Merge pull request kubernetes#84415 from langyenan/fix-evict-admit

reject pods when under disk pressure

Author: k8s-ci-robot

pkg/kubelet/eviction/eviction_manager.go

@@ -137,8 +137,10 @@ func (m *managerImpl) Admit(attrs *lifecycle.PodAdmitAttributes) lifecycle.PodAd
 	if kubelettypes.IsCriticalPod(attrs.Pod) {
 		return lifecycle.PodAdmitResult{Admit: true}
 	}
-	// the node has memory pressure, admit if not best-effort
-	if hasNodeCondition(m.nodeConditions, v1.NodeMemoryPressure) {
+
+	// Conditions other than memory pressure reject all pods
+	nodeOnlyHasMemoryPressureCondition := hasNodeCondition(m.nodeConditions, v1.NodeMemoryPressure) && len(m.nodeConditions) == 1
+	if nodeOnlyHasMemoryPressureCondition {
 		notBestEffort := v1.PodQOSBestEffort != v1qos.GetPodQOS(attrs.Pod)
 		if notBestEffort {
 			return lifecycle.PodAdmitResult{Admit: true}

pkg/kubelet/eviction/eviction_manager_test.go

@@ -391,6 +391,52 @@ func TestMemoryPressure(t *testing.T) {
 	}
 }
 
+func makeContainersByQOS(class v1.PodQOSClass) []v1.Container {
+	resource := newResourceList("100m", "1Gi", "")
+	switch class {
+	case v1.PodQOSGuaranteed:
+		return []v1.Container{newContainer("guaranteed-container", resource, resource)}
+	case v1.PodQOSBurstable:
+		return []v1.Container{newContainer("burtable-container", resource, nil)}
+	case v1.PodQOSBestEffort:
+		fallthrough
+	default:
+		return []v1.Container{newContainer("best-effort-container", nil, nil)}
+	}
+}
+
+func TestAdmitUnderNodeConditions(t *testing.T) {
+	manager := &managerImpl{}
+	pods := []*v1.Pod{
+		newPod("guaranteed-pod", scheduling.DefaultPriorityWhenNoDefaultClassExists, makeContainersByQOS(v1.PodQOSGuaranteed), nil),
+		newPod("burstable-pod", scheduling.DefaultPriorityWhenNoDefaultClassExists, makeContainersByQOS(v1.PodQOSBurstable), nil),
+		newPod("best-effort-pod", scheduling.DefaultPriorityWhenNoDefaultClassExists, makeContainersByQOS(v1.PodQOSBestEffort), nil),
+	}
+
+	expected := []bool{true, true, true}
+	for i, pod := range pods {
+		if result := manager.Admit(&lifecycle.PodAdmitAttributes{Pod: pod}); expected[i] != result.Admit {
+			t.Errorf("Admit pod: %v, expected: %v, actual: %v", pod, expected[i], result.Admit)
+		}
+	}
+
+	manager.nodeConditions = []v1.NodeConditionType{v1.NodeMemoryPressure}
+	expected = []bool{true, true, false}
+	for i, pod := range pods {
+		if result := manager.Admit(&lifecycle.PodAdmitAttributes{Pod: pod}); expected[i] != result.Admit {
+			t.Errorf("Admit pod: %v, expected: %v, actual: %v", pod, expected[i], result.Admit)
+		}
+	}
+
+	manager.nodeConditions = []v1.NodeConditionType{v1.NodeMemoryPressure, v1.NodeDiskPressure}
+	expected = []bool{false, false, false}
+	for i, pod := range pods {
+		if result := manager.Admit(&lifecycle.PodAdmitAttributes{Pod: pod}); expected[i] != result.Admit {
+			t.Errorf("Admit pod: %v, expected: %v, actual: %v", pod, expected[i], result.Admit)
+		}
+	}
+}
+
 // parseQuantity parses the specified value (if provided) otherwise returns 0 value
 func parseQuantity(value string) resource.Quantity {
 	if len(value) == 0 {