Revert "Revert "Add support for CSI snapshot beta APIs (kanisterio#633)…

…" (kanisterio#635)" (kanisterio#636)

This reverts commit b24edc9.

pkg/kube/discover.go

@@ -2,6 +2,7 @@ package kube
 
 import (
 	"context"
+	"fmt"
 
 	"k8s.io/client-go/discovery"
 )
@@ -21,3 +22,20 @@ func IsOSAppsGroupAvailable(ctx context.Context, cli discovery.DiscoveryInterfac
 	}
 	return false, nil
 }
+
+// IsGroupVersionAvailable returns true if given group/version is registered.
+func IsGroupVersionAvailable(ctx context.Context, cli discovery.DiscoveryInterface, groupName, version string) (bool, error) {
+	sgs, err := cli.ServerGroups()
+	if err != nil {
+		return false, err
+	}
+
+	for _, g := range sgs.Groups {
+		for _, v := range g.Versions {
+			if fmt.Sprintf("%s/%s", groupName, version) == v.GroupVersion {
+				return true, nil
+			}
+		}
+	}
+	return false, nil
+}

pkg/kube/snapshot/apis/v1alpha1/types.go

@@ -23,6 +23,7 @@ import (
 	storage "k8s.io/api/storage/v1beta1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
 const (
@@ -37,6 +38,15 @@ const (
 	Version   = "v1alpha1"
 )
 
+var (
+	// VolSnapGVR specifies GVR schema for VolumeSnapshots
+	VolSnapGVR = schema.GroupVersionResource{Group: GroupName, Version: Version, Resource: VolumeSnapshotResourcePlural}
+	// VolSnapClassGVR specifies GVR schema for VolumeSnapshotClasses
+	VolSnapClassGVR = schema.GroupVersionResource{Group: GroupName, Version: Version, Resource: VolumeSnapshotClassResourcePlural}
+	// VolSnapContentGVR specifies GVR schema for VolumeSnapshotContents
+	VolSnapContentGVR = schema.GroupVersionResource{Group: GroupName, Version: Version, Resource: VolumeSnapshotContentResourcePlural}
+)
+
 // VolumeSnapshot is a user's request for taking a snapshot. Upon successful creation of the actual
 // snapshot by the volume provider it is bound to the corresponding VolumeSnapshotContent.
 // Only the VolumeSnapshot object is accessible to the user in the namespace.

pkg/kube/snapshot/snapshot.go

@@ -17,10 +17,13 @@ package snapshot
 import (
 	"context"
 
+	"github.com/pkg/errors"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
 
+	"github.com/kanisterio/kanister/pkg/kube"
 	"github.com/kanisterio/kanister/pkg/kube/snapshot/apis/v1alpha1"
+	"github.com/kanisterio/kanister/pkg/kube/snapshot/apis/v1beta1"
 )
 
 type Snapshotter interface {
@@ -83,9 +86,21 @@ type Source struct {
 }
 
 // NewSnapshotter creates and return new Snapshotter object
-func NewSnapshotter(kubeCli kubernetes.Interface, dynCli dynamic.Interface) Snapshotter {
-	return &SnapshotAlpha{
-		kubeCli: kubeCli,
-		dynCli:  dynCli,
+func NewSnapshotter(kubeCli kubernetes.Interface, dynCli dynamic.Interface) (Snapshotter, error) {
+	ctx := context.Background()
+	exists, err := kube.IsGroupVersionAvailable(ctx, kubeCli.Discovery(), v1alpha1.GroupName, v1alpha1.Version)
+	if err != nil {
+		return nil, errors.Errorf("Failed to call discovery APIs: %v", err)
 	}
+	if exists {
+		return NewSnapshotAlpha(kubeCli, dynCli), nil
+	}
+	exists, err = kube.IsGroupVersionAvailable(ctx, kubeCli.Discovery(), v1beta1.GroupName, v1beta1.Version)
+	if err != nil {
+		return nil, errors.Errorf("Failed to call discovery APIs: %v", err)
+	}
+	if exists {
+		return NewSnapshotBeta(kubeCli, dynCli), nil
+	}
+	return nil, errors.New("Snapshot resources not supported")
 }