Implement pod eviction mechanism.

pkg/rescheduler/evictions/evictions.go

@@ -0,0 +1,54 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package evictions
+
+import (
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/kubernetes/pkg/api/v1"
+	"k8s.io/kubernetes/pkg/apis/policy"
+	"k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
+
+	eutils "github.com/aveshagarwal/rescheduler/pkg/rescheduler/evictions/utils"
+)
+
+func EvictPod(client clientset.Interface, pod *v1.Pod, policyGroupVersion string) (bool, error) {
+	deleteOptions := &metav1.DeleteOptions{}
+	// GracePeriodSeconds ?
+	eviction := &policy.Eviction{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: policyGroupVersion,
+			Kind:       eutils.EvictionKind,
+		},
+		ObjectMeta: metav1.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 %q: %v", pod.Name, err)
+	} else if !apierrors.IsNotFound(err) {
+		return true, fmt.Errorf("error when evicting pod %q: %v", pod.Name, err)
+	} else {
+		return false, err
+	}
+}