Finish setting up events for pipeline runs

Add the start events for pipelineruns. Cleanup a bit of dead code
where an event was generated but it's not used anymore.

docs/events.md

@@ -28,14 +28,22 @@ No events are emitted for `Conditions` today (https://github.com/tektoncd/pipeli
   successfully, including post-steps injected by Tekton.
 - `Failed`: this is triggered if the `TaskRun` is completed, but not successfully.
   Causes of failure may be: one the steps failed, the `TaskRun` was cancelled or
-  the `TaskRun` timed out.
+  the `TaskRun` timed out. `Failed` events are also triggered in case the `TaskRun`
+  cannot be executed at all because of validation issues.
 
 ## PipelineRuns
 
 `PipelineRun` events are generated for the following `Reasons`:
 
+- `Started`: this is triggered the first time the `PipelineRun` is picked by the
+  reconciler from its work queue, so it only happens if web-hook validation was
+  successful. Note that this event does not imply that a step started executing,
+  as pipeline, task and bound resource validation must be successful first.
+- `Running`: this is triggered when the `PipelineRun` passes validation and
+  actually starts running.
 - `Succeeded`: this is triggered once all `Tasks` reachable via the DAG are
   executed successfully.
 - `Failed`: this is triggered if the `PipelineRun` is completed, but not
   successfully. Causes of failure may be: one the `Tasks` failed or the
-  `PipelineRun` was cancelled.
+  `PipelineRun` was cancelled or timed out. `Failed` events are also triggered
+  in case the `PipelineRun` cannot be executed at all because of validation issues.

pkg/reconciler/pipelinerun/pipelinerun.go

@@ -144,6 +144,16 @@ func (c *Reconciler) ReconcileKind(ctx context.Context, pr *v1beta1.PipelineRun)
 		}
 		// start goroutine to track pipelinerun timeout only startTime is not set
 		go c.timeoutHandler.WaitPipelineRun(pr, pr.Status.StartTime)
+		// Emit events. During the first reconcile the status of the PipelineRun may change twice
+		// from not Started to Started and then to Running, so we need to sent the event here
+		// and at the end of 'Reconcile' again.
+		// We also want to send the "Started" event as soon as possible for anyone who may be waiting
+		// on the event to perform user facing initialisations, such has reset a CI check status
+		afterCondition := pr.Status.GetCondition(apis.ConditionSucceeded)
+		events.Emit(controller.GetEventRecorder(ctx), nil, afterCondition, pr)
+
+		// We already sent an event for start, so update `before` with the current status
+		before = pr.Status.GetCondition(apis.ConditionSucceeded)
 	}
 
 	if pr.IsDone() {
@@ -243,7 +253,6 @@ func (c *Reconciler) updatePipelineResults(ctx context.Context, pr *v1beta1.Pipe
 
 func (c *Reconciler) reconcile(ctx context.Context, pr *v1beta1.PipelineRun) error {
 	logger := logging.FromContext(ctx)
-	recorder := controller.GetEventRecorder(ctx)
 	// We may be reading a version of the object that was stored at an older version
 	// and may not have had all of the assumed default specified.
 	pr.SetDefaults(contexts.WithUpgradeViaDefaulting(ctx))
@@ -407,12 +416,6 @@ func (c *Reconciler) reconcile(ctx context.Context, pr *v1beta1.PipelineRun) err
 		return controller.NewPermanentError(err)
 	}
 
-	if pipelineState.IsDone() && pr.IsDone() {
-		c.timeoutHandler.Release(pr)
-		recorder.Event(pr, corev1.EventTypeNormal, v1beta1.PipelineRunReasonSuccessful.String(), "PipelineRun completed successfully.")
-		return nil
-	}
-
 	for _, rprt := range pipelineState {
 		err := taskrun.ValidateResolvedTaskResources(rprt.PipelineTask.Params, rprt.ResolvedTaskResources)
 		if err != nil {