backup-operator: Support periodically backup (#1841)

CHANGELOG.md

@@ -4,6 +4,13 @@
 
 ### Changed
 
+- EtcdBackup: Support periodically backup. This change added 3 new fileds in EtcdBackup schema, 2 variables is in spec, 1 varialbe is in status.
+  - in spec.backupPolicy
+    - maxBackup which indicate maximum number of backup to keep
+    - backupIntervalInSecond which indicate how often do backup operation.
+  - in status
+    - LastSuccessDate which indicate the last time to succeed in taking backup
+
 ### Removed
 
 ### Fixed

example/etcd-backup-operator/periodic_backup_cr.yaml

@@ -0,0 +1,16 @@
+apiVersion: "etcd.database.coreos.com/v1beta2"
+kind: "EtcdBackup"
+metadata:
+  name: example-etcd-cluster-periodic-backup
+spec:
+  etcdEndpoints: [<etcd-cluster-endpoints>]
+  storageType: S3
+  backupPolicy:
+    # 0 > enable periodic backup
+    backupIntervalInSecond: 125
+    maxBackups: 4
+  s3:
+    # The format of "path" must be: "<s3-bucket-name>/<path-to-backup-file>"
+    # e.g: "mybucket/etcd.backup"
+    path: <full-s3-path>
+    awsSecret: <aws-secret>

pkg/apis/etcd/v1beta2/backup_types.go

@@ -14,7 +14,9 @@
 
 package v1beta2
 
-import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
 
 const (
 	// AWS S3 related consts
@@ -94,6 +96,12 @@ type BackupSource struct {
 type BackupPolicy struct {
 	// TimeoutInSecond is the maximal allowed time in second of the entire backup process.
 	TimeoutInSecond int64 `json:"timeoutInSecond,omitempty"`
+	// BackupIntervalInSecond is to specify how often operator take snapshot
+	// 0 is magic number to indicate one-shot backup
+	BackupIntervalInSecond int64 `json:"backupIntervalInSecond,omitempty"`
+	// MaxBackups is to specify how many backups we want to keep
+	// 0 is magic number to indicate un-limited backups
+	MaxBackups int `json:"maxBackups,omitempty"`
 }
 
 // BackupStatus represents the status of the EtcdBackup Custom Resource.
@@ -106,6 +114,8 @@ type BackupStatus struct {
 	EtcdVersion string `json:"etcdVersion,omitempty"`
 	// EtcdRevision is the revision of etcd's KV store where the backup is performed on.
 	EtcdRevision int64 `json:"etcdRevision,omitempty"`
+	// LastSuccessDate indicate the time to get snapshot last time
+	LastSuccessDate metav1.Time `json:"lastSuccessDate,omitempty"`
 }
 
 // S3BackupSource provides the spec how to store backups on S3.

pkg/backup/backup_manager.go

@@ -18,12 +18,15 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
+	"sort"
+	"time"
 
 	"github.com/coreos/etcd-operator/pkg/backup/writer"
 	"github.com/coreos/etcd-operator/pkg/util/constants"
 
 	"github.com/coreos/etcd/clientv3"
 	"github.com/sirupsen/logrus"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 )
 
@@ -51,29 +54,52 @@ func NewBackupManagerFromWriter(kubecli kubernetes.Interface, bw writer.Writer,
 
 // SaveSnap uses backup writer to save etcd snapshot to a specified S3 path
 // and returns backup etcd server's kv store revision and its version.
-func (bm *BackupManager) SaveSnap(ctx context.Context, s3Path string) (int64, string, error) {
+func (bm *BackupManager) SaveSnap(ctx context.Context, s3Path string, isPeriodic bool) (int64, string, *metav1.Time, error) {
+	now := time.Now().UTC()
 	etcdcli, rev, err := bm.etcdClientWithMaxRevision(ctx)
 	if err != nil {
-		return 0, "", fmt.Errorf("create etcd client failed: %v", err)
+		return 0, "", nil, fmt.Errorf("create etcd client failed: %v", err)
 	}
 	defer etcdcli.Close()
 
 	resp, err := etcdcli.Status(ctx, etcdcli.Endpoints()[0])
 	if err != nil {
-		return 0, "", fmt.Errorf("failed to retrieve etcd version from the status call: %v", err)
+		return 0, "", nil, fmt.Errorf("failed to retrieve etcd version from the status call: %v", err)
 	}
 
 	rc, err := etcdcli.Snapshot(ctx)
 	if err != nil {
-		return 0, "", fmt.Errorf("failed to receive snapshot (%v)", err)
+		return 0, "", nil, fmt.Errorf("failed to receive snapshot (%v)", err)
 	}
 	defer rc.Close()
-
+	if isPeriodic {
+		s3Path = fmt.Sprintf(s3Path+"_v%d_%s", rev, now.Format("2006-01-02-15:04:05"))
+	}
 	_, err = bm.bw.Write(ctx, s3Path, rc)
 	if err != nil {
-		return 0, "", fmt.Errorf("failed to write snapshot (%v)", err)
+		return 0, "", nil, fmt.Errorf("failed to write snapshot (%v)", err)
+	}
+	return rev, resp.Version, &metav1.Time{Time: now}, nil
+}
+
+// EnsureMaxBackup to ensure the number of snapshot is under maxcount
+// if the number of snapshot exceeded than maxcount, delete oldest snapshot
+func (bm *BackupManager) EnsureMaxBackup(ctx context.Context, basePath string, maxCount int) error {
+	savedSnapShots, err := bm.bw.List(ctx, basePath)
+	if err != nil {
+		return fmt.Errorf("failed to get exisiting snapshots: %v", err)
+	}
+	sort.Sort(sort.Reverse(sort.StringSlice(savedSnapShots)))
+	for i, snapshotPath := range savedSnapShots {
+		if i < maxCount {
+			continue
+		}
+		err := bm.bw.Delete(ctx, snapshotPath)
+		if err != nil {
+			return fmt.Errorf("failed to delete snapshot: %v", err)
+		}
 	}
-	return rev, resp.Version, nil
+	return nil
 }
 
 // etcdClientWithMaxRevision gets the etcd endpoint with the maximum kv store revision

pkg/backup/writer/abs_writer.go

@@ -100,3 +100,50 @@ func (absw *absWriter) Write(ctx context.Context, path string, r io.Reader) (int
 
 	return blob.Properties.ContentLength, nil
 }
+
+func (absw *absWriter) List(ctx context.Context, basePath string) ([]string, error) {
+	// TODO: support context.
+	container, _, err := util.ParseBucketAndKey(basePath)
+	if err != nil {
+		return nil, err
+	}
+
+	containerRef := absw.abs.GetContainerReference(container)
+	containerExists, err := containerRef.Exists()
+	if err != nil {
+		return nil, err
+	}
+	if !containerExists {
+		return nil, fmt.Errorf("container %v does not exist", container)
+	}
+
+	blobs, err := containerRef.ListBlobs(
+		storage.ListBlobsParameters{Prefix: basePath})
+	if err != nil {
+		return nil, err
+	}
+	blobKeys := []string{}
+	for _, blob := range blobs.Blobs {
+		blobKeys = append(blobKeys, container+"/"+blob.Name)
+	}
+	return blobKeys, nil
+}
+
+func (absw *absWriter) Delete(ctx context.Context, path string) error {
+	// TODO: support context.
+	container, key, err := util.ParseBucketAndKey(path)
+	if err != nil {
+		return err
+	}
+	containerRef := absw.abs.GetContainerReference(container)
+	containerExists, err := containerRef.Exists()
+	if err != nil {
+		return err
+	}
+	if !containerExists {
+		return fmt.Errorf("container %v does not exist", container)
+	}
+
+	blob := containerRef.GetBlobReference(key)
+	return blob.Delete(&storage.DeleteBlobOptions{})
+}

pkg/backup/writer/gcs_writer.go

@@ -23,6 +23,7 @@ import (
 
 	"cloud.google.com/go/storage"
 	"github.com/sirupsen/logrus"
+	"google.golang.org/api/iterator"
 )
 
 var _ Writer = &gcsWriter{}
@@ -58,3 +59,37 @@ func (gcsw *gcsWriter) Write(ctx context.Context, path string, r io.Reader) (int
 	}
 	return n, err
 }
+
+func (gcsw *gcsWriter) List(ctx context.Context, basePath string) ([]string, error) {
+	bucket, key, err := util.ParseBucketAndKey(basePath)
+	if err != nil {
+		return nil, err
+	}
+	objects := gcsw.gcs.Bucket(bucket).Objects(ctx, &storage.Query{Prefix: key})
+	if objects == nil {
+		return nil, fmt.Errorf("failed to get objects having %s prefix", key)
+	}
+
+	objectKeys := []string{}
+
+	for {
+		objAttrs, err := objects.Next()
+		if err == iterator.Done {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		objectKeys = append(objectKeys, bucket+"/"+objAttrs.Name)
+	}
+	return objectKeys, nil
+}
+
+func (gcsw *gcsWriter) Delete(ctx context.Context, path string) error {
+	bucket, key, err := util.ParseBucketAndKey(path)
+	if err != nil {
+		return err
+	}
+
+	return gcsw.gcs.Bucket(bucket).Object(key).Delete(ctx)
+}

pkg/backup/writer/s3_writer.go

@@ -67,3 +67,39 @@ func (s3w *s3Writer) Write(ctx context.Context, path string, r io.Reader) (int64
 	}
 	return *resp.ContentLength, nil
 }
+
+// List return the file paths which match the given s3 path
+func (s3w *s3Writer) List(ctx context.Context, basePath string) ([]string, error) {
+	bk, key, err := util.ParseBucketAndKey(basePath)
+	if err != nil {
+		return nil, err
+	}
+
+	objects, err := s3w.s3.ListObjectsWithContext(ctx,
+		&s3.ListObjectsInput{
+			Bucket: aws.String(bk),
+			Prefix: aws.String(key),
+		})
+	if err != nil {
+		return nil, err
+	}
+	objectKeys := []string{}
+	for _, object := range objects.Contents {
+		objectKeys = append(objectKeys, bk+"/"+*object.Key)
+	}
+	return objectKeys, nil
+}
+
+func (s3w *s3Writer) Delete(ctx context.Context, path string) error {
+	bk, key, err := util.ParseBucketAndKey(path)
+	if err != nil {
+		return err
+	}
+
+	_, err = s3w.s3.DeleteObjectWithContext(ctx,
+		&s3.DeleteObjectInput{
+			Bucket: aws.String(bk),
+			Key:    aws.String(key),
+		})
+	return err
+}

pkg/backup/writer/writer.go

@@ -23,4 +23,10 @@ import (
 type Writer interface {
 	// Write writes a backup file to the given path and returns size of written file.
 	Write(ctx context.Context, path string, r io.Reader) (int64, error)
+
+	// List backup files
+	List(ctx context.Context, basePath string) ([]string, error)
+
+	// Delete a backup file
+	Delete(ctx context.Context, path string) error
 }

pkg/controller/backup-operator/abs_backup.go

@@ -28,7 +28,8 @@ import (
 )
 
 // handleABS saves etcd cluster's backup to specificed ABS path.
-func handleABS(ctx context.Context, kubecli kubernetes.Interface, s *api.ABSBackupSource, endpoints []string, clientTLSSecret, namespace string) (*api.BackupStatus, error) {
+func handleABS(ctx context.Context, kubecli kubernetes.Interface, s *api.ABSBackupSource, endpoints []string, clientTLSSecret,
+	namespace string, isPeriodic bool, maxBackup int) (*api.BackupStatus, error) {
 	// TODO: controls NewClientFromSecret with ctx. This depends on upstream kubernetes to support API calls with ctx.
 	cli, err := absfactory.NewClientFromSecret(kubecli, namespace, s.ABSSecret)
 	if err != nil {
@@ -39,12 +40,17 @@ func handleABS(ctx context.Context, kubecli kubernetes.Interface, s *api.ABSBack
 	if tlsConfig, err = generateTLSConfig(kubecli, clientTLSSecret, namespace); err != nil {
 		return nil, err
 	}
-
 	bm := backup.NewBackupManagerFromWriter(kubecli, writer.NewABSWriter(cli.ABS), tlsConfig, endpoints, namespace)
 
-	rev, etcdVersion, err := bm.SaveSnap(ctx, s.Path)
+	rev, etcdVersion, now, err := bm.SaveSnap(ctx, s.Path, isPeriodic)
 	if err != nil {
 		return nil, fmt.Errorf("failed to save snapshot (%v)", err)
 	}
-	return &api.BackupStatus{EtcdVersion: etcdVersion, EtcdRevision: rev}, nil
+	if maxBackup > 0 {
+		err := bm.EnsureMaxBackup(ctx, s.Path, maxBackup)
+		if err != nil {
+			return nil, fmt.Errorf("succeeded in saving snapshot but failed to delete old snapshot (%v)", err)
+		}
+	}
+	return &api.BackupStatus{EtcdVersion: etcdVersion, EtcdRevision: rev, LastSuccessDate: *now}, nil
 }