Supported group_add

Signed-off-by: George Lester <glester491@gmail.com>

tests/integration/service_test.py

@@ -867,6 +867,14 @@ class ServiceTest(DockerClientTestCase):
         container = create_and_start_container(service)
         self.assertEqual(container.get('HostConfig.OomScoreAdj'), 500)
 
+    def test_group_add_value(self):
+        service = self.create_service('web', group_add=["root", "1"])
+        container = create_and_start_container(service)
+
+        host_container_groupadd = container.get('HostConfig.GroupAdd')
+        self.assertTrue("root" in host_container_groupadd)
+        self.assertTrue("1" in host_container_groupadd)
+
     def test_restart_on_failure_value(self):
         service = self.create_service('web', restart={
             'Name': 'on-failure',

tests/unit/config/config_test.py

@@ -1289,6 +1289,26 @@ class ConfigTest(unittest.TestCase):
             }
         ]
 
+    def test_group_add_option(self):
+
+        actual = config.load(build_config_details({
+            'version': '2',
+            'services': {
+                'web': {
+                    'image': 'alpine',
+                    'group_add': ["docker", 777]
+                }
+             }
+        }))
+
+        assert actual.services == [
+            {
+                'name': 'web',
+                'image': 'alpine',
+                'group_add': ["docker", 777]
+            }
+        ]
+
     def test_merge_service_dicts_from_files_with_extends_in_base(self):
         base = {
             'volumes': ['.:/app'],