API change to improve VolumeGroupSnapshot restore

Change `VolumeSnapshotRefList` in `VolumeGroupSnapshotStatus` to
`PVCVolumeSnapshotRefList`, allowing users to map a `VolumeSnapshot` to
a specific `PersistentVolumeClaim`.

Change `VolumeSnapshotContentRefList` in
`VolumeGroupSnapshotContentStatus` to `PVVolumeSnapshotContentRefList`,
allowing users to map a `VolumeSnapshotContent` to a specific
`PersistentVolume`.

This two changes allow users to map each `VolumeSnapshot` back to the
original PVC it was taken from.

Author: leonardoce

client/apis/volumegroupsnapshot/v1alpha1/types.go

@@ -103,11 +103,20 @@ type VolumeGroupSnapshotStatus struct {
 	// +optional
 	Error *snapshotv1.VolumeSnapshotError `json:"error,omitempty" protobuf:"bytes,4,opt,name=error,casttype=VolumeSnapshotError"`
 
-	// VolumeSnapshotRefList is the list of volume snapshot references for this
-	// group snapshot.
+	// VolumeSnapshotRefList is the list of PVC and VolumeSnapshot pair that
+	// is part of this group snapshot.
 	// The maximum number of allowed snapshots in the group is 100.
 	// +optional
-	VolumeSnapshotRefList []core_v1.ObjectReference `json:"volumeSnapshotRefList,omitempty" protobuf:"bytes,5,opt,name=volumeSnapshotRefList"`
+	PVCVolumeSnapshotRefList []PVCVolumeSnapshotPair `json:"pvcVolumeSnapshotRefList,omitempty" protobuf:"bytes,6,opt,name=pvcVolumeSnapshotRefList"`
+}
+
+// PVCVolumeSnapshotPair defines a pair of a PVC reference and a Volume Snapshot
+type PVCVolumeSnapshotPair struct {
+	// PersistentVolumeClaimRef is a reference to the PVC this pair is referring to
+	PersistentVolumeClaimRef core_v1.ObjectReference `json:"persistentVolumeClaimRef,omitempty" protobuf:"bytes,1,opt,name=persistentVolumeClaimRef"`
+
+	// VolumeSnapshotRef is a reference to the VolumeSnapshot this pair is referring to
+	VolumeSnapshotRef core_v1.ObjectReference `json:"volumeSnapshotRef,omitempty" protobuf:"bytes,1,opt,name=volumeSnapshotRef"`
 }
 
 //+genclient
@@ -337,11 +346,21 @@ type VolumeGroupSnapshotContentStatus struct {
 	// +optional
 	Error *snapshotv1.VolumeSnapshotError `json:"error,omitempty" protobuf:"bytes,4,opt,name=error,casttype=VolumeSnapshotError"`
 
-	// VolumeSnapshotContentRefList is the list of volume snapshot content references
-	// for this group snapshot.
+	// PVVolumeSnapshotContentRefList is the list of pairs of PV and
+	// VolumeSnapshotCOntent for this group snapshot
 	// The maximum number of allowed snapshots in the group is 100.
 	// +optional
-	VolumeSnapshotContentRefList []core_v1.ObjectReference `json:"volumeSnapshotContentRefList,omitempty" protobuf:"bytes,5,opt,name=volumeSnapshotContentRefList"`
+	PVVolumeSnapshotContentRefList []PVVolumeSnapshotContentPair `json:"pvVolumeSnapshotContentRefList,omitempty" protobuf:"bytes,6,opt,name=pvVolumeSnapshotContentRefList"`
+}
+
+// PVVolumeSnapshotContentPair represent a pair of PV names and
+// VolumeSnapshotContent names
+type PVVolumeSnapshotContentPair struct {
+	// PersistentVolumeName is the name of the persistent volume
+	PersistentVolumeName string `json:"persistentVolumeName,omitempty" protobuf:"bytes,1,opt,name=persistentVolumeName"`
+
+	// VolumeSnapshotContentName is the name of the volume snapshot content resource
+	VolumeSnapshotContentName string `json:"volumeSnapshotContentName,omitempty" protobuf:"bytes,1,opt,name=volumeSnapshotContentName"`
 }
 
 // VolumeGroupSnapshotContentSource represents the CSI source of a group snapshot.

client/apis/volumegroupsnapshot/v1alpha1/zz_generated.deepcopy.go

@@ -3,7 +3,7 @@ apiVersion: apiextensions.k8s.io/v1
 kind: CustomResourceDefinition
 metadata:
   annotations:
-    api-approved.kubernetes.io: "https://github.com/kubernetes-csi/external-snapshotter/pull/971"
+    api-approved.kubernetes.io: "https://github.com/kubernetes-csi/external-snapshotter/pull/1068"
     controller-gen.kubebuilder.io/version: v0.12.0
   creationTimestamp: null
   name: volumegroupsnapshotcontents.groupsnapshot.storage.k8s.io
@@ -227,6 +227,24 @@ spec:
                     format: date-time
                     type: string
                 type: object
+              pvVolumeSnapshotContentRefList:
+                description: PVVolumeSnapshotContentRefList is the list of pairs of
+                  PV and VolumeSnapshotCOntent for this group snapshot The maximum
+                  number of allowed snapshots in the group is 100.
+                items:
+                  description: PVVolumeSnapshotContentPair represent a pair of PV
+                    names and VolumeSnapshotContent names
+                  properties:
+                    persistentVolumeName:
+                      description: PersistentVolumeName is the name of the persistent
+                        volume
+                      type: string
+                    volumeSnapshotContentName:
+                      description: VolumeSnapshotContentName is the name of the volume
+                        snapshot content resource
+                      type: string
+                  type: object
+                type: array
               readyToUse:
                 description: ReadyToUse indicates if all the individual snapshots
                   in the group are ready to be used to restore a group of volumes.
@@ -239,72 +257,6 @@ spec:
                   system. If a storage system does not provide such an id, the CSI
                   driver can choose to return the VolumeGroupSnapshot name.
                 type: string
-              volumeSnapshotContentRefList:
-                description: VolumeSnapshotContentRefList is the list of volume snapshot
-                  content references for this group snapshot. The maximum number of
-                  allowed snapshots in the group is 100.
-                items:
-                  description: "ObjectReference contains enough information to let
-                    you inspect or modify the referred object. --- New uses of this
-                    type are discouraged because of difficulty describing its usage
-                    when embedded in APIs. 1. Ignored fields.  It includes many fields
-                    which are not generally honored.  For instance, ResourceVersion
-                    and FieldPath are both very rarely valid in actual usage. 2. Invalid
-                    usage help.  It is impossible to add specific help for individual
-                    usage.  In most embedded usages, there are particular restrictions
-                    like, \"must refer only to types A and B\" or \"UID not honored\"
-                    or \"name must be restricted\". Those cannot be well described
-                    when embedded. 3. Inconsistent validation.  Because the usages
-                    are different, the validation rules are different by usage, which
-                    makes it hard for users to predict what will happen. 4. The fields
-                    are both imprecise and overly precise.  Kind is not a precise
-                    mapping to a URL. This can produce ambiguity during interpretation
-                    and require a REST mapping.  In most cases, the dependency is
-                    on the group,resource tuple and the version of the actual struct
-                    is irrelevant. 5. We cannot easily change it.  Because this type
-                    is embedded in many locations, updates to this type will affect
-                    numerous schemas.  Don't make new APIs embed an underspecified
-                    API type they do not control. \n Instead of using this type, create
-                    a locally provided and used type that is well-focused on your
-                    reference. For example, ServiceReferences for admission registration:
-                    https://github.com/kubernetes/api/blob/release-1.17/admissionregistration/v1/types.go#L533
-                    ."
-                  properties:
-                    apiVersion:
-                      description: API version of the referent.
-                      type: string
-                    fieldPath:
-                      description: 'If referring to a piece of an object instead of
-                        an entire object, this string should contain a valid JSON/Go
-                        field access statement, such as desiredState.manifest.containers[2].
-                        For example, if the object reference is to a container within
-                        a pod, this would take on a value like: "spec.containers{name}"
-                        (where "name" refers to the name of the container that triggered
-                        the event) or if no container name is specified "spec.containers[2]"
-                        (container with index 2 in this pod). This syntax is chosen
-                        only to have some well-defined way of referencing a part of
-                        an object. TODO: this design is not final and this field is
-                        subject to change in the future.'
-                      type: string
-                    kind:
-                      description: 'Kind of the referent. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
-                      type: string
-                    name:
-                      description: 'Name of the referent. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#names'
-                      type: string
-                    namespace:
-                      description: 'Namespace of the referent. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/'
-                      type: string
-                    resourceVersion:
-                      description: 'Specific resourceVersion to which this reference
-                        is made, if any. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#concurrency-control-and-consistency'
-                      type: string
-                    uid:
-                      description: 'UID of the referent. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#uids'
-                      type: string
-                  type: object
-                  x-kubernetes-map-type: atomic
-                type: array
             type: object
         required:
         - spec