Add pod condition documentation (#219)

* Fix failed job condition

* Add docs and IsCompleted() fixes

* Bump the mock plugin version

Author: s-vitaliy

docs/user_scenarios.md

@@ -27,3 +27,12 @@ If the stream **is suspended**, you need to create backfill request first and th
 If your stream has failed, you can set `spec.suspended` to `true` to stop the stream.
 To avoid data loss, you may create a backfill request that fills in any gaps occurred during the failure.
 After that, you can set `spec.suspended` to `false` to restart the stream.
+
+## I deleted tha pod and my stream transitioned to failed state, how do I avoid that in the future?
+Arcane streaming is built on top of Kubernetes Jobs. By default, when a pod is deleted manually or due to node eviction,
+all containers in the pod receive a SIGTERM signal and have a grace period to shut down gracefully **with exit code 0**.
+If the containers do not shut down within the grace period, the pod is forcefully terminated. If the pod is terminated
+with a non-zero exit code, Kubernetes counts this pod **as failed** and the job may transition to a failed state.
+It's a responsibility of the user and/or the plugin developer to ensure that the streaming job handles termination signals
+gracefully and exits with code 0 or the exit code that returned by the plugin executable on termination is
+[added to the job's podFailurePolicy](https://kubernetes.io/docs/tasks/job/pod-failure-policy/).

justfile

@@ -27,7 +27,7 @@ mock-stream-plugin:
         --namespace default \
         --set jobTemplateSettings.podFailurePolicySettings.retryOnExitCodes="{120,121}" \
         --set jobTemplateSettings.backoffLimit=1 \
-        --version v1.0.4
+        --version v1.0.5
 
 manifests:
     kubectl apply -f integration_tests/manifests/*.yaml

services/controllers/stream/stream_reconciler.go

@@ -497,7 +497,7 @@ func (s *streamReconciler) getLogger(_ context.Context, request types.Namespaced
 func (s *streamReconciler) updateStreamPhase(ctx context.Context, definition Definition, backfillRequest *v1.BackfillRequest, next Phase, eventFunc controllers.EventFunc) (reconcile.Result, error) {
 	logger := s.getLogger(ctx, definition.NamespacedName())
 	if definition.GetPhase() == next { // coverage-ignore
-		logger.V(0).Info("Stream phase is already set to", "phase", definition.GetPhase())
+		logger.V(0).Info("Stream phase is already set", "phase", definition.GetPhase())
 		return reconcile.Result{}, nil
 	}
 	logger.V(0).Info("updating Stream status", "from", definition.GetPhase(), "to", next)

services/controllers/stream/streaming_job.go

@@ -18,11 +18,21 @@ func (j StreamingJob) CurrentConfiguration() (string, error) { // coverage-ignor
 }
 
 func (j StreamingJob) IsCompleted() bool { // coverage-ignore (trivial)
-	return j.Status.Succeeded > 0
+	for _, condition := range j.Status.Conditions {
+		if condition.Type == v1.JobComplete && condition.Status == "True" {
+			return true
+		}
+	}
+	return false
 }
 
 func (j StreamingJob) IsFailed() bool { // coverage-ignore (trivial)
-	return j.Status.Failed > 0 && j.Status.Failed >= *j.Spec.BackoffLimit
+	for _, condition := range j.Status.Conditions {
+		if condition.Type == v1.JobFailed && condition.Status == "True" {
+			return true
+		}
+	}
+	return false
 }
 
 func (j StreamingJob) ToV1Job() *v1.Job { // coverage-ignore (trivial)