v0.13.0

Added

• Reconciliation metrics. Controller::with_observer reports every
  reconciliation pass to a ReconcileObserver, with its Phase (init,
  apply, cleanup, or delete), Outcome (completed, waiting,
  skipped, failed, or abandoned), and duration. Reconcilers can time
  named steps of their work with TraceMetadata::step, and override a
  pass's outcome with TraceMetadata::set_outcome. Passes cancelled mid-way
  (for instance, on losing a leadership lease) are reported as abandoned.
• PrometheusMetrics, behind the new prometheus feature, a
  ReconcileObserver exporting <namespace>_reconciliations_total,
  <namespace>_reconciliation_duration_seconds,
  <namespace>_reconciliation_steps_total, and
  <namespace>_reconciliation_step_duration_seconds, with histogram
  buckets from 10ms to 30s by default.
• Kubernetes events, in the new events module. EventRecorder publishes
  events.k8s.io/v1 events on behalf of one controller, aggregating
  identical repeats into a single event's series, truncating overlong
  notes, and giving up after a timeout (5 seconds by default).
  Controller::with_event_recorder publishes an event on the resource
  whenever reconciling it fails, as determined by the new
  Context::failure_event hook, and enables TraceMetadata::publish_event
  for reconcilers' own events.
• The conditions module, for maintaining a resource's standard
  status.conditions. conditions::set applies a DesiredCondition,
  keeping lastTransitionTime unless the condition's status changes, and
  reports whether anything changed (and so whether the status needs
  writing). conditions::find_observed ignores conditions determined from
  an older generation of the resource.
• Controller::with_name, naming a controller in its metrics and tracing
  span.
• Error is now exported, along with Error::display_chain, so that
  Context::error_action can be overridden outside this crate.

Changed

• The controller field of the reconcile tracing span now defaults to the
  resource kind for contexts without a finalizer, rather than being empty.
• The reconcile tracing span has a new outcome field.