Merge pull request #27596 from aaronlehmann/rolling-restart

Add force option to service update

command/service/update.go

@@ -37,6 +37,7 @@ func newUpdateCommand(dockerCli *command.DockerCli) *cobra.Command {
 	flags.String("image", "", "Service image tag")
 	flags.String("args", "", "Service command args")
 	flags.Bool("rollback", false, "Rollback to previous specification")
+	flags.Bool("force", false, "Force update even if no changes require it")
 	addServiceFlags(cmd, opts)
 
 	flags.Var(newListOptsVar(), flagEnvRemove, "Remove an environment variable")
@@ -257,6 +258,15 @@ func updateService(flags *pflag.FlagSet, spec *swarm.ServiceSpec) error {
 		return err
 	}
 
+	force, err := flags.GetBool("force")
+	if err != nil {
+		return err
+	}
+
+	if force {
+		spec.TaskTemplate.ForceUpdate++
+	}
+
 	return nil
 }