disable GC and backup deletion if Kubernetes is less than v1.7.5

Signed-off-by: Steve Kriss <[email protected]>

pkg/cmd/cli/backup/delete.go

@@ -20,11 +20,14 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 
 	api "github.com/heptio/ark/pkg/apis/ark/v1"
 	"github.com/heptio/ark/pkg/client"
 	"github.com/heptio/ark/pkg/cmd"
+	"github.com/heptio/ark/pkg/controller"
+	kubeutil "github.com/heptio/ark/pkg/util/kube"
 )
 
 func NewDeleteCommand(f client.Factory, use string) *cobra.Command {
@@ -37,6 +40,16 @@ func NewDeleteCommand(f client.Factory, use string) *cobra.Command {
 				os.Exit(1)
 			}
 
+			kubeClient, err := f.KubeClient()
+			cmd.CheckError(err)
+
+			serverVersion, err := kubeutil.ServerVersion(kubeClient.Discovery())
+			cmd.CheckError(err)
+
+			if !serverVersion.AtLeast(controller.MinVersionForDelete) {
+				cmd.CheckError(errors.Errorf("this command requires the Kubernetes server version to be at least %s", controller.MinVersionForDelete))
+			}
+
 			arkClient, err := f.Client()
 			cmd.CheckError(err)
 

pkg/cmd/server/server.go

@@ -55,6 +55,7 @@ import (
 	"github.com/heptio/ark/pkg/plugin"
 	"github.com/heptio/ark/pkg/restore"
 	"github.com/heptio/ark/pkg/util/kube"
+	kubeutil "github.com/heptio/ark/pkg/util/kube"
 	"github.com/heptio/ark/pkg/util/logging"
 )
 
@@ -470,22 +471,31 @@ func (s *server) runControllers(config *api.Config) error {
 			wg.Done()
 		}()
 
-		gcController := controller.NewGCController(
-			s.backupService,
-			s.snapshotService,
-			config.BackupStorageProvider.Bucket,
-			config.GCSyncPeriod.Duration,
-			s.sharedInformerFactory.Ark().V1().Backups(),
-			s.arkClient.ArkV1(),
-			s.sharedInformerFactory.Ark().V1().Restores(),
-			s.arkClient.ArkV1(),
-			s.logger,
-		)
-		wg.Add(1)
-		go func() {
-			gcController.Run(ctx, 1)
-			wg.Done()
-		}()
+		serverVersion, err := kubeutil.ServerVersion(s.kubeClient.Discovery())
+		if err != nil {
+			return err
+		}
+
+		if !serverVersion.AtLeast(controller.MinVersionForDelete) {
+			s.logger.Errorf("Garbage-collection is disabled because it requires the Kubernetes server version to be at least %s", controller.MinVersionForDelete)
+		} else {
+			gcController := controller.NewGCController(
+				s.backupService,
+				s.snapshotService,
+				config.BackupStorageProvider.Bucket,
+				config.GCSyncPeriod.Duration,
+				s.sharedInformerFactory.Ark().V1().Backups(),
+				s.arkClient.ArkV1(),
+				s.sharedInformerFactory.Ark().V1().Restores(),
+				s.arkClient.ArkV1(),
+				s.logger,
+			)
+			wg.Add(1)
+			go func() {
+				gcController.Run(ctx, 1)
+				wg.Done()
+			}()
+		}
 	}
 
 	restorer, err := newRestorer(

pkg/controller/gc_controller.go

@@ -31,6 +31,7 @@ import (
 	kerrors "k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/tools/cache"
+	"k8s.io/kubernetes/pkg/util/version"
 
 	api "github.com/heptio/ark/pkg/apis/ark/v1"
 	"github.com/heptio/ark/pkg/cloudprovider"
@@ -42,6 +43,13 @@ import (
 
 const gcFinalizer = "gc.ark.heptio.com"
 
+// MinVersionForDelete is the minimum Kubernetes server version that Ark
+// requires in order to be able to properly delete backups (including
+// the associated snapshots and object storage files). This is because
+// Ark uses finalizers on the backup CRD to implement garbage-collection
+// and deletion.
+var MinVersionForDelete = version.MustParseSemantic("1.7.5")
+
 // gcController removes expired backup content from object storage.
 type gcController struct {
 	backupService       cloudprovider.BackupService

pkg/util/kube/utils.go

@@ -24,7 +24,9 @@ import (
 	"k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/discovery"
 	corev1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/kubernetes/pkg/util/version"
 )
 
 // NamespaceAndName returns a string in the format <namespace>/<name>
@@ -48,3 +50,17 @@ func EnsureNamespaceExists(namespace *v1.Namespace, client corev1.NamespaceInter
 		return false, errors.Wrapf(err, "error creating namespace %s", namespace.Name)
 	}
 }
+
+func ServerVersion(client discovery.DiscoveryInterface) (*version.Version, error) {
+	versionInfo, err := client.ServerVersion()
+	if err != nil {
+		return nil, errors.Wrap(err, "error getting server version")
+	}
+
+	semVer, err := version.ParseSemantic(versionInfo.String())
+	if err != nil {
+		return nil, errors.Wrap(err, "error parsing server version")
+	}
+
+	return semVer, err
+}