add remote_addr property for proxy fix

sanic/request.py

@@ -45,7 +45,7 @@ class Request(dict):
     __slots__ = (
         'app', 'headers', 'version', 'method', '_cookies', 'transport',
         'body', 'parsed_json', 'parsed_args', 'parsed_form', 'parsed_files',
-        '_ip', '_parsed_url', 'uri_template', 'stream'
+        '_ip', '_parsed_url', 'uri_template', 'stream', '_remote_addr'
     )
 
     def __init__(self, url_bytes, headers, version, method, transport):
@@ -142,7 +142,7 @@ class Request(dict):
     @property
     def cookies(self):
         if self._cookies is None:
-            cookie = self.headers.get('Cookie') or self.headers.get('cookie')
+            cookie = self.headers.get('Cookie')
             if cookie is not None:
                 cookies = SimpleCookie()
                 cookies.load(cookie)
@@ -159,6 +159,23 @@ class Request(dict):
                         (None, None))
         return self._ip
 
+    @property
+    def remote_addr(self):
+        """Attempt to return the original client ip based on X-Forwarded-For.
+
+        :return: original client ip.
+        """
+        if not hasattr(self, '_remote_addr'):
+            forwarded_for = self.headers.get('X-Forwarded-For', '').split(',')
+            remote_addrs = [
+                addr for addr in [addr.strip() for addr in forwarded_for] if addr
+            ]
+            if len(remote_addrs) > 0:
+                self._remote_addr = remote_addrs[0]
+            else:
+                self._remote_addr = ''
+        return self._remote_addr
+
     @property
     def scheme(self):
         if self.app.websocket_enabled \