Implement offline backup for multiple replica (#335)

fixes #244

Author: Md. Emruz Hossain

backup.go

@@ -7,9 +7,11 @@ import (
 
 	"github.com/appscode/go/log"
 	"github.com/appscode/kutil/meta"
+	api "github.com/appscode/stash/apis/stash/v1alpha1"
 	cs "github.com/appscode/stash/client/clientset/versioned"
 	"github.com/appscode/stash/pkg/backup"
 	"github.com/appscode/stash/pkg/docker"
+	"github.com/appscode/stash/pkg/scale"
 	"github.com/appscode/stash/pkg/util"
 	"github.com/spf13/cobra"
 	"k8s.io/client-go/kubernetes"
@@ -70,10 +72,33 @@ func NewCmdBackup() *cobra.Command {
 				if err = ctrl.BackupScheduler(); err != nil {
 					log.Fatal(err)
 				}
-			} else {
-				log.Infoln("Running backup once")
-				if err = ctrl.Backup(); err != nil {
-					log.Fatal(err)
+			} else { // for offline backup
+				if opt.Workload.Kind == api.KindDaemonSet || opt.Workload.Kind == api.KindStatefulSet {
+					log.Infoln("Running backup once")
+					if err = ctrl.Backup(); err != nil {
+						log.Fatal(err)
+					}
+				} else {
+					//if replica > 1 we should not take backup
+					replica, err := util.WorkloadReplicas(kubeClient, opt.Namespace, opt.Workload.Kind, opt.Workload.Name)
+					if err != nil {
+						log.Fatal(err)
+					}
+
+					if replica > 1 {
+						log.Infof("Skipping backup. Reason: Backup type offline and replica > 1")
+					} else {
+						log.Infoln("Running backup once")
+						if err = ctrl.Backup(); err != nil {
+							log.Fatal(err)
+						}
+
+						// offline backup done. now scale up replica to original replica number
+						err = scale.ScaleUpWorkload(kubeClient, opt)
+						if err != nil {
+							log.Fatal(err)
+						}
+					}
 				}
 			}
 			log.Infoln("Exiting Stash Backup")

root.go

@@ -55,6 +55,7 @@ func NewRootCmd() *cobra.Command {
 	rootCmd.AddCommand(NewCmdBackup())
 	rootCmd.AddCommand(NewCmdRecover())
 	rootCmd.AddCommand(NewCmdCheck())
+	rootCmd.AddCommand(NewCmdScaleDown())
 
 	return rootCmd
 }

scaledown.go

@@ -0,0 +1,45 @@
+package cmds
+
+import (
+	"github.com/appscode/go/log"
+	"github.com/appscode/kutil/meta"
+	"github.com/appscode/stash/pkg/scale"
+	"github.com/spf13/cobra"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+func NewCmdScaleDown() *cobra.Command {
+	var (
+		masterURL      string
+		kubeconfigPath string
+		opt            = scale.Options{
+			Namespace: meta.Namespace(),
+		}
+	)
+
+	cmd := &cobra.Command{
+		Use:               "scaledown",
+		Short:             "Scale down workload",
+		DisableAutoGenTag: true,
+		Run: func(cmd *cobra.Command, args []string) {
+			config, err := clientcmd.BuildConfigFromFlags(masterURL, kubeconfigPath)
+			if err != nil {
+				log.Fatalf("Could not get Kubernetes config: %s", err)
+			}
+			kubeClient := kubernetes.NewForConfigOrDie(config)
+
+			ctrl := scale.New(kubeClient, opt)
+			err = ctrl.ScaleDownWorkload()
+			if err != nil {
+				log.Fatal(err)
+			}
+
+		},
+	}
+	cmd.Flags().StringVar(&masterURL, "master", masterURL, "The address of the Kubernetes API server (overrides any value in kubeconfig)")
+	cmd.Flags().StringVar(&kubeconfigPath, "kubeconfig", kubeconfigPath, "Path to kubeconfig file with authorization information (the master location is set by the master flag).")
+	cmd.Flags().StringVar(&opt.Selector, "selector", opt.Selector, "Label used to select Restic's workload")
+
+	return cmd
+}

server/options.go

@@ -2,12 +2,10 @@ package server
 
 import (
 	"flag"
-	"fmt"
 	"time"
 
 	stringz "github.com/appscode/go/strings"
 	v "github.com/appscode/go/version"
-	"github.com/appscode/kutil/discovery"
 	cs "github.com/appscode/stash/client/clientset/versioned"
 	hookapi "github.com/appscode/stash/pkg/admission/api"
 	"github.com/appscode/stash/pkg/admission/plugin"
@@ -78,11 +76,5 @@ func (s *ControllerOptions) ApplyTo(cfg *controller.ControllerConfig) error {
 	}
 	cfg.AdmissionHooks = []hookapi.AdmissionHook{&plugin.CRDValidator{}}
 
-	// get kube api server version
-	cfg.KubectlImageTag, err = discovery.GetBaseVersion(cfg.KubeClient.Discovery())
-	if err != nil {
-		return fmt.Errorf("failed to detect server version, reason: %s", err)
-	}
-
 	return nil
 }