[cinder-csi-plugin] Refactor list volumes (#2766)

* refactor list volumes call

* upgrade tests

* comments improvements

* fix imports and list options

* token split

* add more jointoken  tests

Author: kon-angelo

pkg/csi/cinder/controllerserver.go

@@ -18,8 +18,8 @@ package cinder
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
+	"slices"
 	"sort"
 	"strconv"
 
@@ -126,7 +126,7 @@ func (cs *controllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 
 	// Volume Create
 	properties := map[string]string{cinderCSIClusterIDKey: cs.Driver.clusterID}
-	//Tag volume with metadata if present: https://github.com/kubernetes-csi/external-provisioner/pull/399
+	// Tag volume with metadata if present: https://github.com/kubernetes-csi/external-provisioner/pull/399
 	for _, mKey := range sharedcsi.RecognizedCSIProvisionerParams {
 		if v, ok := req.Parameters[mKey]; ok {
 			properties[mKey] = v
@@ -161,7 +161,7 @@ func (cs *controllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 			var back *backups.Backup
 			back, err = cloud.GetBackupByID(ctx, snapshotID)
 			if err != nil {
-				//If there is an error getting the backup as well, fail.
+				// If there is an error getting the backup as well, fail.
 				return nil, status.Errorf(codes.NotFound, "VolumeContentSource Snapshot or Backup with ID %s not found", snapshotID)
 			}
 			if back.Status != "available" {
@@ -402,12 +402,6 @@ func (cs *controllerServer) ControllerUnpublishVolume(ctx context.Context, req *
 	return &csi.ControllerUnpublishVolumeResponse{}, nil
 }
 
-type CloudsStartingToken struct {
-	CloudName string `json:"cloud"`
-	Token     string `json:"token"`
-	isEmpty   bool
-}
-
 func (cs *controllerServer) extractNodeIDs(attachments []volumes.Attachment) []string {
 	nodeIDs := make([]string, len(attachments))
 	for i, attachment := range attachments {
@@ -439,123 +433,56 @@ func (cs *controllerServer) ListVolumes(ctx context.Context, req *csi.ListVolume
 		return nil, status.Errorf(codes.InvalidArgument, "[ListVolumes] Invalid max entries request %v, must not be negative ", req.MaxEntries)
 	}
 	maxEntries := int(req.MaxEntries)
-
 	var err error
-	var cloudsToken = CloudsStartingToken{
-		CloudName: "",
-		Token:     "",
-		isEmpty:   len(req.StartingToken) == 0,
-	}
 
 	cloudsNames := maps.Keys(cs.Clouds)
 	sort.Strings(cloudsNames)
 
-	currentCloudName := cloudsNames[0]
+	var (
+		token     string
+		idx       int
+		cloudName = cloudsNames[0]
+	)
 	if req.StartingToken != "" {
-		err = json.Unmarshal([]byte(req.StartingToken), &cloudsToken)
-		if err != nil {
-			return nil, status.Errorf(codes.Aborted, "[ListVolumes] Invalid request: Token invalid")
-		}
-		currentCloudName = cloudsToken.CloudName
-	}
-
-	startingToken := cloudsToken.Token
-	var cloudsVentries []*csi.ListVolumesResponse_Entry
-	var vlist []volumes.Volume
-	var nextPageToken string
-
-	if !cloudsToken.isEmpty && startingToken == "" {
-		// previous call ended on last volumes from "currentCloudName" we should pass to next one
-		for i := range cloudsNames {
-			if cloudsNames[i] == currentCloudName {
-				currentCloudName = cloudsNames[i+1]
-				break
-			}
+		token, cloudName = splitToken(req.StartingToken)
+		idx = slices.Index(cloudsNames, cloudName)
+		if idx < 0 {
+			return nil, status.Errorf(codes.Internal, "[ListVolumes] Invalid request: %s", fmt.Errorf("unknown cloud specified in the request: %v", cloudName))
 		}
 	}
 
-	startIdx := 0
-	for _, cloudName := range cloudsNames {
-		if cloudName == currentCloudName {
-			break
-		}
-		startIdx++
-	}
-	for idx := startIdx; idx < len(cloudsNames); idx++ {
-		if maxEntries > 0 {
-			vlist, nextPageToken, err = cs.Clouds[cloudsNames[idx]].ListVolumes(ctx, maxEntries-len(cloudsVentries), startingToken)
-		} else {
-			vlist, nextPageToken, err = cs.Clouds[cloudsNames[idx]].ListVolumes(ctx, maxEntries, startingToken)
-		}
-		startingToken = nextPageToken
-		if err != nil {
-			klog.Errorf("Failed to ListVolumes: %v", err)
-			if cpoerrors.IsInvalidError(err) {
-				return nil, status.Errorf(codes.Aborted, "[ListVolumes] Invalid request: %v", err)
-			}
-			return nil, status.Errorf(codes.Internal, "ListVolumes failed with error %v", err)
-		}
-
-		ventries := cs.createVolumeEntries(vlist)
-		klog.V(4).Infof("ListVolumes: retrieved %d entries and %q next token from cloud %q", len(ventries), nextPageToken, cloudsNames[idx])
-
-		cloudsVentries = append(cloudsVentries, ventries...)
-
-		// Reach maxEntries setup nextToken with cloud identifier if needed
-		sendEmptyToken := false
-		if maxEntries > 0 && len(cloudsVentries) == maxEntries {
-			if nextPageToken == "" {
-				if idx+1 == len(cloudsNames) {
-					// no more entries and no more clouds
-					// send no token its finished
-					klog.V(4).Infof("ListVolumes: completed with %d entries and %q next token", len(cloudsVentries), "")
-					return &csi.ListVolumesResponse{
-						Entries:   cloudsVentries,
-						NextToken: "",
-					}, nil
-				} else {
-					// still clouds to process
-					// set token to next non empty cloud
-					i := 0
-					for i = idx + 1; i < len(cloudsNames); i++ {
-						vlistTmp, _, err := cs.Clouds[cloudsNames[i]].ListVolumes(ctx, 1, "")
-						if err != nil {
-							klog.Errorf("Failed to ListVolumes: %v", err)
-							if cpoerrors.IsInvalidError(err) {
-								return nil, status.Errorf(codes.Aborted, "[ListVolumes] Invalid request: %v", err)
-							}
-							return nil, status.Errorf(codes.Internal, "ListVolumes failed with error %v", err)
-						}
-						if len(vlistTmp) > 0 {
-							cloudsToken.CloudName = cloudsNames[i]
-							cloudsToken.isEmpty = false
-							break
-						}
-					}
-					if i == len(cloudsNames) {
-						sendEmptyToken = true
-					}
-				}
-			}
-			cloudsToken.CloudName = cloudsNames[idx]
-			cloudsToken.Token = nextPageToken
-			var data []byte
-			data, _ = json.Marshal(cloudsToken)
-			if sendEmptyToken {
-				data = []byte("")
-			}
-			klog.V(4).Infof("ListVolumes: completed with %d entries and %q next token", len(cloudsVentries), string(data))
-			return &csi.ListVolumesResponse{
-				Entries:   cloudsVentries,
-				NextToken: string(data),
-			}, nil
+	var volumeList []volumes.Volume
+	volumeList, token, err = cs.Clouds[cloudName].ListVolumes(ctx, maxEntries, token)
+	if err != nil {
+		klog.Errorf("Failed to ListVolumes: %v", err)
+		if cpoerrors.IsInvalidError(err) {
+			return nil, status.Errorf(codes.Aborted, "[ListVolumes] Invalid request: %v", err)
 		}
+		return nil, status.Errorf(codes.Internal, "ListVolumes failed with error %v", err)
+	}
+	volumeEntries := cs.createVolumeEntries(volumeList)
+	klog.V(4).Infof("ListVolumes: retrieved %d entries and %q next token from cloud %q", len(volumeEntries), token, cloudName)
+
+	switch {
+	// if we have not finished listing all volumes from this cloud, we will continue on next call.
+	case token != "":
+		// if we listed all volumes from this cloud but more clouds exist, return a token of the next cloud.
+	case idx+1 < len(cloudsNames):
+		cloudName = cloudsNames[idx+1]
+	default:
+		// work is done.
+		klog.V(4).Infof("ListVolumes: completed with %d entries and %q next token", len(volumeEntries), "")
+		return &csi.ListVolumesResponse{
+			Entries:   volumeEntries,
+			NextToken: "",
+		}, nil
 	}
 
-	klog.V(4).Infof("ListVolumes: completed with %d entries and %q next token", len(cloudsVentries), "")
+	nextToken := joinToken(token, cloudName)
+	klog.V(4).Infof("ListVolumes: completed with %d entries and %q next token", len(volumeEntries), nextToken)
 	return &csi.ListVolumesResponse{
-		Entries:   cloudsVentries,
-		NextToken: "",
+		Entries:   volumeEntries,
+		NextToken: nextToken,
 	}, nil
 }