cephfs: use string const for cli error comparison

we should not return the CLI errors in GRPC errors
we need to return proper readable error messages
to the user for better understanding and better
debugging.

updates ceph#1242

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/cephfs/errors.go

@@ -18,27 +18,42 @@ package cephfs
 
 import (
 	"errors"
-	"fmt"
+)
+
+// Error strings for comparison with CLI errors.
+const (
+	// volumeNotFound is returned when a subvolume is not found in CephFS.
+	volumeNotFound = "Error ENOENT"
+	// invalidCommand is returned when a command is not known to the cluster
+	invalidCommand = "Error EINVAL"
+	// snapNotFound is returned when snap name passed is not found in the list
+	// of snapshots for the given image.
+	snapNotFound = "Error ENOENT"
+	// snapProtectionExist is returned when the snapshot is already protected
+	snapProtectionExist = "Error EEXIST"
 )
 
 var (
+	// ErrCloneInProgress is returned when snapshot clone state is `in progress`
+	ErrCloneInProgress = errors.New("in progress")
+
 	// ErrInvalidVolID is returned when a CSI passed VolumeID is not conformant to any known volume ID
 	// formats.
 	ErrInvalidVolID = errors.New("invalid VolumeID")
 	// ErrNonStaticVolume is returned when a volume is detected as not being
 	// statically provisioned.
 	ErrNonStaticVolume = errors.New("volume not static")
-	// ErrVolNotEmpty is returned when a subvolume has snapshots in it.
-	ErrVolNotEmpty = fmt.Errorf("%v", "Error ENOTEMPTY")
+
+	// ErrSnapProtectionExist is returned when the snapshot is already protected
+	ErrSnapProtectionExist = errors.New("snapshot  protection already exists")
+
+	// ErrSnapNotFound is returned when snap name passed is not found in the list
+	// of snapshots for the given image.
+	ErrSnapNotFound = errors.New("snapshot not found")
+
 	// ErrVolumeNotFound is returned when a subvolume is not found in CephFS.
-	ErrVolumeNotFound = fmt.Errorf("%v", "Error ENOENT")
+	ErrVolumeNotFound = errors.New("volume not found")
+
 	// ErrInvalidCommand is returned when a command is not known to the cluster
-	ErrInvalidCommand = fmt.Errorf("%v", "Error EINVAL")
-	// ErrSnapNotFound is returned when snap name passed is not found in the list of snapshots for the
-	// given image.
-	ErrSnapNotFound = fmt.Errorf("%v", "Error ENOENT")
-	// ErrSnapProtectionExist is returned when the snapshot is already protected
-	ErrSnapProtectionExist = fmt.Errorf("%v", "Error EEXIST")
-	// ErrCloneInProgress is returned when snapshot clone state is `in progress`
-	ErrCloneInProgress = fmt.Errorf("in progress")
+	ErrInvalidCommand = errors.New("invalid command")
 )

internal/cephfs/snapshot.go

@@ -127,8 +127,8 @@ func getSnapshotInfo(ctx context.Context, volOptions *volumeOptions, cr *util.Cr
 		"ceph",
 		args[:]...)
 	if err != nil {
-		if strings.Contains(err.Error(), ErrSnapNotFound.Error()) {
-			return snapshotInfo{}, err
+		if strings.Contains(err.Error(), snapNotFound) {
+			return snapshotInfo{}, ErrSnapNotFound
 		}
 		util.ErrorLog(ctx, "failed to get subvolume snapshot info %s %s(%s) in fs %s", string(snapID), string(volID), err, volOptions.FsName)
 		return snapshotInfo{}, err
@@ -158,7 +158,7 @@ func protectSnapshot(ctx context.Context, volOptions *volumeOptions, cr *util.Cr
 		"ceph",
 		args[:]...)
 	if err != nil {
-		if strings.Contains(err.Error(), ErrSnapProtectionExist.Error()) {
+		if strings.Contains(err.Error(), snapProtectionExist) {
 			return nil
 		}
 		util.ErrorLog(ctx, "failed to protect subvolume snapshot %s %s(%s) in fs %s", string(snapID), string(volID), err, volOptions.FsName)
@@ -191,7 +191,7 @@ func unprotectSnapshot(ctx context.Context, volOptions *volumeOptions, cr *util.
 	if err != nil {
 		// Incase the snap is already unprotected we get ErrSnapProtectionExist error code
 		// in that case we are safe and we could discard this error.
-		if strings.Contains(err.Error(), ErrSnapProtectionExist.Error()) {
+		if strings.Contains(err.Error(), snapProtectionExist) {
 			return nil
 		}
 		util.ErrorLog(ctx, "failed to unprotect subvolume snapshot %s %s(%s) in fs %s", string(snapID), string(volID), err, volOptions.FsName)
@@ -230,7 +230,7 @@ func cloneSnapshot(ctx context.Context, parentVolOptions *volumeOptions, cr *uti
 
 	if err != nil {
 		util.ErrorLog(ctx, "failed to clone subvolume snapshot %s %s(%s) in fs %s", string(cloneID), string(volID), err, parentVolOptions.FsName)
-		if strings.HasPrefix(err.Error(), ErrVolumeNotFound.Error()) {
+		if strings.HasPrefix(err.Error(), volumeNotFound) {
 			return ErrVolumeNotFound
 		}
 		return err

internal/cephfs/volume.go

@@ -73,7 +73,7 @@ func getVolumeRootPathCeph(ctx context.Context, volOptions *volumeOptions, cr *u
 
 	if err != nil {
 		util.ErrorLog(ctx, "failed to get the rootpath for the vol %s(%s) stdError %s", string(volID), err, stderr)
-		if strings.Contains(stderr, ErrVolumeNotFound.Error()) {
+		if strings.Contains(stderr, volumeNotFound) {
 			return "", util.JoinErrors(ErrVolumeNotFound, err)
 		}
 
@@ -101,11 +101,11 @@ func getSubVolumeInfo(ctx context.Context, volOptions *volumeOptions, cr *util.C
 		"--keyfile="+cr.KeyFile)
 	if err != nil {
 		util.ErrorLog(ctx, "failed to get subvolume info for the vol %s(%s)", string(volID), err)
-		if strings.HasPrefix(err.Error(), ErrVolumeNotFound.Error()) {
+		if strings.HasPrefix(err.Error(), volumeNotFound) {
 			return info, ErrVolumeNotFound
 		}
 		// Incase the error is other than invalid command return error to the caller.
-		if !strings.Contains(err.Error(), ErrInvalidCommand.Error()) {
+		if !strings.Contains(err.Error(), invalidCommand) {
 			return info, ErrInvalidCommand
 		}
 
@@ -222,7 +222,7 @@ func resizeVolume(ctx context.Context, volOptions *volumeOptions, cr *util.Crede
 			return nil
 		}
 		// Incase the error is other than invalid command return error to the caller.
-		if !strings.Contains(err.Error(), ErrInvalidCommand.Error()) {
+		if !strings.Contains(err.Error(), invalidCommand) {
 			util.ErrorLog(ctx, "failed to resize subvolume %s(%s) in fs %s", string(volID), err, volOptions.FsName)
 			return err
 		}
@@ -252,7 +252,7 @@ func purgeVolume(ctx context.Context, volID volumeID, cr *util.Credentials, volO
 	err := execCommandErr(ctx, "ceph", arg...)
 	if err != nil {
 		util.ErrorLog(ctx, "failed to purge subvolume %s(%s) in fs %s", string(volID), err, volOptions.FsName)
-		if strings.Contains(err.Error(), ErrVolumeNotFound.Error()) {
+		if strings.Contains(err.Error(), volumeNotFound) {
 			return util.JoinErrors(ErrVolumeNotFound, err)
 		}
 		return err