Add option to ignore pods with PVCs from eviction

pkg/api/types.go

@@ -35,6 +35,9 @@ type DeschedulerPolicy struct {
 	// EvictLocalStoragePods allows pods using local storage to be evicted.
 	EvictLocalStoragePods *bool
 
+	// IgnorePVCPods prevents pods with PVCs from being evicted.
+	IgnorePVCPods *bool
+
 	// MaxNoOfPodsToEvictPerNode restricts maximum of pods to be evicted per node.
 	MaxNoOfPodsToEvictPerNode *int
 }

pkg/api/v1alpha1/types.go

@@ -35,6 +35,9 @@ type DeschedulerPolicy struct {
 	// EvictLocalStoragePods allows pods using local storage to be evicted.
 	EvictLocalStoragePods *bool `json:"evictLocalStoragePods,omitempty"`
 
+	// IgnorePVCPods prevents pods with PVCs from being evicted.
+	IgnorePVCPods *bool `json:"ignorePvcPods,omitempty"`
+
 	// MaxNoOfPodsToEvictPerNode restricts maximum of pods to be evicted per node.
 	MaxNoOfPodsToEvictPerNode *int `json:"maxNoOfPodsToEvictPerNode,omitempty"`
 }

pkg/api/v1alpha1/zz_generated.conversion.go

@@ -122,6 +122,7 @@ func autoConvert_v1alpha1_DeschedulerPolicy_To_api_DeschedulerPolicy(in *Desched
 	out.Strategies = *(*api.StrategyList)(unsafe.Pointer(&in.Strategies))
 	out.NodeSelector = (*string)(unsafe.Pointer(in.NodeSelector))
 	out.EvictLocalStoragePods = (*bool)(unsafe.Pointer(in.EvictLocalStoragePods))
+	out.IgnorePVCPods = (*bool)(unsafe.Pointer(in.IgnorePVCPods))
 	out.MaxNoOfPodsToEvictPerNode = (*int)(unsafe.Pointer(in.MaxNoOfPodsToEvictPerNode))
 	return nil
 }
@@ -135,6 +136,7 @@ func autoConvert_api_DeschedulerPolicy_To_v1alpha1_DeschedulerPolicy(in *api.Des
 	out.Strategies = *(*StrategyList)(unsafe.Pointer(&in.Strategies))
 	out.NodeSelector = (*string)(unsafe.Pointer(in.NodeSelector))
 	out.EvictLocalStoragePods = (*bool)(unsafe.Pointer(in.EvictLocalStoragePods))
+	out.IgnorePVCPods = (*bool)(unsafe.Pointer(in.IgnorePVCPods))
 	out.MaxNoOfPodsToEvictPerNode = (*int)(unsafe.Pointer(in.MaxNoOfPodsToEvictPerNode))
 	return nil
 }

pkg/api/v1alpha1/zz_generated.deepcopy.go

@@ -45,6 +45,11 @@ func (in *DeschedulerPolicy) DeepCopyInto(out *DeschedulerPolicy) {
 		*out = new(bool)
 		**out = **in
 	}
+	if in.IgnorePVCPods != nil {
+		in, out := &in.IgnorePVCPods, &out.IgnorePVCPods
+		*out = new(bool)
+		**out = **in
+	}
 	if in.MaxNoOfPodsToEvictPerNode != nil {
 		in, out := &in.MaxNoOfPodsToEvictPerNode, &out.MaxNoOfPodsToEvictPerNode
 		*out = new(int)

pkg/api/zz_generated.deepcopy.go

@@ -45,6 +45,11 @@ func (in *DeschedulerPolicy) DeepCopyInto(out *DeschedulerPolicy) {
 		*out = new(bool)
 		**out = **in
 	}
+	if in.IgnorePVCPods != nil {
+		in, out := &in.IgnorePVCPods, &out.IgnorePVCPods
+		*out = new(bool)
+		**out = **in
+	}
 	if in.MaxNoOfPodsToEvictPerNode != nil {
 		in, out := &in.MaxNoOfPodsToEvictPerNode, &out.MaxNoOfPodsToEvictPerNode
 		*out = new(int)

pkg/apis/componentconfig/types.go

@@ -50,6 +50,9 @@ type DeschedulerConfiguration struct {
 	// EvictLocalStoragePods allows pods using local storage to be evicted.
 	EvictLocalStoragePods bool
 
+	// IgnorePVCPods sets whether PVC pods should be allowed to be evicted
+	IgnorePVCPods bool
+
 	// Logging specifies the options of logging.
 	// Refer [Logs Options](https://github.com/kubernetes/component-base/blob/master/logs/options.go) for more information.
 	Logging componentbaseconfig.LoggingConfiguration

pkg/apis/componentconfig/v1alpha1/types.go

@@ -50,6 +50,9 @@ type DeschedulerConfiguration struct {
 	// EvictLocalStoragePods allows pods using local storage to be evicted.
 	EvictLocalStoragePods bool `json:"evictLocalStoragePods,omitempty"`
 
+	// IgnorePVCPods sets whether PVC pods should be allowed to be evicted
+	IgnorePVCPods bool `json:"ignorePvcPods,omitempty"`
+
 	// Logging specifies the options of logging.
 	// Refer [Logs Options](https://github.com/kubernetes/component-base/blob/master/logs/options.go) for more information.
 	Logging componentbaseconfig.LoggingConfiguration `json:"logging,omitempty"`

pkg/apis/componentconfig/v1alpha1/zz_generated.conversion.go

@@ -56,6 +56,7 @@ func autoConvert_v1alpha1_DeschedulerConfiguration_To_componentconfig_Deschedule
 	out.NodeSelector = in.NodeSelector
 	out.MaxNoOfPodsToEvictPerNode = in.MaxNoOfPodsToEvictPerNode
 	out.EvictLocalStoragePods = in.EvictLocalStoragePods
+	out.IgnorePVCPods = in.IgnorePVCPods
 	out.Logging = in.Logging
 	return nil
 }
@@ -73,6 +74,7 @@ func autoConvert_componentconfig_DeschedulerConfiguration_To_v1alpha1_Deschedule
 	out.NodeSelector = in.NodeSelector
 	out.MaxNoOfPodsToEvictPerNode = in.MaxNoOfPodsToEvictPerNode
 	out.EvictLocalStoragePods = in.EvictLocalStoragePods
+	out.IgnorePVCPods = in.IgnorePVCPods
 	out.Logging = in.Logging
 	return nil
 }

pkg/descheduler/descheduler.go

@@ -90,6 +90,11 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 		evictLocalStoragePods = *deschedulerPolicy.EvictLocalStoragePods
 	}
 
+	ignorePvcPods := false
+	if deschedulerPolicy.IgnorePVCPods != nil {
+		ignorePvcPods = *deschedulerPolicy.IgnorePVCPods
+	}
+
 	maxNoOfPodsToEvictPerNode := rs.MaxNoOfPodsToEvictPerNode
 	if deschedulerPolicy.MaxNoOfPodsToEvictPerNode != nil {
 		maxNoOfPodsToEvictPerNode = *deschedulerPolicy.MaxNoOfPodsToEvictPerNode
@@ -116,6 +121,7 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 			maxNoOfPodsToEvictPerNode,
 			nodes,
 			evictLocalStoragePods,
+			ignorePvcPods,
 		)
 
 		for name, f := range strategyFuncs {

pkg/descheduler/evictions/evictions.go

@@ -51,6 +51,7 @@ type PodEvictor struct {
 	maxPodsToEvictPerNode int
 	nodepodCount          nodePodEvictedCount
 	evictLocalStoragePods bool
+	ignorePvcPods         bool
 }
 
 func NewPodEvictor(
@@ -60,6 +61,7 @@ func NewPodEvictor(
 	maxPodsToEvictPerNode int,
 	nodes []*v1.Node,
 	evictLocalStoragePods bool,
+	ignorePvcPods bool,
 ) *PodEvictor {
 	var nodePodCount = make(nodePodEvictedCount)
 	for _, node := range nodes {
@@ -74,6 +76,7 @@ func NewPodEvictor(
 		maxPodsToEvictPerNode: maxPodsToEvictPerNode,
 		nodepodCount:          nodePodCount,
 		evictLocalStoragePods: evictLocalStoragePods,
+		ignorePvcPods:         ignorePvcPods,
 	}
 }
 
@@ -189,6 +192,14 @@ func (pe *PodEvictor) Evictable(opts ...func(opts *Options)) *evictable {
 			return nil
 		})
 	}
+	if pe.ignorePvcPods {
+		ev.constraints = append(ev.constraints, func(pod *v1.Pod) error {
+			if IsPodWithPVC(pod) {
+				return fmt.Errorf("pod has a PVC and descheduler is configured to ignore PVC pods")
+			}
+			return nil
+		})
+	}
 	if options.priority != nil {
 		ev.constraints = append(ev.constraints, func(pod *v1.Pod) error {
 			if IsPodEvictableBasedOnPriority(pod, *options.priority) {
@@ -267,6 +278,15 @@ func IsPodWithLocalStorage(pod *v1.Pod) bool {
 	return false
 }
 
+func IsPodWithPVC(pod *v1.Pod) bool {
+	for _, volume := range pod.Spec.Volumes {
+		if volume.PersistentVolumeClaim != nil {
+			return true
+		}
+	}
+	return false
+}
+
 // IsPodEvictableBasedOnPriority checks if the given pod is evictable based on priority resolved from pod Spec.
 func IsPodEvictableBasedOnPriority(pod *v1.Pod, priority int32) bool {
 	return pod.Spec.Priority == nil || *pod.Spec.Priority < priority

pkg/descheduler/strategies/duplicates_test.go

@@ -210,6 +210,7 @@ func TestFindDuplicatePods(t *testing.T) {
 				testCase.maxPodsToEvictPerNode,
 				[]*v1.Node{node1, node2},
 				false,
+				false,
 			)
 
 			RemoveDuplicatePods(ctx, fakeClient, testCase.strategy, []*v1.Node{node1, node2}, podEvictor)
@@ -405,6 +406,7 @@ func TestRemoveDuplicatesUniformly(t *testing.T) {
 				testCase.maxPodsToEvictPerNode,
 				testCase.nodes,
 				false,
+				false,
 			)
 
 			RemoveDuplicatePods(ctx, fakeClient, testCase.strategy, testCase.nodes, podEvictor)

pkg/descheduler/strategies/lownodeutilization_test.go

@@ -444,6 +444,7 @@ func TestLowNodeUtilization(t *testing.T) {
 				test.maxPodsToEvictPerNode,
 				nodes,
 				false,
+				false,
 			)
 
 			strategy := api.DeschedulerStrategy{
@@ -764,6 +765,7 @@ func TestWithTaints(t *testing.T) {
 				item.evictionsExpected,
 				item.nodes,
 				false,
+				false,
 			)
 
 			LowNodeUtilization(ctx, fakeClient, strategy, item.nodes, podEvictor)

pkg/descheduler/strategies/node_affinity_test.go

@@ -158,6 +158,7 @@ func TestRemovePodsViolatingNodeAffinity(t *testing.T) {
 			tc.maxPodsToEvictPerNode,
 			tc.nodes,
 			false,
+			false,
 		)
 
 		RemovePodsViolatingNodeAffinity(ctx, fakeClient, tc.strategy, tc.nodes, podEvictor)

pkg/descheduler/strategies/node_taint_test.go

@@ -171,6 +171,7 @@ func TestDeletePodsViolatingNodeTaints(t *testing.T) {
 			tc.maxPodsToEvictPerNode,
 			tc.nodes,
 			tc.evictLocalStoragePods,
+			false,
 		)
 
 		RemovePodsViolatingNodeTaints(ctx, fakeClient, api.DeschedulerStrategy{}, tc.nodes, podEvictor)

pkg/descheduler/strategies/pod_antiaffinity_test.go

@@ -120,6 +120,7 @@ func TestPodAntiAffinity(t *testing.T) {
 			test.maxPodsToEvictPerNode,
 			[]*v1.Node{node},
 			false,
+			false,
 		)
 
 		RemovePodsViolatingInterPodAntiAffinity(ctx, fakeClient, api.DeschedulerStrategy{}, []*v1.Node{node}, podEvictor)

pkg/descheduler/strategies/pod_lifetime_test.go

@@ -98,6 +98,19 @@ func TestPodLifeTime(t *testing.T) {
 	p9.ObjectMeta.OwnerReferences = ownerRef1
 	p10.ObjectMeta.OwnerReferences = ownerRef1
 
+	p11 := test.BuildTestPod("p11", 100, 0, node.Name, func(pod *v1.Pod) {
+		pod.Spec.Volumes = []v1.Volume{
+			{
+				Name: "pvc", VolumeSource: v1.VolumeSource{
+					PersistentVolumeClaim: &v1.PersistentVolumeClaimVolumeSource{ClaimName: "foo"},
+				},
+			},
+		}
+		pod.Namespace = "dev"
+		pod.ObjectMeta.CreationTimestamp = olderPodCreationTime
+		pod.ObjectMeta.OwnerReferences = ownerRef1
+	})
+
 	var maxLifeTime uint = 600
 	testCases := []struct {
 		description             string
@@ -105,6 +118,7 @@ func TestPodLifeTime(t *testing.T) {
 		maxPodsToEvictPerNode   int
 		pods                    []v1.Pod
 		expectedEvictedPodCount int
+		ignorePvcPods           bool
 	}{
 		{
 			description: "Two pods in the `dev` Namespace, 1 is new and 1 very is old. 1 should be evicted.",
@@ -169,6 +183,31 @@ func TestPodLifeTime(t *testing.T) {
 			pods:                    []v1.Pod{*p9, *p10},
 			expectedEvictedPodCount: 1,
 		},
+		{
+			description: "does not evict pvc pods with ignorePvcPods set to true",
+			strategy: api.DeschedulerStrategy{
+				Enabled: true,
+				Params: &api.StrategyParameters{
+					PodLifeTime: &api.PodLifeTime{MaxPodLifeTimeSeconds: &maxLifeTime},
+				},
+			},
+			maxPodsToEvictPerNode:   5,
+			pods:                    []v1.Pod{*p11},
+			expectedEvictedPodCount: 0,
+			ignorePvcPods:           true,
+		},
+		{
+			description: "evicts pvc pods with ignorePvcPods set to false (or unset)",
+			strategy: api.DeschedulerStrategy{
+				Enabled: true,
+				Params: &api.StrategyParameters{
+					PodLifeTime: &api.PodLifeTime{MaxPodLifeTimeSeconds: &maxLifeTime},
+				},
+			},
+			maxPodsToEvictPerNode:   5,
+			pods:                    []v1.Pod{*p11},
+			expectedEvictedPodCount: 1,
+		},
 	}
 
 	for _, tc := range testCases {
@@ -186,6 +225,7 @@ func TestPodLifeTime(t *testing.T) {
 			tc.maxPodsToEvictPerNode,
 			[]*v1.Node{node},
 			false,
+			tc.ignorePvcPods,
 		)
 
 		PodLifeTime(ctx, fakeClient, tc.strategy, []*v1.Node{node}, podEvictor)

pkg/descheduler/strategies/toomanyrestarts_test.go

@@ -172,6 +172,7 @@ func TestRemovePodsHavingTooManyRestarts(t *testing.T) {
 			tc.maxPodsToEvictPerNode,
 			[]*v1.Node{node},
 			false,
+			false,
 		)
 
 		RemovePodsHavingTooManyRestarts(ctx, fakeClient, tc.strategy, []*v1.Node{node}, podEvictor)

pkg/descheduler/strategies/topologyspreadconstraint_test.go

@@ -368,6 +368,7 @@ func TestTopologySpreadConstraint(t *testing.T) {
 				100,
 				tc.nodes,
 				false,
+				false,
 			)
 			RemovePodsViolatingTopologySpreadConstraint(ctx, fakeClient, tc.strategy, tc.nodes, podEvictor)
 			podsEvicted := podEvictor.TotalEvicted()