Remove named volumes during "down -v"

Fixes containers#105

Signed-off-by: Luiz Carvalho <lucarval@redhat.com>

podman_compose.py

@@ -820,6 +820,13 @@ class Podman:
             time.sleep(sleep)
         return p
 
+    def volume_inspect_all(self):
+        output = self.output(["volume", "inspect", "--all"]).decode('utf-8')
+        return json.loads(output)
+
+    def volume_rm(self, name):
+        return self.run(["volume", "rm", name])
+
 def normalize_service(service):
     for key in ("env_file", "security_opt"):
         if key not in service: continue
@@ -1414,6 +1421,12 @@ def compose_down(compose, args):
         return
     for pod in compose.pods:
         compose.podman.run([], "pod", ["rm", pod["name"]], sleep=0)
+    if args.volumes:
+        volumes = compose.podman.volume_inspect_all()
+        for volume in volumes:
+            project = volume.get("Labels", {}).get("io.podman.compose.project")
+            if project == compose.project_name:
+                compose.podman.volume_rm(volume["Name"])
 
 @cmd_run(podman_compose, 'ps', 'show status of containers')
 def compose_ps(compose, args):
@@ -1573,6 +1586,12 @@ def compose_up_parse(parser):
     parser.add_argument("--exit-code-from", metavar='SERVICE', type=str, default=None,
         help="Return the exit code of the selected service container. Implies --abort-on-container-exit.")
 
+@cmd_parse(podman_compose, 'down')
+def compose_down_parse(parser):
+    parser.add_argument("-v", "--volumes", action='store_true', default=False,
+        help="Remove named volumes declared in the `volumes` section of the Compose file and "
+             "anonymous volumes attached to containers.")
+
 @cmd_parse(podman_compose, 'run')
 def compose_run_parse(parser):
     parser.add_argument("-d", "--detach", action='store_true',