lxd/images: Support retrying image record deletion in autoUpdateImages

Previously the tx.DeleteImage error was not returned to the calling s.DB.Cluster.Transaction
function which meant the built in retry logic LXD has when the table is locked was not being
used. Instead return the error and let the retry mechanisms have a go at retrying the request.

Signed-off-by: Thomas Parrott <thomas.parrott@canonical.com>

Author: tomponline

lxd/images.go

@@ -2004,17 +2004,20 @@ func autoUpdateImages(ctx context.Context, s *state.State) error {
 				}
 			}
 
-			_ = s.DB.Cluster.Transaction(context.TODO(), func(ctx context.Context, tx *db.ClusterTx) error {
+			err = s.DB.Cluster.Transaction(context.TODO(), func(ctx context.Context, tx *db.ClusterTx) error {
 				for _, ID := range deleteIDs {
 					// Remove the database entry for the image after distributing to cluster members.
 					err := tx.DeleteImage(ctx, ID)
 					if err != nil {
-						logger.Error("Error deleting old image from database", logger.Ctx{"member": s.ServerName, "fingerprint": fingerprint, "ID": ID, "err": err})
+						return fmt.Errorf(`Failed deleting image record with ID "%d": %w`, ID, err)
 					}
 				}
 
 				return nil
 			})
+			if err != nil {
+				logger.Error("Error deleting old image(s) records", logger.Ctx{"member": s.ServerName, "fingerprint": fingerprint, "err": err})
+			}
 		}
 	}