Merge pull request moby#48669 from thaJeztah/daemon_fix_restore

daemon: fix restoring containers with name matching an ID

daemon/names.go

@@ -20,11 +20,13 @@ var (
 )
 
 func (daemon *Daemon) registerName(container *container.Container) error {
-	if daemon.Exists(container.ID) {
-		return fmt.Errorf("Container is already loaded")
+	if container.ID == "" {
+		return fmt.Errorf("invalid empty id")
 	}
-	if err := validateID(container.ID); err != nil {
-		return err
+	if daemon.containers.Get(container.ID) != nil {
+		// TODO(thaJeztah): should this be a panic (duplicate IDs due to invalid state on disk?)
+		// TODO(thaJeztah): should this also check for container.ID being a prefix of another container's ID? (daemon.containersReplica.GetByPrefix); only should happen due to corruption / truncated ID.
+		return fmt.Errorf("container is already loaded")
 	}
 	if container.Name == "" {
 		name, err := daemon.generateAndReserveName(container.ID)
@@ -106,10 +108,3 @@ func (daemon *Daemon) generateAndReserveName(id string) (string, error) {
 	}
 	return name, nil
 }
-
-func validateID(id string) error {
-	if id == "" {
-		return fmt.Errorf("Invalid empty id")
-	}
-	return nil
-}