Handle Delete operation if pool not found

If the backend rbd or cephfs pool is already deleted
we need to return success to the  DeleteVolume RPC
call to make it idempotent.

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

pkg/util/cephcmds.go

@@ -114,7 +114,7 @@ func GetPoolName(ctx context.Context, monitors string, cr *Credentials, poolID i
 		}
 	}
 
-	return "", fmt.Errorf("pool ID (%d) not found in Ceph cluster", poolID)
+	return "", ErrPoolNotFound{string(poolID), fmt.Errorf("pool ID (%d) not found in Ceph cluster", poolID)}
 }
 
 // SetOMapKeyValue sets the given key and value into the provided Ceph omap name

pkg/util/errors.go

@@ -56,3 +56,13 @@ type ErrSnapNameConflict struct {
 func (e ErrSnapNameConflict) Error() string {
 	return e.err.Error()
 }
+
+// ErrPoolNotFound is returned when pool is not found
+type ErrPoolNotFound struct {
+	Pool string
+	Err  error
+}
+
+func (e ErrPoolNotFound) Error() string {
+	return e.Err.Error()
+}