Merge pull request #2712 from jzvelc/fix_v2_service_extend

Fix `extends` when using v2 config format

compose/config/config.py

@@ -136,6 +136,9 @@ class ConfigFile(namedtuple('_ConfigFile', 'filename config')):
             return 1
         return version
 
+    def get_service(self, name):
+        return self.get_service_dicts()[name]
+
     def get_service_dicts(self):
         return self.config if self.version == 1 else self.config.get('services', {})
 
@@ -354,19 +357,19 @@ def process_config_file(config_file, service_name=None):
 
     if config_file.version == 2:
         processed_config = dict(config_file.config)
-        processed_config['services'] = interpolated_config
+        processed_config['services'] = services = interpolated_config
         processed_config['volumes'] = interpolate_environment_variables(
             config_file.get_volumes(), 'volume')
         processed_config['networks'] = interpolate_environment_variables(
             config_file.get_networks(), 'network')
 
     if config_file.version == 1:
-        processed_config = interpolated_config
+        processed_config = services = interpolated_config
 
     config_file = config_file._replace(config=processed_config)
     validate_against_fields_schema(config_file)
 
-    if service_name and service_name not in processed_config:
+    if service_name and service_name not in services:
         raise ConfigurationError(
             "Cannot extend service '{}' in {}: Service not found".format(
                 service_name, config_file.filename))
@@ -411,7 +414,8 @@ class ServiceExtendsResolver(object):
         extended_file = process_config_file(
             extends_file,
             service_name=service_name)
-        service_config = extended_file.config[service_name]
+        service_config = extended_file.get_service(service_name)
+
         return config_path, service_config, service_name
 
     def resolve_extends(self, extended_config_path, service_dict, service_name):

tests/unit/config/config_test.py

@@ -1937,6 +1937,30 @@ class ExtendsTest(unittest.TestCase):
             load_from_filename(str(tmpdir.join('docker-compose.yml')))
         assert 'Version mismatch' in exc.exconly()
 
+    def test_extends_with_defined_version_passes(self):
+        tmpdir = py.test.ensuretemp('test_extends_with_defined_version')
+        self.addCleanup(tmpdir.remove)
+        tmpdir.join('docker-compose.yml').write("""
+            version: 2
+            services:
+              web:
+                extends:
+                  file: base.yml
+                  service: base
+                image: busybox
+        """)
+        tmpdir.join('base.yml').write("""
+            version: 2
+            services:
+                base:
+                  volumes: ['/foo']
+                  ports: ['3000:3000']
+                  command: top
+        """)
+
+        service = load_from_filename(str(tmpdir.join('docker-compose.yml')))
+        self.assertEquals(service[0]['command'], "top")
+
 
 @pytest.mark.xfail(IS_WINDOWS_PLATFORM, reason='paths use slash')
 class ExpandPathTest(unittest.TestCase):