Add support for docker run --tmpfs flag.

Signed-off-by: Philip Walls <pawalls@rabidgeek.com>

tests/integration/service_test.py

@@ -875,6 +875,11 @@ class ServiceTest(DockerClientTestCase):
         container = create_and_start_container(service)
         self.assertEqual(container.get('HostConfig.DnsSearch'), ['dc1.example.com', 'dc2.example.com'])
 
+    def test_tmpfs(self):
+        service = self.create_service('web', tmpfs=['/run'])
+        container = create_and_start_container(service)
+        self.assertEqual(container.get('HostConfig.Tmpfs'), {'/run': ''})
+
     def test_working_dir_param(self):
         service = self.create_service('container', working_dir='/working/dir/sample')
         container = service.create_container()

tests/unit/config/config_test.py

@@ -1194,6 +1194,21 @@ class ConfigTest(unittest.TestCase):
             }
         ]
 
+    def test_tmpfs_option(self):
+        actual = config.load(build_config_details({
+            'web': {
+                'image': 'alpine',
+                'tmpfs': '/run',
+            }
+        }))
+        assert actual.services == [
+            {
+                'name': 'web',
+                'image': 'alpine',
+                'tmpfs': ['/run'],
+            }
+        ]
+
     def test_merge_service_dicts_from_files_with_extends_in_base(self):
         base = {
             'volumes': ['.:/app'],