vendor files

vendor/k8s.io/kubernetes/pkg/kubelet/checkpoint/checkpoint.go

@@ -0,0 +1,151 @@
+/*
+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 checkpoint
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/dchest/safefile"
+	"github.com/ghodss/yaml"
+	"github.com/golang/glog"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/kubernetes/pkg/apis/core"
+	"k8s.io/kubernetes/pkg/volume/util"
+)
+
+const (
+	// Delimiter used on checkpoints written to disk
+	delimiter = "_"
+	podPrefix = "Pod"
+)
+
+// Manager is the interface used to manage checkpoints
+// which involves writing resources to disk to recover
+// during restart or failure scenarios.
+// https://github.com/kubernetes/community/pull/1241/files
+type Manager interface {
+	// LoadPods will load checkpointed Pods from disk
+	LoadPods() ([]*v1.Pod, error)
+
+	// WritePod will serialize a Pod to disk
+	WritePod(pod *v1.Pod) error
+
+	// Deletes the checkpoint of the given pod from disk
+	DeletePod(pod *v1.Pod) error
+}
+
+var instance Manager
+var mutex = &sync.Mutex{}
+
+// fileCheckPointManager - is a checkpointer that writes contents to disk
+// The type information of the resource objects are encoded in the name
+type fileCheckPointManager struct {
+	path string
+}
+
+// NewCheckpointManager will create a Manager that points to the following path
+func NewCheckpointManager(path string) Manager {
+	// NOTE: This is a precaution; current implementation should not run
+	// multiple checkpoint managers.
+	mutex.Lock()
+	defer mutex.Unlock()
+	instance = &fileCheckPointManager{path: path}
+	return instance
+}
+
+// GetInstance will return the current Manager, there should be only one.
+func GetInstance() Manager {
+	mutex.Lock()
+	defer mutex.Unlock()
+	return instance
+}
+
+// loadPod will load Pod Checkpoint yaml file.
+func (fcp *fileCheckPointManager) loadPod(file string) (*v1.Pod, error) {
+	return util.LoadPodFromFile(file)
+}
+
+// checkAnnotations will validate the checkpoint annotations exist on the Pod
+func (fcp *fileCheckPointManager) checkAnnotations(pod *v1.Pod) bool {
+	if podAnnotations := pod.GetAnnotations(); podAnnotations != nil {
+		if podAnnotations[core.BootstrapCheckpointAnnotationKey] == "true" {
+			return true
+		}
+	}
+	return false
+}
+
+// getPodPath returns the full qualified path for the pod checkpoint
+func (fcp *fileCheckPointManager) getPodPath(pod *v1.Pod) string {
+	return fmt.Sprintf("%v/Pod%v%v.yaml", fcp.path, delimiter, pod.GetUID())
+}
+
+// LoadPods Loads All Checkpoints from disk
+func (fcp *fileCheckPointManager) LoadPods() ([]*v1.Pod, error) {
+	checkpoints := make([]*v1.Pod, 0)
+	files, err := ioutil.ReadDir(fcp.path)
+	if err != nil {
+		return nil, err
+	}
+	for _, f := range files {
+		// get just the filename
+		_, fname := filepath.Split(f.Name())
+		// Get just the Resource from "Resource_Name"
+		fnfields := strings.Split(fname, delimiter)
+		switch fnfields[0] {
+		case podPrefix:
+			pod, err := fcp.loadPod(fmt.Sprintf("%s/%s", fcp.path, f.Name()))
+			if err != nil {
+				return nil, err
+			}
+			checkpoints = append(checkpoints, pod)
+		default:
+			glog.Warningf("Unsupported checkpoint file detected %v", f)
+		}
+	}
+	return checkpoints, nil
+}
+
+// Writes a checkpoint to a file on disk if annotation is present
+func (fcp *fileCheckPointManager) WritePod(pod *v1.Pod) error {
+	var err error
+	if fcp.checkAnnotations(pod) {
+		if blob, err := yaml.Marshal(pod); err == nil {
+			err = safefile.WriteFile(fcp.getPodPath(pod), blob, 0644)
+		}
+	} else {
+		// This is to handle an edge where a pod update could remove
+		// an annotation and the checkpoint should then be removed.
+		err = fcp.DeletePod(pod)
+	}
+	return err
+}
+
+// Deletes a checkpoint from disk if present
+func (fcp *fileCheckPointManager) DeletePod(pod *v1.Pod) error {
+	podPath := fcp.getPodPath(pod)
+	if err := os.Remove(podPath); !os.IsNotExist(err) {
+		return err
+	}
+	return nil
+}