Add --hash opt for config command

Signed-off-by: Fender William <fender.william@gmail.com>

.gitignore

@@ -13,3 +13,4 @@ compose/GITSHA
 *.swp
 .DS_Store
 .cache
+.idea

compose/cli/main.py

@@ -328,7 +328,8 @@ class TopLevelCommand(object):
                                      anything.
             --services               Print the service names, one per line.
             --volumes                Print the volume names, one per line.
-
+            --hash="all"             Print the service config hash, one per line.
+                                     Set "service1,service2" for a list of specified services.
         """
 
         compose_config = get_config_from_options(self.project_dir, self.toplevel_options)
@@ -350,6 +351,20 @@ class TopLevelCommand(object):
             print('\n'.join(volume for volume in compose_config.volumes))
             return
 
+        if options['--hash'] is not None:
+            self.project = project_from_options('.', self.toplevel_options)
+            if options['--hash'] == "all":
+                for service in self.project.services:
+                    print('{} {}'.format(service.name, service.config_hash))
+            else:
+                for service_name in options['--hash'].split(','):
+                    try:
+                        print('{} {}'.format(service_name,
+                                             self.project.get_service(service_name).config_hash))
+                    except NoSuchService as s:
+                        print('{}'.format(s))
+            return
+
         print(serialize_config(compose_config, image_digests))
 
     def create(self, options):

contrib/completion/bash/docker-compose

@@ -136,7 +136,7 @@ _docker_compose_bundle() {
 
 
 _docker_compose_config() {
-	COMPREPLY=( $( compgen -W "--help --quiet -q --resolve-image-digests --services --volumes" -- "$cur" ) )
+	COMPREPLY=( $( compgen -W "--help --quiet -q --resolve-image-digests --services --volumes --hash" -- "$cur" ) )
 }
 
 

contrib/completion/zsh/_docker-compose

@@ -213,7 +213,8 @@ __docker-compose_subcommand() {
                 '(--quiet -q)'{--quiet,-q}"[Only validate the configuration, don't print anything.]" \
                 '--resolve-image-digests[Pin image tags to digests.]' \
                 '--services[Print the service names, one per line.]' \
-                '--volumes[Print the volume names, one per line.]' && ret=0
+                '--volumes[Print the volume names, one per line.]' \
+                '--hash[Print the service config hash, one per line. Set "service1,service2" for a list of specified services.]' \ && ret=0
             ;;
         (create)
             _arguments \