Support --new in generate_systemd (#334)

* Support --new in generate_systemd

Fixes #318.

* Add docs

plugins/module_utils/podman/common.py

@@ -46,6 +46,8 @@ def generate_systemd(module, module_params, name):
         command.extend(['--no-header'])
     if sysconf.get('names', True):
         command.extend(['--name'])
+    if sysconf.get("new"):
+        command.extend(["--new"])
     if sysconf.get('container_prefix') is not None:
         command.extend(['--container-prefix=%s' % sysconf['container_prefix']])
     if sysconf.get('pod_prefix') is not None:

plugins/modules/podman_container.py

@@ -351,6 +351,13 @@ options:
             container/pod and the prefix. The default is "-" (dash).
         type: str
         required: false
+      new:
+        description:
+          - Create containers and pods when the unit is started instead of
+            expecting them to exist. The default is "false".
+            Refer to podman-generate-systemd(1) for more information.
+        type: bool
+        default: false
   gidmap:
     description:
       - Run the container in a new user namespace using the supplied mapping.