From 7186d3ba8ba3df736f6a41e3ab773db3a3698f3f Mon Sep 17 00:00:00 2001
From: Krzysztof Jastrzebski <kjastrzebski@google.com>
Date: Mon, 28 Jan 2019 14:07:20 +0100
Subject: [PATCH] Delete pods assigned to not existing nodes.

---
 pkg/controller/daemon/daemon_controller.go    | 21 +++++++++++++++++++
 .../daemon/daemon_controller_test.go          | 19 +++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/pkg/controller/daemon/daemon_controller.go b/pkg/controller/daemon/daemon_controller.go
index bf7019f117c..4a2dd7a1e95 100644
--- a/pkg/controller/daemon/daemon_controller.go
+++ b/pkg/controller/daemon/daemon_controller.go
@@ -964,6 +964,9 @@ func (dsc *DaemonSetsController) manage(ds *apps.DaemonSet, hash string) error {
 		failedPodsObserved += failedPodsObservedOnNode
 	}
 
+	// Remove pods assigned to not existing nodes.
+	podsToDelete = append(podsToDelete, getPodsWithoutNode(nodeList, nodeToDaemonPods)...)
+
 	// Label new pods using the hash label value of the current history when creating them
 	if err = dsc.syncNodes(ds, podsToDelete, nodesNeedingDaemonPods, hash); err != nil {
 		return err
@@ -1524,3 +1527,21 @@ func (o podByCreationTimestampAndPhase) Less(i, j int) bool {
 func failedPodsBackoffKey(ds *apps.DaemonSet, nodeName string) string {
 	return fmt.Sprintf("%s/%d/%s", ds.UID, ds.Status.ObservedGeneration, nodeName)
 }
+
+// getPodsWithoutNode returns list of pods assigned to not existing nodes.
+func getPodsWithoutNode(
+	runningNodesList []*v1.Node, nodeToDaemonPods map[string][]*v1.Pod) []string {
+	var results []string
+	isNodeRunning := make(map[string]bool)
+	for _, node := range runningNodesList {
+		isNodeRunning[node.Name] = true
+	}
+	for n, pods := range nodeToDaemonPods {
+		if !isNodeRunning[n] {
+			for _, pod := range pods {
+				results = append(results, pod.Name)
+			}
+		}
+	}
+	return results
+}
diff --git a/pkg/controller/daemon/daemon_controller_test.go b/pkg/controller/daemon/daemon_controller_test.go
index 59fe7c026b3..a2b43dfd197 100644
--- a/pkg/controller/daemon/daemon_controller_test.go
+++ b/pkg/controller/daemon/daemon_controller_test.go
@@ -2447,6 +2447,25 @@ func TestDeleteNoDaemonPod(t *testing.T) {
 	}
 }
 
+func TestDeletePodForNotExistingNode(t *testing.T) {
+	for _, f := range []bool{true, false} {
+		defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.ScheduleDaemonSetPods, f)()
+		for _, strategy := range updateStrategies() {
+			ds := newDaemonSet("foo")
+			ds.Spec.UpdateStrategy = *strategy
+			manager, podControl, _, err := newTestController(ds)
+			if err != nil {
+				t.Fatalf("error creating DaemonSets controller: %v", err)
+			}
+			manager.dsStore.Add(ds)
+			addNodes(manager.nodeStore, 0, 1, nil)
+			addPods(manager.podStore, "node-0", simpleDaemonSetLabel, ds, 1)
+			addPods(manager.podStore, "node-1", simpleDaemonSetLabel, ds, 1)
+			syncAndValidateDaemonSets(t, manager, ds, podControl, 0, 1, 0)
+		}
+	}
+}
+
 func TestGetNodesToDaemonPods(t *testing.T) {
 	for _, f := range []bool{true, false} {
 		defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.ScheduleDaemonSetPods, f)()