@@ -14,6 +14,7 @@ import (

 type psOptions struct {

 	serviceID string

+	quiet     bool

 	noResolve bool

 	noTrunc   bool

 	filter    opts.FilterOpt

@@ -32,6 +33,7 @@ func newPsCommand(dockerCli *command.DockerCli) *cobra.Command {

 		},

 	}

 	flags := cmd.Flags()

+	flags.BoolVarP(&opts.quiet, "quiet", "q", false, "Only display task IDs")

 	flags.BoolVar(&opts.noTrunc, "no-trunc", false, "Do not truncate output")

 	flags.BoolVar(&opts.noResolve, "no-resolve", false, "Do not map IDs to Names")

 	flags.VarP(&opts.filter, "filter", "f", "Filter output based on conditions provided")

@@ -67,5 +69,8 @@ func runPS(dockerCli *command.DockerCli, opts psOptions) error {

 		return err

 	}

+	if opts.quiet {

+		return task.PrintQuiet(dockerCli, tasks)

+	}

 	return task.Print(dockerCli, ctx, tasks, idresolver.New(client, opts.noResolve), opts.noTrunc)

 }

@@ -2,6 +2,7 @@ package task

 import (

 	"fmt"

+	"io"

 	"sort"

 	"strings"

 	"text/tabwriter"

@@ -40,7 +41,9 @@ func (t tasksBySlot) Less(i, j int) bool {

 	return t[j].Meta.CreatedAt.Before(t[i].CreatedAt)

 }

-// Print task information in a table format

+// Print task information in a table format.

+// Besides this, command `docker node ps <node>`

+// and `docker stack ps` will call this, too.

 func Print(dockerCli *command.DockerCli, ctx context.Context, tasks []swarm.Task, resolver *idresolver.IDResolver, noTrunc bool) error {

 	sort.Stable(tasksBySlot(tasks))

@@ -50,6 +53,27 @@ func Print(dockerCli *command.DockerCli, ctx context.Context, tasks []swarm.Task

 	defer writer.Flush()

 	fmt.Fprintln(writer, strings.Join([]string{"NAME", "IMAGE", "NODE", "DESIRED STATE", "CURRENT STATE", "ERROR"}, "\t"))

+	if err := print(writer, ctx, tasks, resolver, noTrunc); err != nil {

+		return err

+	}

+

+	return nil

+}

+

+// PrintQuiet shows task list in a quiet way.

+func PrintQuiet(dockerCli *command.DockerCli, tasks []swarm.Task) error {

+	sort.Stable(tasksBySlot(tasks))

+

+	out := dockerCli.Out()

+

+	for _, task := range tasks {

+		fmt.Fprintln(out, task.ID)

+	}

+

+	return nil

+}

+

+func print(out io.Writer, ctx context.Context, tasks []swarm.Task, resolver *idresolver.IDResolver, noTrunc bool) error {

 	prevServiceName := ""

 	prevSlot := 0

 	for _, task := range tasks {

@@ -94,7 +118,7 @@ func Print(dockerCli *command.DockerCli, ctx context.Context, tasks []swarm.Task

 		}

 		fmt.Fprintf(

-			writer,

+			out,

 			psTaskItemFmt,

 			indentedName,

 			task.Spec.ContainerSpec.Image,

@@ -105,6 +129,5 @@ func Print(dockerCli *command.DockerCli, ctx context.Context, tasks []swarm.Task

 			taskErr,

 		)

 	}

-

 	return nil

 }

@@ -2462,7 +2462,7 @@ _docker_service_ps() {

 	case "$cur" in

 		-*)

-			COMPREPLY=( $( compgen -W "--all -a --filter -f --help --no-resolve --no-trunc" -- "$cur" ) )

+			COMPREPLY=( $( compgen -W "--filter -f --help --no-resolve --no-trunc --quiet -q" -- "$cur" ) )

 			;;

 		*)

 			local counter=$(__docker_pos_first_nonflag '--filter|-f')

@@ -1167,10 +1167,10 @@ __docker_service_subcommand() {

         (ps)

             _arguments $(__docker_arguments) \

                 $opts_help \

-                "($help -a --all)"{-a,--all}"[Display all tasks]" \

                 "($help)*"{-f=,--filter=}"[Provide filter values]:filter:->filter-options" \

                 "($help)--no-resolve[Do not map IDs to Names]" \

                 "($help)--no-trunc[Do not truncate output]" \

+                "($help -q --quiet)"{-q,--quiet}"[Only display task IDs]" \

                 "($help -)1:service:__docker_complete_services" && ret=0

             case $state in

                 (filter-options)

@@ -17,22 +17,21 @@ aliases: ["/engine/reference/commandline/service_tasks/"]

 # service ps

 ```Markdown

-Usage:	docker service ps [OPTIONS] SERVICE

+Usage:  docker service ps [OPTIONS] SERVICE

 List the tasks of a service

 Options:

-  -a, --all            Display all tasks

-  -f, --filter value   Filter output based on conditions provided

-      --help           Print usage

-      --no-resolve     Do not map IDs to Names

-      --no-trunc       Do not truncate output

+  -f, --filter filter   Filter output based on conditions provided

+      --help            Print usage

+      --no-resolve      Do not map IDs to Names

+      --no-trunc        Do not truncate output

+  -q, --quiet           Only display task IDs

 ```

 Lists the tasks that are running as part of the specified service. This command

 has to be run targeting a manager node.

-

 ## Examples

 ### Listing the tasks that are part of a service