Update Mountpoint Pod spec to tolerate all taints (#387)

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pkg/podmounter/mppod/creator.go

@@ -86,7 +86,7 @@ func (c *Creator) Create(pod *corev1.Pod, pvc *corev1.PersistentVolumeClaim) *co
 			}},
 			Affinity: &corev1.Affinity{
 				NodeAffinity: &corev1.NodeAffinity{
-					// This is to making sure Mountpoint Pod gets scheduled into same node as the Pod
+					// This is to making sure Mountpoint Pod gets scheduled into same node as the Workload Pod
 					RequiredDuringSchedulingIgnoredDuringExecution: &corev1.NodeSelector{
 						NodeSelectorTerms: []corev1.NodeSelectorTerm{
 							{
@@ -100,6 +100,16 @@ func (c *Creator) Create(pod *corev1.Pod, pvc *corev1.PersistentVolumeClaim) *co
 					},
 				},
 			},
+			Tolerations: []corev1.Toleration{
+				// Tolerate all taints.
+				// - "NoScheduled" – If the Workload Pod gets scheduled to a node, Mountpoint Pod should also get
+				//   scheduled into the same node to provide the volume.
+				// - "NoExecute" – If the Workload Pod tolerates a "NoExecute" taint, Mountpoint Pod should also
+				//   tolerate it to keep running and provide volume for the Workload Pod.
+				//   If the Workload Pod would get descheduled and then the corresponding Mountpoint Pod
+				//   would also get descheduled naturally due to CSI volume lifecycle.
+				{Operator: corev1.TolerationOpExists},
+			},
 			Volumes: []corev1.Volume{
 				// This emptyDir volume is used for communication between Mountpoint Pod and the CSI Driver Node Pod
 				{

pkg/podmounter/mppod/creator_test.go

@@ -84,6 +84,9 @@ func TestCreatingMountpointPods(t *testing.T) {
 			},
 		},
 	}, mpPod.Spec.Affinity)
+	assert.Equals(t, []corev1.Toleration{
+		{Operator: corev1.TolerationOpExists},
+	}, mpPod.Spec.Tolerations)
 
 	assert.Equals(t, image, mpPod.Spec.Containers[0].Image)
 	assert.Equals(t, imagePullPolicy, mpPod.Spec.Containers[0].ImagePullPolicy)

tests/controller/controller_test.go

@@ -702,6 +702,11 @@ func verifyMountpointPodFor(pod *testPod, vol *testVolume, mountpointPod *testPo
 			}},
 		},
 	}))
+	Expect(mountpointPod.Spec.Tolerations).To(Equal([]corev1.Toleration{
+		{
+			Operator: corev1.TolerationOpExists,
+		},
+	}))
 
 	Expect(mountpointPod.Spec.Containers[0].Image).To(Equal(mountpointImage))
 	Expect(mountpointPod.Spec.Containers[0].ImagePullPolicy).To(Equal(mountpointImagePullPolicy))