add --detach to docker scale

Signed-off-by: Victor Vieux <victorvieux@gmail.com>

cli/command/service/scale.go

@@ -12,17 +12,28 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
 )
 
+type scaleOptions struct {
+	detach bool
+}
+
 func newScaleCommand(dockerCli *command.DockerCli) *cobra.Command {
-	return &cobra.Command{
+	options := &scaleOptions{}
+
+	cmd := &cobra.Command{
 		Use:   "scale SERVICE=REPLICAS [SERVICE=REPLICAS...]",
 		Short: "Scale one or multiple replicated services",
 		Args:  scaleArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return runScale(dockerCli, args)
+			return runScale(dockerCli, cmd.Flags(), options, args)
 		},
 	}
+
+	flags := cmd.Flags()
+	addDetachFlag(flags, &options.detach)
+	return cmd
 }
 
 func scaleArgs(cmd *cobra.Command, args []string) error {
@@ -43,8 +54,10 @@ func scaleArgs(cmd *cobra.Command, args []string) error {
 	return nil
 }
 
-func runScale(dockerCli *command.DockerCli, args []string) error {
+func runScale(dockerCli *command.DockerCli, flags *pflag.FlagSet, options *scaleOptions, args []string) error {
 	var errs []string
+	ctx := context.Background()
+
 	for _, arg := range args {
 		parts := strings.SplitN(arg, "=", 2)
 		serviceID, scaleStr := parts[0], parts[1]
@@ -56,9 +69,21 @@ func runScale(dockerCli *command.DockerCli, args []string) error {
 			continue
 		}
 
-		if err := runServiceScale(dockerCli, serviceID, scale); err != nil {
+		if err := runServiceScale(ctx, dockerCli, serviceID, scale); err != nil {
 			errs = append(errs, fmt.Sprintf("%s: %v", serviceID, err))
 		}
+
+		if options.detach {
+			continue
+		}
+
+		if err := waitOnService(ctx, dockerCli, serviceID, false); err != nil {
+			errs = append(errs, fmt.Sprintf("%s: %v", serviceID, err))
+		}
+	}
+
+	if options.detach {
+		warnDetachDefault(dockerCli.Err(), dockerCli.Client().ClientVersion(), flags, "scaled")
 	}
 
 	if len(errs) == 0 {
@@ -67,9 +92,8 @@ func runScale(dockerCli *command.DockerCli, args []string) error {
 	return errors.Errorf(strings.Join(errs, "\n"))
 }
 
-func runServiceScale(dockerCli *command.DockerCli, serviceID string, scale uint64) error {
+func runServiceScale(ctx context.Context, dockerCli *command.DockerCli, serviceID string, scale uint64) error {
 	client := dockerCli.Client()
-	ctx := context.Background()
 
 	service, _, err := client.ServiceInspectWithRaw(ctx, serviceID, types.ServiceInspectOptions{})
 	if err != nil {

docs/reference/commandline/service_scale.md

@@ -16,11 +16,12 @@ keywords: "service, scale"
 # service scale
 
 ```markdown
-Usage:  docker service scale SERVICE=REPLICAS [SERVICE=REPLICAS...]
+Usage:  docker service scale [OPTIONS] SERVICE=REPLICAS [SERVICE=REPLICAS...]
 
 Scale one or multiple replicated services
 
 Options:
+  -d, --detach                             Exit immediately instead of waiting for the service to converge (default true)
       --help   Print usage
 ```