Add a new "is-task" ps filter

This makes it easier to list containers that are part of a task
(swarm mode) and those who are not.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

contrib/completion/bash/docker

@@ -2181,6 +2181,10 @@ _docker_ps() {
 			__docker_complete_container_ids
 			return
 			;;
+		is-task)
+			COMPREPLY=( $( compgen -W "true false" -- "${cur##*=}" ) )
+			return
+			;;
 		name)
 			cur="${cur##*=}"
 			__docker_complete_container_names

contrib/completion/zsh/_docker

@@ -333,6 +333,9 @@ __docker_complete_ps_filters() {
             (id)
                 __docker_containers_ids && ret=0
                 ;;
+            (is-task)
+                _describe -t boolean-filter-opts "filter options" boolean_opts && ret=0
+                ;;
             (name)
                 __docker_containers_names && ret=0
                 ;;

docs/reference/commandline/ps.md

@@ -27,6 +27,7 @@ Options:
                         - since=(<container-name>|<container-id>)
                         - ancestor=(<image-name>[:tag]|<image-id>|<image@digest>)
                           containers created from an image or a descendant.
+                        - is-task=(true|false)
       --format string   Pretty-print containers using a Go template
       --help            Print usage
   -n, --last int        Show n last created containers (includes all states) (default -1)

man/docker-ps.1.md

@@ -32,6 +32,7 @@ the running containers.
    - status=(created|restarting|running|paused|exited|dead)
    - name=<string> a container's name
    - id=<ID> a container's ID
+   - is-task=(true|false) - containers that are a task (part of a service managed by swarm)
    - before=(<container-name>|<container-id>)
    - since=(<container-name>|<container-id>)
    - ancestor=(<image-name>[:tag]|<image-id>|<image@digest>) - containers created from an image or a descendant.