Function checkDaemonIsSwarmManager

cli/command/stack/deploy.go:101–110

checkDaemonIsSwarmManager does an Info API call to verify that the daemon is a swarm manager. This is necessary because we must create networks before we create services, but the API call for creating a network does not return a proper status code when it can't create a network in the "global" scope

(ctx context.Context, dockerCli command.Cli)

// create services, but the API call for creating a network does not return a
// proper status code when it can't create a network in the "global" scope.
func checkDaemonIsSwarmManager(ctx context.Context, dockerCli command.Cli) error {
	res, err := dockerCli.Client().Info(ctx, client.InfoOptions{})
	if err != nil {
		return err
	}
	if !res.Info.Swarm.ControlAvailable {
		return errors.New(`this node is not a swarm manager. Use "docker swarm init" or "docker swarm join" to connect this node to swarm and try again`)
	}
	return nil
}

// pruneServices removes services that are no longer referenced in the source
func pruneServices(ctx context.Context, dockerCLI command.Cli, namespace convert.Namespace, services map[string]struct{}) {