Export the Config class so modules can use it instead of reimplementing it.

ppp_core/__init__.py

 """Core/router of the Projet Pensées Profondes."""
 
 from .http import app, HttpRequestHandler
+from .config import Config

ppp_core/config.py

@@ -19,8 +19,12 @@ class Module(namedtuple('_Module', 'name url coefficient')):
 
 
 class Config:
-    __slots__ = ('debug', 'modules')
+    __slots__ = ('debug',)
     def __init__(self, data=None):
+        if not hasattr(self, 'config_path_variable') or \
+                not hasattr(self, 'parse_config'):
+            raise NotImplementedError('Config class does not implement all '
+                                      'required attributes.')
         self.debug = True
         if not data:
             try:
@@ -28,16 +32,23 @@ class Config:
                     data = json.load(fd)
             except ValueError as exc:
                 raise InvalidConfig(*exc.args)
-        self.modules = self._parse_modules(data.get('modules', {}))
-        self.debug = data.get('debug', False)
+        self.parse_config(data)
 
-    @staticmethod
-    def get_config_path():
-        path = os.environ.get('PPP_CORE_CONFIG', '')
+    @classmethod
+    def get_config_path(cls):
+        path = os.environ.get(cls.config_path_variable, '')
         if not path:
             raise InvalidConfig('Could not find config file, please set '
-                                'environment variable $PPP_CORE_CONFIG.')
+                                'environment variable $%s.' %
+                                cls.config_path_variable)
         return path
+class CoreConfig(Config):
+    __slots__ = ('modules')
+    config_path_variable = 'PPP_CORE_CONFIG'
+
+    def parse_config(self, data):
+        self.modules = self._parse_modules(data.get('modules', {}))
+        self.debug = data.get('debug', False)
 
     def _parse_modules(self, data):
         modules = []
@@ -49,3 +60,4 @@ class Config:
                         config['name'])
             modules.append(Module(**config))
         return modules
+

ppp_core/router.py

@@ -8,7 +8,7 @@ import itertools
 import functools
 from ppp_datamodel import AbstractNode
 from ppp_datamodel.communication import Request, Response
-from .config import Config
+from .config import CoreConfig
 from .exceptions import ClientError, BadGateway
 
 s = lambda x:x if isinstance(x, str) else x.decode()
@@ -21,7 +21,7 @@ class Router:
         self.tree = request.tree
         self.measures = request.measures
         self.trace = request.trace
-        self.config = Config()
+        self.config = CoreConfig()
 
     def answer(self):
         # First make all requests so modules can prepare their answer