implement Evict

Author: lentil1016

pkg/handler/deschedule.go

@@ -12,7 +12,7 @@ type descheduleHandler struct {
 
 func (dh *descheduleHandler) Handle(event Event) {
 	if timer.IsOutOfTime() {
-		fmt.Println("Deschedule event aborted by timer.")
+		fmt.Println("Deschedule event aborted by timer")
 		return
 	}
 
@@ -21,12 +21,15 @@ func (dh *descheduleHandler) Handle(event Event) {
 	if !ok {
 		return
 	}
-	fmt.Println("descheduleHandler: Deschedule Triggered, start picking Pods.")
-	_, err := predictor.GetEvictablePods(busyNodes)
+	fmt.Println("descheduleHandler: Deschedule Triggered, start picking Pods")
+	evictSize := 2
+	pods, err := predictor.GetEvictPods(busyNodes, evictSize)
 	if err != nil {
 		fmt.Println(err)
 		return
 	}
+	fmt.Println("descheduleHandler: Pods picking done, start to evict")
+	predictor.Evict(pods)
 	isRecovering = true
 	fmt.Println("deschedule event handled")
 }

pkg/predictor/node.go

@@ -19,6 +19,7 @@ type nodeScore struct {
 // Splite node into high spared nodes list and low spared state nodes list
 func GetBusyNodes() ([]*api_v1.Node, bool) {
 	operatableNodes, _ := getOperatableNodes()
+	// TODO: remove Comment marks
 	/*if len(operatableNodes) < 2 {
 		fmt.Println("Deschedule event droped because Operatable node is less than 2")
 		return []*api_v1.Node{}, []*api_v1.Node{}, false

pkg/predictor/pod.go

@@ -3,15 +3,57 @@ package predictor
 import (
 	"fmt"
 
-	"github.com/kubernetes/kubernetes/pkg/kubelet/types"
 	api_v1 "k8s.io/api/core/v1"
+	policy "k8s.io/api/policy/v1beta1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/fields"
 	api "k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/kubelet/types"
 )
 
-func GetEvictablePods(nodes []*api_v1.Node) ([]*api_v1.Pod, error) {
-	pods, err := getPodsOnNode(nodes[0])
+func GetEvictPods(nodes []*api_v1.Node, evictSize int) ([]*api_v1.Pod, error) {
+	var evictPods []*api_v1.Pod
+	for _, node := range nodes {
+		pods, err := getEvictablePods(node)
+		if err != nil {
+			fmt.Printf("Get evictable pods on %v failed, skipping this node. %v\n", node.ObjectMeta.Name, err)
+		}
+		rankedPods := rankEvictablePods(pods)
+		evictPods = append(evictPods, rankedPods...)
+		if len(evictPods) >= evictSize {
+			evictPods = evictPods[:evictSize]
+			break
+		}
+	}
+	return evictPods, nil
+}
+
+func rankEvictablePods(pods []*api_v1.Pod) []*api_v1.Pod {
+	return pods
+}
+
+func getUnfitPods(node *api_v1.Node) []*api_v1.Pod {
+	return []*api_v1.Pod{}
+}
+
+func CheckReplicas(pods []*api_v1.Pod) []*api_v1.Pod {
+	for _, pod := range pods {
+		ownerRefList := ownerRef(pod)
+		if isReplicaSetPod(ownerRefList) {
+
+		}
+	}
+	return []*api_v1.Pod{}
+
+}
+
+func getPodsHaveReplicas(node *api_v1.Node) []*api_v1.Pod {
+	return []*api_v1.Pod{}
+}
+
+func getEvictablePods(node *api_v1.Node) ([]*api_v1.Pod, error) {
+	pods, err := getPodsOnNode(node)
 	if err != nil {
 		return []*api_v1.Pod{}, err
 	}
@@ -46,6 +88,15 @@ func ownerRef(pod *api_v1.Pod) []v1.OwnerReference {
 	return pod.ObjectMeta.GetOwnerReferences()
 }
 
+func isReplicaSetPod(ownerRefList []v1.OwnerReference) bool {
+	for _, ownerRef := range ownerRefList {
+		if ownerRef.Kind == "ReplicaSet" {
+			return true
+		}
+	}
+	return false
+}
+
 func isDaemonsetPod(ownerRefList []v1.OwnerReference) bool {
 	for _, ownerRef := range ownerRefList {
 		if ownerRef.Kind == "DaemonSet" {
@@ -74,19 +125,6 @@ func isCriticalPod(pod *api_v1.Pod) bool {
 	return types.IsCriticalPod(pod)
 }
 
-func getUnfitPods(node *api_v1.Node) []*api_v1.Pod {
-	return []*api_v1.Pod{}
-}
-
-func isWithReplica(node *api_v1.Node) []*api_v1.Pod {
-	return []*api_v1.Pod{}
-
-}
-
-func getPodsHaveReplicas(node *api_v1.Node) []*api_v1.Pod {
-	return []*api_v1.Pod{}
-}
-
 func getPodsOnNode(node *api_v1.Node) ([]*api_v1.Pod, error) {
 	fieldSelector, err := fields.ParseSelector("spec.nodeName=" + node.Name + ",status.phase!=" + string(api.PodFailed))
 	if err != nil {
@@ -105,3 +143,38 @@ func getPodsOnNode(node *api_v1.Node) ([]*api_v1.Pod, error) {
 	}
 	return pods, nil
 }
+
+func Evict(pods []*api_v1.Pod) {
+	for _, pod := range pods {
+		evictPod(pod)
+	}
+}
+
+func evictPod(pod *api_v1.Pod) (bool, error) {
+	if conf.DryRun {
+		return true, nil
+	}
+	deleteOptions := &v1.DeleteOptions{}
+	evictionVersion, _ := supportEviction()
+	eviction := &policy.Eviction{
+		TypeMeta: v1.TypeMeta{
+			APIVersion: evictionVersion,
+			Kind:       "Eviction",
+		},
+		ObjectMeta: v1.ObjectMeta{
+			Name:      pod.Name,
+			Namespace: pod.Namespace,
+		},
+		DeleteOptions: deleteOptions,
+	}
+	err := client.Policy().Evictions(eviction.Namespace).Evict(eviction)
+	if err == nil {
+		return true, nil
+	} else if apierrors.IsTooManyRequests(err) {
+		return false, fmt.Errorf("error when evicting pod (ignoring) %q: %v", pod.Name, err)
+	} else if apierrors.IsNotFound(err) {
+		return true, fmt.Errorf("pod not found when evicting %q: %v", pod.Name, err)
+	} else {
+		return false, err
+	}
+}

pkg/predictor/predictor.go

@@ -54,3 +54,35 @@ func scoreResource(usage, maxUsage, maxSpared, usageScore, sparedScore, normalSc
 	}
 	return usageScore, sparedScore, normalScore
 }
+
+// SupportEviction uses Discovery API to find out if the server support eviction subresource
+// If support, it will return its groupVersion; Otherwise, it will return ""
+func supportEviction() (string, error) {
+	discoveryClient := client.Discovery()
+	groupList, err := discoveryClient.ServerGroups()
+	if err != nil {
+		return "", err
+	}
+	foundPolicyGroup := false
+	var policyGroupVersion string
+	for _, group := range groupList.Groups {
+		if group.Name == "policy" {
+			foundPolicyGroup = true
+			policyGroupVersion = group.PreferredVersion.GroupVersion
+			break
+		}
+	}
+	if !foundPolicyGroup {
+		return "", nil
+	}
+	resourceList, err := discoveryClient.ServerResourcesForGroupVersion("v1")
+	if err != nil {
+		return "", err
+	}
+	for _, resource := range resourceList.APIResources {
+		if resource.Name == "pods/eviction" && resource.Kind == "Eviction" {
+			return policyGroupVersion, nil
+		}
+	}
+	return "", nil
+}