Support multiple service IDs on "docker service ps"

This fix tries to address issue raised in 25228 to support
multiple service IDs on `docker service ps`.

Multiple IDs are allowed with `docker service ps ...`, and
related documentation has been updated.

A test has been added to cover the changes.

This fix fixes 25228.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

command/service/ps.go

@@ -1,7 +1,13 @@
 package service
 
 import (
+	"fmt"
+	"strings"
+
+	"golang.org/x/net/context"
+
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/cli/command/idresolver"
@@ -9,11 +15,10 @@ import (
 	"github.com/docker/docker/cli/command/task"
 	"github.com/docker/docker/opts"
 	"github.com/spf13/cobra"
-	"golang.org/x/net/context"
 )
 
 type psOptions struct {
-	serviceID string
+	services  []string
 	quiet     bool
 	noResolve bool
 	noTrunc   bool
@@ -24,11 +29,11 @@ func newPsCommand(dockerCli *command.DockerCli) *cobra.Command {
 	opts := psOptions{filter: opts.NewFilterOpt()}
 
 	cmd := &cobra.Command{
-		Use:   "ps [OPTIONS] SERVICE",
-		Short: "List the tasks of a service",
-		Args:  cli.ExactArgs(1),
+		Use:   "ps [OPTIONS] SERVICE [SERVICE...]",
+		Short: "List the tasks of one or more services",
+		Args:  cli.RequiresMinArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
-			opts.serviceID = args[0]
+			opts.services = args
 			return runPS(dockerCli, opts)
 		},
 	}
@@ -45,13 +50,46 @@ func runPS(dockerCli *command.DockerCli, opts psOptions) error {
 	client := dockerCli.Client()
 	ctx := context.Background()
 
-	service, _, err := client.ServiceInspectWithRaw(ctx, opts.serviceID)
+	filter := opts.filter.Value()
+
+	serviceIDFilter := filters.NewArgs()
+	serviceNameFilter := filters.NewArgs()
+	for _, service := range opts.services {
+		serviceIDFilter.Add("id", service)
+		serviceNameFilter.Add("name", service)
+	}
+	serviceByIDList, err := client.ServiceList(ctx, types.ServiceListOptions{Filters: serviceIDFilter})
+	if err != nil {
+		return err
+	}
+	serviceByNameList, err := client.ServiceList(ctx, types.ServiceListOptions{Filters: serviceNameFilter})
 	if err != nil {
 		return err
 	}
 
-	filter := opts.filter.Value()
-	filter.Add("service", service.ID)
+	for _, service := range opts.services {
+		serviceCount := 0
+		// Lookup by ID/Prefix
+		for _, serviceEntry := range serviceByIDList {
+			if strings.HasPrefix(serviceEntry.ID, service) {
+				filter.Add("service", serviceEntry.ID)
+				serviceCount++
+			}
+		}
+
+		// Lookup by Name/Prefix
+		for _, serviceEntry := range serviceByNameList {
+			if strings.HasPrefix(serviceEntry.Spec.Annotations.Name, service) {
+				filter.Add("service", serviceEntry.ID)
+				serviceCount++
+			}
+		}
+		// If nothing has been found, return immediately.
+		if serviceCount == 0 {
+			return fmt.Errorf("no such services: %s", service)
+		}
+	}
+
 	if filter.Include("node") {
 		nodeFilters := filter.Get("node")
 		for _, nodeFilter := range nodeFilters {