Don't delete nodes with pods with local storage

cluster-autoscaler/simulator/cluster.go

@@ -17,6 +17,7 @@ limitations under the License.
 package simulator
 
 import (
+	"flag"
 	"fmt"
 	"math"
 
@@ -29,6 +30,14 @@ import (
 	"github.com/golang/glog"
 )
 
+var (
+	skipNodesWithSystemPods = flag.Bool("skip-nodes-with-system-pods", true,
+		"If true cluster autoscaler will never delete nodes with pods from kube-system (except for DeamonSet "+
+			"or mirror pods)")
+	skipNodesWithLocalStorage = flag.Bool("skip-nodes-with-local-storage", true,
+		"If true cluster autoscaler will never delete nodes with pods with local storage, e.g. EmptyDir or HostPath")
+)
+
 // FindNodesToRemove finds nodes that can be removed.
 func FindNodesToRemove(candidates []*kube_api.Node, allNodes []*kube_api.Node, pods []*kube_api.Pod,
 	client *kube_client.Client, predicateChecker *PredicateChecker, maxCount int,
@@ -56,7 +65,7 @@ candidateloop:
 
 		if fastCheck {
 			if nodeInfo, found := nodeNameToNodeInfo[node.Name]; found {
-				podsToRemove, err = FastGetPodsToMove(nodeInfo, false, true, kube_api.Codecs.UniversalDecoder())
+				podsToRemove, err = FastGetPodsToMove(nodeInfo, false, *skipNodesWithSystemPods, *skipNodesWithLocalStorage, kube_api.Codecs.UniversalDecoder())
 				if err != nil {
 					glog.V(2).Infof("%s: node %s cannot be removed: %v", evaluationType, node.Name, err)
 					continue candidateloop

cluster-autoscaler/simulator/drain.go

@@ -32,7 +32,7 @@ import (
 // along with their pods (no abandoned pods with dangling created-by annotation). Usefull for fast
 // checks.
 func FastGetPodsToMove(nodeInfo *schedulercache.NodeInfo, force bool,
-	failOnKubeSystemAddons bool, decoder runtime.Decoder) ([]*api.Pod, error) {
+	skipNodesWithSystemPods bool, skipNodesWithLocalStorage bool, decoder runtime.Decoder) ([]*api.Pod, error) {
 	pods := make([]*api.Pod, 0)
 	unreplicatedPodNames := []string{}
 	for _, pod := range nodeInfo.Pods() {
@@ -61,10 +61,14 @@ func FastGetPodsToMove(nodeInfo *schedulercache.NodeInfo, force bool,
 			}
 		}
 
-		if !daemonsetPod && pod.Namespace == "kube-system" && failOnKubeSystemAddons {
+		if !daemonsetPod && pod.Namespace == "kube-system" && skipNodesWithSystemPods {
 			return []*api.Pod{}, fmt.Errorf("non-deamons set, non-mirrored, kube-system pod present: %s", pod.Name)
 		}
 
+		if !daemonsetPod && hasLocalStorage(pod) && skipNodesWithLocalStorage {
+			return []*api.Pod{}, fmt.Errorf("pod with local storage present: %s", pod.Name)
+		}
+
 		switch {
 		case daemonsetPod:
 			break
@@ -82,3 +86,16 @@ func FastGetPodsToMove(nodeInfo *schedulercache.NodeInfo, force bool,
 	}
 	return pods, nil
 }
+
+func hasLocalStorage(pod *api.Pod) bool {
+	for _, volume := range pod.Spec.Volumes {
+		if isLocalVolume(&volume) {
+			return true
+		}
+	}
+	return false
+}
+
+func isLocalVolume(volume *api.Volume) bool {
+	return volume.HostPath != nil || volume.EmptyDir != nil
+}

cluster-autoscaler/simulator/drain_test.go

@@ -35,7 +35,7 @@ func TestFastGetPodsToMove(t *testing.T) {
 			Namespace: "ns",
 		},
 	}
-	_, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod1), false, true, kube_api.Codecs.UniversalDecoder())
+	_, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod1), false, true, true, kube_api.Codecs.UniversalDecoder())
 	assert.Error(t, err)
 
 	// Replicated pod
@@ -48,7 +48,7 @@ func TestFastGetPodsToMove(t *testing.T) {
 			},
 		},
 	}
-	r2, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod2), false, true, kube_api.Codecs.UniversalDecoder())
+	r2, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod2), false, true, true, kube_api.Codecs.UniversalDecoder())
 	assert.NoError(t, err)
 	assert.Equal(t, 1, len(r2))
 	assert.Equal(t, pod2, r2[0])
@@ -63,7 +63,7 @@ func TestFastGetPodsToMove(t *testing.T) {
 			},
 		},
 	}
-	r3, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod3), false, true, kube_api.Codecs.UniversalDecoder())
+	r3, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod3), false, true, true, kube_api.Codecs.UniversalDecoder())
 	assert.NoError(t, err)
 	assert.Equal(t, 0, len(r3))
 
@@ -77,7 +77,7 @@ func TestFastGetPodsToMove(t *testing.T) {
 			},
 		},
 	}
-	r4, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod2, pod3, pod4), false, true, kube_api.Codecs.UniversalDecoder())
+	r4, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod2, pod3, pod4), false, true, true, kube_api.Codecs.UniversalDecoder())
 	assert.NoError(t, err)
 	assert.Equal(t, 1, len(r4))
 	assert.Equal(t, pod2, r4[0])
@@ -92,6 +92,53 @@ func TestFastGetPodsToMove(t *testing.T) {
 			},
 		},
 	}
-	_, err = FastGetPodsToMove(schedulercache.NewNodeInfo(pod5), false, true, kube_api.Codecs.UniversalDecoder())
+	_, err = FastGetPodsToMove(schedulercache.NewNodeInfo(pod5), false, true, true, kube_api.Codecs.UniversalDecoder())
 	assert.Error(t, err)
+
+	// Local storage
+	pod6 := &kube_api.Pod{
+		ObjectMeta: kube_api.ObjectMeta{
+			Name:      "pod6",
+			Namespace: "ns",
+			Annotations: map[string]string{
+				"kubernetes.io/created-by": "{\"kind\":\"SerializedReference\",\"apiVersion\":\"v1\",\"reference\":{\"kind\":\"ReplicaSet\"}}",
+			},
+		},
+		Spec: kube_api.PodSpec{
+			Volumes: []kube_api.Volume{
+				{
+					VolumeSource: kube_api.VolumeSource{
+						EmptyDir: &kube_api.EmptyDirVolumeSource{},
+					},
+				},
+			},
+		},
+	}
+	_, err = FastGetPodsToMove(schedulercache.NewNodeInfo(pod6), false, true, true, kube_api.Codecs.UniversalDecoder())
+	assert.Error(t, err)
+
+	// Non-local storage
+	pod7 := &kube_api.Pod{
+		ObjectMeta: kube_api.ObjectMeta{
+			Name:      "pod7",
+			Namespace: "ns",
+			Annotations: map[string]string{
+				"kubernetes.io/created-by": "{\"kind\":\"SerializedReference\",\"apiVersion\":\"v1\",\"reference\":{\"kind\":\"ReplicaSet\"}}",
+			},
+		},
+		Spec: kube_api.PodSpec{
+			Volumes: []kube_api.Volume{
+				{
+					VolumeSource: kube_api.VolumeSource{
+						GitRepo: &kube_api.GitRepoVolumeSource{
+							Repository: "my-repo",
+						},
+					},
+				},
+			},
+		},
+	}
+	r7, err := FastGetPodsToMove(schedulercache.NewNodeInfo(pod7), false, true, true, kube_api.Codecs.UniversalDecoder())
+	assert.NoError(t, err)
+	assert.Equal(t, 1, len(r7))
 }