Merge pull request #199 from Tim-Erwin/improved_config

added methods to load config from a file

sanic/config.py

@@ -1,5 +1,11 @@
-class Config:
-    LOGO = """
+import os
+import types
+
+
+class Config(dict):
+    def __init__(self, defaults=None):
+        super().__init__(defaults or {})
+        self.LOGO = """
                  ▄▄▄▄▄
         ▀▀▀██████▄▄▄       _______________
       ▄▄▄▄▄  █████████▄  /                 \\
@@ -20,6 +26,65 @@ class Config:
 ▌     ▐                ▀▀▄▄▄▀
  ▀▀▄▄▀
 """
-    REQUEST_MAX_SIZE = 100000000  # 100 megababies
-    REQUEST_TIMEOUT = 60  # 60 seconds
-    ROUTER_CACHE_SIZE = 1024
+        self.REQUEST_MAX_SIZE = 100000000  # 100 megababies
+        self.REQUEST_TIMEOUT = 60  # 60 seconds
+
+    def __getattr__(self, attr):
+        try:
+            return self[attr]
+        except KeyError as ke:
+            raise AttributeError("Config has no '{}'".format(ke.args[0]))
+
+    def __setattr__(self, attr, value):
+        self[attr] = value
+
+    def from_envvar(self, variable_name):
+        """Loads a configuration from an environment variable pointing to
+        a configuration file.
+        :param variable_name: name of the environment variable
+        :return: bool. ``True`` if able to load config, ``False`` otherwise.
+        """
+        config_file = os.environ.get(variable_name)
+        if not config_file:
+            raise RuntimeError('The environment variable %r is not set and '
+                               'thus configuration could not be loaded.' %
+                               variable_name)
+        return self.from_pyfile(config_file)
+
+    def from_pyfile(self, filename):
+        """Updates the values in the config from a Python file. Only the uppercase
+        variables in that module are stored in the config.
+        :param filename: an absolute path to the config file
+        """
+        module = types.ModuleType('config')
+        module.__file__ = filename
+        try:
+            with open(filename) as config_file:
+                exec(compile(config_file.read(), filename, 'exec'),
+                     module.__dict__)
+        except IOError as e:
+            e.strerror = 'Unable to load configuration file (%s)' % e.strerror
+            raise
+        self.from_object(module)
+        return True
+
+    def from_object(self, obj):
+        """Updates the values from the given object.
+        Objects are usually either modules or classes.
+
+        Just the uppercase variables in that object are stored in the config.
+        Example usage::
+
+            from yourapplication import default_config
+            app.config.from_object(default_config)
+
+        You should not use this function to load the actual configuration but
+        rather configuration defaults. The actual config should be loaded
+        with :meth:`from_pyfile` and ideally from a location not within the
+        package because the package might be installed system wide.
+
+        :param obj: an object holding the configuration
+        """
+        for key in dir(obj):
+            if key.isupper():
+                self[key] = getattr(obj, key)

sanic/router.py

@@ -1,7 +1,6 @@
 import re
 from collections import defaultdict, namedtuple
 from functools import lru_cache
-from .config import Config
 from .exceptions import NotFound, InvalidUsage
 from .views import CompositionView
 
@@ -15,6 +14,8 @@ REGEX_TYPES = {
     'alpha': (str, r'[A-Za-z]+'),
 }
 
+ROUTER_CACHE_SIZE = 1024
+
 
 def url_hash(url):
     return url.count('/')
@@ -198,7 +199,7 @@ class Router:
             return self._get(request.url, request.method,
                              request.headers.get("Host", ''))
 
-    @lru_cache(maxsize=Config.ROUTER_CACHE_SIZE)
+    @lru_cache(maxsize=ROUTER_CACHE_SIZE)
     def _get(self, url, method, host):
         """
         Gets a request handler based on the URL of the request, or raises an