Make volume host paths relative to file, merge volumes when extending

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>

tests/fixtures/volume-path/common/services.yml

@@ -0,0 +1,5 @@
+db:
+  image: busybox
+  volumes:
+    - ./foo:/foo
+    - ./bar:/bar

tests/fixtures/volume-path/docker-compose.yml

@@ -0,0 +1,6 @@
+db:
+  extends:
+    file: common/services.yml
+    service: db
+  volumes:
+    - ./bar:/bar

tests/integration/project_test.py

@@ -7,18 +7,19 @@ from .testcases import DockerClientTestCase
 
 class ProjectTest(DockerClientTestCase):
     def test_volumes_from_service(self):
+        service_dicts = config.from_dictionary({
+            'data': {
+                'image': 'busybox:latest',
+                'volumes': ['/var/data'],
+            },
+            'db': {
+                'image': 'busybox:latest',
+                'volumes_from': ['data'],
+            },
+        }, working_dir='.')
         project = Project.from_dicts(
             name='composetest',
-            service_dicts=config.from_dictionary({
-                'data': {
-                    'image': 'busybox:latest',
-                    'volumes': ['/var/data'],
-                },
-                'db': {
-                    'image': 'busybox:latest',
-                    'volumes_from': ['data'],
-                },
-            }),
+            service_dicts=service_dicts,
             client=self.client,
         )
         db = project.get_service('db')

tests/unit/config_test.py

@@ -133,7 +133,6 @@ class EnvTest(unittest.TestCase):
             {'FILE_DEF': 'F1', 'FILE_DEF_EMPTY': '', 'ENV_DEF': 'E3', 'NO_DEF': ''},
         )
 
-
 class ExtendsTest(unittest.TestCase):
     def test_extends(self):
         service_dicts = config.load('tests/fixtures/extends/docker-compose.yml')
@@ -241,3 +240,13 @@ class ExtendsTest(unittest.TestCase):
 
         with mock.patch.object(config, 'load_yaml', return_value=other_config):
             print load_config()
+
+    def test_volume_path(self):
+        dicts = config.load('tests/fixtures/volume-path/docker-compose.yml')
+
+        paths = [
+            '%s:/foo' % os.path.abspath('tests/fixtures/volume-path/common/foo'),
+            '%s:/bar' % os.path.abspath('tests/fixtures/volume-path/bar'),
+        ]
+
+        self.assertEqual(set(dicts[0]['volumes']), set(paths))