Require volumes_from a container to be explicit in V2 config.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

compose/config/config.py

@@ -292,7 +292,7 @@ def load_volumes(config_files):
 
 
 def load_services(working_dir, filename, service_configs, version):
-    def build_service(service_name, service_dict):
+    def build_service(service_name, service_dict, service_names):
         service_config = ServiceConfig.with_abs_paths(
             working_dir,
             filename,
@@ -305,13 +305,17 @@ def load_services(working_dir, filename, service_configs, version):
         validate_against_service_schema(service_dict, service_config.name, version)
         validate_paths(service_dict)
 
-        service_dict = finalize_service(service_config._replace(config=service_dict))
+        service_dict = finalize_service(
+            service_config._replace(config=service_dict),
+            service_names,
+            version)
         service_dict['name'] = service_config.name
         return service_dict
 
     def build_services(service_config):
+        service_names = service_config.keys()
         return sort_service_dicts([
-            build_service(name, service_dict)
+            build_service(name, service_dict, service_names)
             for name, service_dict in service_config.items()
         ])
 
@@ -504,7 +508,7 @@ def process_service(service_config):
     return service_dict
 
 
-def finalize_service(service_config):
+def finalize_service(service_config, service_names, version):
     service_dict = dict(service_config.config)
 
     if 'environment' in service_dict or 'env_file' in service_dict:
@@ -513,7 +517,9 @@ def finalize_service(service_config):
 
     if 'volumes_from' in service_dict:
         service_dict['volumes_from'] = [
-            VolumeFromSpec.parse(vf) for vf in service_dict['volumes_from']]
+            VolumeFromSpec.parse(vf, service_names, version)
+            for vf in service_dict['volumes_from']
+        ]
 
     if 'volumes' in service_dict:
         service_dict['volumes'] = [

compose/config/types.py

@@ -11,10 +11,16 @@ from compose.config.errors import ConfigurationError
 from compose.const import IS_WINDOWS_PLATFORM
 
 
-class VolumeFromSpec(namedtuple('_VolumeFromSpec', 'source mode')):
+class VolumeFromSpec(namedtuple('_VolumeFromSpec', 'source mode type')):
+
+    # TODO: drop service_names arg when v1 is removed
+    @classmethod
+    def parse(cls, volume_from_config, service_names, version):
+        func = cls.parse_v1 if version == 1 else cls.parse_v2
+        return func(service_names, volume_from_config)
 
     @classmethod
-    def parse(cls, volume_from_config):
+    def parse_v1(cls, service_names, volume_from_config):
         parts = volume_from_config.split(':')
         if len(parts) > 2:
             raise ConfigurationError(
@@ -27,7 +33,39 @@ class VolumeFromSpec(namedtuple('_VolumeFromSpec', 'source mode')):
         else:
             source, mode = parts
 
-        return cls(source, mode)
+        type = 'service' if source in service_names else 'container'
+        return cls(source, mode, type)
+
+    @classmethod
+    def parse_v2(cls, service_names, volume_from_config):
+        parts = volume_from_config.split(':')
+        if len(parts) > 3:
+            raise ConfigurationError(
+                "volume_from {} has incorrect format, should be one of "
+                "'<service name>[:<mode>]' or "
+                "'container:<container name>[:<mode>]'".format(volume_from_config))
+
+        if len(parts) == 1:
+            source = parts[0]
+            return cls(source, 'rw', 'service')
+
+        if len(parts) == 2:
+            if parts[0] == 'container':
+                type, source = parts
+                return cls(source, 'rw', type)
+
+            source, mode = parts
+            return cls(source, mode, 'service')
+
+        if len(parts) == 3:
+            type, source, mode = parts
+            if type not in ('service', 'container'):
+                raise ConfigurationError(
+                    "Unknown volumes_from type '{}' in '{}'".format(
+                        type,
+                        volume_from_config))
+
+        return cls(source, mode, type)
 
 
 def parse_restart_spec(restart_config):

compose/project.py

@@ -60,7 +60,7 @@ class Project(object):
 
         for service_dict in config_data.services:
             links = project.get_links(service_dict)
-            volumes_from = project.get_volumes_from(service_dict)
+            volumes_from = get_volumes_from(project, service_dict)
             net = project.get_net(service_dict)
 
             project.services.append(
@@ -162,28 +162,6 @@ class Project(object):
             del service_dict['links']
         return links
 
-    def get_volumes_from(self, service_dict):
-        volumes_from = []
-        if 'volumes_from' in service_dict:
-            for volume_from_spec in service_dict.get('volumes_from', []):
-                # Get service
-                try:
-                    service = self.get_service(volume_from_spec.source)
-                    volume_from_spec = volume_from_spec._replace(source=service)
-                except NoSuchService:
-                    try:
-                        container = Container.from_id(self.client, volume_from_spec.source)
-                        volume_from_spec = volume_from_spec._replace(source=container)
-                    except APIError:
-                        raise ConfigurationError(
-                            'Service "%s" mounts volumes from "%s", which is '
-                            'not the name of a service or container.' % (
-                                service_dict['name'],
-                                volume_from_spec.source))
-                volumes_from.append(volume_from_spec)
-            del service_dict['volumes_from']
-        return volumes_from
-
     def get_net(self, service_dict):
         net = service_dict.pop('net', None)
         if not net:
@@ -465,6 +443,34 @@ def remove_links(service_dicts):
         del s['links']
 
 
+def get_volumes_from(project, service_dict):
+    volumes_from = service_dict.pop('volumes_from', None)
+    if not volumes_from:
+        return []
+
+    def build_volume_from(spec):
+        if spec.type == 'service':
+            try:
+                return spec._replace(source=project.get_service(spec.source))
+            except NoSuchService:
+                pass
+
+        if spec.type == 'container':
+            try:
+                container = Container.from_id(project.client, spec.source)
+                return spec._replace(source=container)
+            except APIError:
+                pass
+
+        raise ConfigurationError(
+            "Service \"{}\" mounts volumes from \"{}\", which is not the name "
+            "of a service or container.".format(
+                service_dict['name'],
+                spec.source))
+
+    return [build_volume_from(vf) for vf in volumes_from]
+
+
 class NoSuchService(Exception):
     def __init__(self, name):
         self.name = name