Add error codes and address comments

Author: xing-yang

csi.proto

@@ -388,6 +388,10 @@ message CreateVolumeRequest {
   // VOLUME_ACCESSIBILITY_CONSTRAINTS plugin capability, the SP MAY
   // choose where the provisioned volume is accessible from.
   TopologyRequirement accessibility_requirements = 7;
+
+  // The ID of the volume group where the volume will be added to.
+  // This field is OPTIONAL.
+  string volume_group_id = 8;
 }
 
 // Specifies what source the volume will be created from. One of the
@@ -588,6 +592,10 @@ message Volume {
   // Indicates a volume accessible from both "zone" "Z2" and "zone" "Z3"
   // in the "region" "R1".
   repeated Topology accessible_topology = 5;
+
+  // The ID of the volume group where the volume belongs to.
+  // This field is OPTIONAL.
+  string volume_group_id = 6;
 }
 
 message TopologyRequirement {
@@ -1069,18 +1077,6 @@ message CreateVolumeGroupRequest {
   // This field is OPTIONAL. Refer to the `Secrets Requirements`
   // section on how to use this field.
   map<string, string> secrets = 3 [(csi_secret) = true];
-
-  // Phase 2
-  // If specified, a volume group will be created from the source group
-  // snapshot.
-  // This field is OPTIONAL.
-  // VolumeGroupSnapshot source_volume_group_snapshot = 4;
-
-  // Phase 2
-  // If specified, a volume group will be created from a list of
-  // existing volumes.
-  // This field is OPTIONAL.
-  // repeated string volume_id = 5;
 }
 
 message CreateVolumeGroupResponse {
@@ -1111,15 +1107,12 @@ message VolumeGroup {
   //   VolumeGroup is not empty.
   // - Response from ModifyVolumeGroup if the VolumeGroup is not
   //   empty after modification.
-  // - Phase 2: Create a new volume group from a source group snapshot.
-  // - Phase 2: Create a new volume group and add a list of existing
-  //   volumes to the group.
   repeated .csi.v1.Volume volumes = 3;
 }
 message DeleteVolumeGroupRequest {
   option (alpha_message) = true;
 
-  // The ID of the volume group to be deprovisioned.
+  // The ID of the volume group to be deleted.
   // This field is REQUIRED.
   string volume_group_id = 1;
 
@@ -1149,6 +1142,12 @@ message ModifyVolumeGroupRequest {
   // be removed from the group.
   // This field is OPTIONAL.
   repeated string volume_ids = 2;
+
+  // Secrets required by plugin to complete volume group
+  // modification request.
+  // This field is OPTIONAL. Refer to the `Secrets Requirements`
+  // section on how to use this field.
+  map<string, string> secrets = 3 [(csi_secret) = true];
 }
 
 message ModifyVolumeGroupResponse {
@@ -1165,6 +1164,12 @@ message ControllerGetVolumeGroupRequest {
   // information for.
   // This field is REQUIRED.
   string volume_group_id = 1;
+
+  // Secrets required by plugin to complete ControllerGetVolumeGroup
+  // request.
+  // This field is OPTIONAL. Refer to the `Secrets Requirements`
+  // section on how to use this field.
+  map<string, string> secrets = 2 [(csi_secret) = true];
 }
 
 message ControllerGetVolumeGroupResponse {
@@ -1191,6 +1196,11 @@ message ListVolumeGroupsRequest {
   // the next page of entries. This field is OPTIONAL.
   // An empty string is equal to an unspecified field value.
   string starting_token = 2;
+
+  // Secrets required by plugin to complete ListVolumeGroup request.
+  // This field is OPTIONAL. Refer to the `Secrets Requirements`
+  // section on how to use this field.
+  map<string, string> secrets = 3 [(csi_secret) = true];
 }
 
 message ListVolumeGroupsResponse {
@@ -1282,7 +1292,7 @@ message VolumeGroupSnapshot {
 message DeleteVolumeGroupSnapshotRequest {
   option (alpha_message) = true;
 
-  // The ID of the group snapshot to be deprovisioned.
+  // The ID of the group snapshot to be deleted.
   // This field is REQUIRED.
   string group_snapshot_id = 1;
 
@@ -1303,6 +1313,12 @@ message ControllerGetVolumeGroupSnapshotRequest {
   // information for.
   // This field is REQUIRED.
   string group_snapshot_id = 1;
+
+  // Secrets required by plugin to complete
+  // ControllerGetVolumeGroupSnapshot request.
+  // This field is OPTIONAL. Refer to the `Secrets Requirements`
+  // section on how to use this field.
+  map<string, string> secrets = 2 [(csi_secret) = true];
 }
 
 message ControllerGetVolumeGroupSnapshotResponse {
@@ -1329,6 +1345,12 @@ message ListVolumeGroupSnapshotsRequest {
   // call to get the next page of entries. This field is OPTIONAL.
   // An empty string is equal to an unspecified field value.
   string starting_token = 2;
+
+  // Secrets required by plugin to complete ListVolumeGroupSnapshot
+  // request.
+  // This field is OPTIONAL. Refer to the `Secrets Requirements`
+  // section on how to use this field.
+  map<string, string> secrets = 3 [(csi_secret) = true];
 }
 
 message ListVolumeGroupSnapshotsResponse {
@@ -1537,6 +1559,10 @@ message Snapshot {
   // `volume_content_source` in a `CreateVolumeRequest`. The default
   // value is false. This field is REQUIRED.
   bool ready_to_use = 5;
+
+  // The ID of the volume group snapshot that this snapshot is part of.
+  // This field is OPTIONAL.
+  string group_snapshot_id = 6;
 }
 message DeleteSnapshotRequest {
   // The ID of the snapshot to be deleted.