • Captures controller metrics snapshots (scheduler loop timing, due checks, reaper sweep timing, and deletion counts) for Prometheus export.
  • Exposes methods for starting and stopping the scheduler, beginning specific runs, tracking timeouts, and validating report UUIDs.
• checkRun / activeCheck helpers
  • Maintain in-memory bookkeeping for currently executing checks, ensuring duplicate runs do not overlap and that timeout cleanup can resume after a restart.

pkg/api

• HealthCheck
  • Custom resource definition representing a synthetic check.
  • Spec embeds a CheckPodSpec that includes Kubernetes pod metadata and the exact PodSpec to run, while Status captures runtime results.
  • Status now includes success/failure counters and timestamps for the last OK or failed run, enabling SLO-focused metrics.
• CheckPodSpec and CheckPodMetadata
  • Define the pod template executed for each run, plus optional labels and annotations applied by the controller.
• Helper Functions
  • Functions such as GetCheck, UpdateCheck, and SetCurrentUUID wrap common CRUD tasks and guarantee consistent error handling across packages.

internal/metrics

• Exporter (exporter.go)
  • Reads the stored check status and emits Prometheus gauges, counters, and histograms.
  • Renders metrics from the current in-memory and persisted check state.

These structures communicate primarily through the Kubernetes API server and the shared Globals clients, enabling the controller to orchestrate checks while the HTTP layer provides observability and reporting interfaces.