func reconcileSuspendedPods()

in pkg/controller/elasticsearch/driver/suspend.go [33:86]
38 lines of code
12 McCabe index (conditional complexity)

func reconcileSuspendedPods(ctx context.Context, c k8s.Client, es esv1.Elasticsearch, e *expectations.Expectations) error {
	// let's make sure we observe any deletions in the cache to avoid redundant deletion
	pendingPodDeletions, err := e.PendingPodDeletions()
	if err != nil {
		return err
	}
	deletionsSatisfied := len(pendingPodDeletions) == 0

	// suspendedPodNames as indicated by the user on the Elasticsearch resource via an annotation
	// the corresponding configMap has already been reconciled prior to that function
	suspendedPodNames := es.SuspendedPodNames()

	// all known Pods, this is mostly to fine tune the reconciliation to the current state of the Pods, see below
	statefulSets, err := sset.RetrieveActualStatefulSets(c, k8s.ExtractNamespacedName(&es))
	if err != nil {
		return err
	}
	knownPods, err := statefulSets.GetActualPods(c)
	if err != nil {
		return err
	}

	for i, pod := range knownPods {
		pod := pod
		// Pod should be suspended
		if suspendedPodNames.Has(pod.Name) {
			for _, s := range pod.Status.ContainerStatuses {
				// delete the Pod without grace period if the main Elasticsearch container is running
				// and we have seen all expected deletions in the cache
				if deletionsSatisfied && s.Name == esv1.ElasticsearchContainerName && s.State.Running != nil {
					ulog.FromContext(ctx).Info("Deleting suspended pod", "pod_name", pod.Name, "pod_uid", pod.UID,
						"namespace", es.Namespace, "es_name", es.Name)
					// the precondition serves as an additional barrier in addition to the expectation mechanism to
					// not accidentally deleting Pods we do not intent to delete (because our view of the world is out of sync)
					preconditions := client.Preconditions{
						UID:             &pod.UID,
						ResourceVersion: &pod.ResourceVersion,
					}
					if err := c.Delete(ctx, &knownPods[i], preconditions, client.GracePeriodSeconds(0)); err != nil {
						return err
					}
					// record the expected deletion
					e.ExpectDeletion(pod)
				}
			}
		} else if isSuspended(pod) {
			// Pod is suspended. But it should not be. Try to speed up propagation of config map entries so that it can
			// start up again. Without this it can take minutes until the config map file in the Pod's filesystem is
			// updated with the current state.
			annotation.MarkPodAsUpdated(ctx, c, pod)
		}
	}
	return nil
}