Move parsing of volumes_from to the last step of config parsing.

Includes creating a new compose.config.types module for all the domain objects.

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

compose/config/config.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import
+
 import codecs
 import logging
 import operator
@@ -12,6 +14,7 @@ from .errors import CircularReference
 from .errors import ComposeFileNotFound
 from .errors import ConfigurationError
 from .interpolation import interpolate_environment_variables
+from .types import VolumeFromSpec
 from .validation import validate_against_fields_schema
 from .validation import validate_against_service_schema
 from .validation import validate_extends_file_path
@@ -198,8 +201,12 @@ def load(config_details):
             service_dict)
         resolver = ServiceExtendsResolver(service_config)
         service_dict = process_service(resolver.run())
+
+        # TODO: move to validate_service()
         validate_against_service_schema(service_dict, service_config.name)
         validate_paths(service_dict)
+
+        service_dict = finalize_service(service_config._replace(config=service_dict))
         service_dict['name'] = service_config.name
         return service_dict
 
@@ -353,6 +360,7 @@ def validate_ulimits(ulimit_config):
                     "than 'hard' value".format(ulimit_config))
 
 
+# TODO: rename to normalize_service
 def process_service(service_config):
     working_dir = service_config.working_dir
     service_dict = dict(service_config.config)
@@ -370,12 +378,23 @@ def process_service(service_config):
     if 'labels' in service_dict:
         service_dict['labels'] = parse_labels(service_dict['labels'])
 
+    # TODO: move to a validate_service()
     if 'ulimits' in service_dict:
         validate_ulimits(service_dict['ulimits'])
 
     return service_dict
 
 
+def finalize_service(service_config):
+    service_dict = dict(service_config.config)
+
+    if 'volumes_from' in service_dict:
+        service_dict['volumes_from'] = [
+            VolumeFromSpec.parse(vf) for vf in service_dict['volumes_from']]
+
+    return service_dict
+
+
 def merge_service_dicts_from_files(base, override):
     """When merging services from multiple files we need to merge the `extends`
     field. This is not handled by `merge_service_dicts()` which is used to

compose/config/types.py

@@ -0,0 +1,28 @@
+"""
+Types for objects parsed from the configuration.
+"""
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+from collections import namedtuple
+
+from compose.config.errors import ConfigurationError
+
+
+class VolumeFromSpec(namedtuple('_VolumeFromSpec', 'source mode')):
+
+    @classmethod
+    def parse(cls, volume_from_config):
+        parts = volume_from_config.split(':')
+        if len(parts) > 2:
+            raise ConfigurationError(
+                "volume_from {} has incorrect format, should be "
+                "service[:mode]".format(volume_from_config))
+
+        if len(parts) == 1:
+            source = parts[0]
+            mode = 'rw'
+        else:
+            source, mode = parts
+
+        return cls(source, mode)

compose/project.py

@@ -19,10 +19,8 @@ from .legacy import check_for_legacy_containers
 from .service import ContainerNet
 from .service import ConvergenceStrategy
 from .service import Net
-from .service import parse_volume_from_spec
 from .service import Service
 from .service import ServiceNet
-from .service import VolumeFromSpec
 
 
 log = logging.getLogger(__name__)
@@ -38,10 +36,7 @@ def sort_service_dicts(services):
         return [link.split(':')[0] for link in links]
 
     def get_service_names_from_volumes_from(volumes_from):
-        return [
-            parse_volume_from_spec(volume_from).source
-            for volume_from in volumes_from
-        ]
+        return [volume_from.source for volume_from in volumes_from]
 
     def get_service_dependents(service_dict, services):
         name = service_dict['name']
@@ -192,16 +187,15 @@ class Project(object):
     def get_volumes_from(self, service_dict):
         volumes_from = []
         if 'volumes_from' in service_dict:
-            for volume_from_config in service_dict.get('volumes_from', []):
-                volume_from_spec = parse_volume_from_spec(volume_from_config)
+            for volume_from_spec in service_dict.get('volumes_from', []):
                 # Get service
                 try:
-                    service_name = self.get_service(volume_from_spec.source)
-                    volume_from_spec = VolumeFromSpec(service_name, volume_from_spec.mode)
+                    service = self.get_service(volume_from_spec.source)
+                    volume_from_spec = volume_from_spec._replace(source=service)
                 except NoSuchService:
                     try:
-                        container_name = Container.from_id(self.client, volume_from_spec.source)
-                        volume_from_spec = VolumeFromSpec(container_name, volume_from_spec.mode)
+                        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 '

compose/service.py

@@ -70,6 +70,7 @@ class BuildError(Exception):
         self.reason = reason
 
 
+# TODO: remove
 class ConfigError(ValueError):
     pass
 
@@ -86,9 +87,6 @@ class NoSuchImageError(Exception):
 VolumeSpec = namedtuple('VolumeSpec', 'external internal mode')
 
 
-VolumeFromSpec = namedtuple('VolumeFromSpec', 'source mode')
-
-
 ServiceName = namedtuple('ServiceName', 'project service number')
 
 
@@ -1029,21 +1027,6 @@ def build_volume_from(volume_from_spec):
         return ["{}:{}".format(volume_from_spec.source.id, volume_from_spec.mode)]
 
 
-def parse_volume_from_spec(volume_from_config):
-    parts = volume_from_config.split(':')
-    if len(parts) > 2:
-        raise ConfigError("Volume %s has incorrect format, should be "
-                          "external:internal[:mode]" % volume_from_config)
-
-    if len(parts) == 1:
-        source = parts[0]
-        mode = 'rw'
-    else:
-        source, mode = parts
-
-    return VolumeFromSpec(source, mode)
-
-
 # Labels