Allow to load setting from a non python path

Author: yohanboniface

manage.py

@@ -5,7 +5,7 @@
 if __name__ == "__main__":
     os.environ.setdefault(
         "DJANGO_SETTINGS_MODULE",
-        "umap.settings.local"
+        "umap.settings"
     )
 
     from django.core.management import execute_from_command_line

umap/settings/__init__.py

@@ -0,0 +1,32 @@
+import imp
+import os
+import sys
+
+from django.utils.termcolors import colorize
+
+from .base import *  # NOQA, default values
+
+# Allow to override setting from any file, may be out of the PYTHONPATH,
+# to make it easier for non python people.
+path = os.environ.get('UMAP_SETTINGS')
+if path:
+    d = imp.new_module('config')
+    d.__file__ = path
+    try:
+        with open(path) as config_file:
+            exec(compile(config_file.read(), path, 'exec'), d.__dict__)
+    except IOError as e:
+        msg = 'Unable to import {} from UMAP_SETTINGS'.format(path)
+        print(colorize(msg, fg='red'))
+        sys.exit(e)
+    else:
+        print('Loaded local config from', path)
+        for key in dir(d):
+            if key.isupper():
+                globals()[key] = getattr(d, key)
+else:
+    # Retrocompat
+    try:
+        from .local import *  # NOQA
+    except ImportError:
+        pass