Adding parameter pulling functions

daphne/cli.py

@@ -6,6 +6,7 @@ from .access import AccessLogGenerator
 from .endpoints import build_endpoint_description_strings
 from .server import Server
 from .utils import import_by_path
+from argparse import ArgumentError, Namespace
 
 logger = logging.getLogger(__name__)
 
@@ -165,6 +166,40 @@ class CommandLineInterface(object):
         """
         cls().run(sys.argv[1:])
 
+    def _check_proxy_headers_passed(self, argument: str, args: Namespace):
+        """Raise if the `--proxy-headers` weren't specified."""
+        if args.proxy_headers:
+            return
+        raise ArgumentError(
+            argument=argument,
+            message="--proxy-headers has to be passed for this parameter.")
+
+    def _get_forwarded_host(self, args: Namespace):
+        """
+        Return the default host header from which the remote hostname/ip
+        will be extracted.
+        """
+        if args.proxy_headers_host:
+            self._check_proxy_headers_passed(
+                argument=self.arg_proxy_host, args=args)
+            return args.proxy_headers_host
+        if args.proxy_headers:
+            return "X-Forwarded-For"
+
+    def _get_forwarded_port(self, args: Namespace):
+        """
+        Return the default host header from which the remote hostname/ip
+        will be extracted.
+        """
+        if args.proxy_headers_port:
+            self._check_proxy_headers_passed(
+                argument=self.arg_proxy_port, args=args)
+            return args.proxy_headers_port
+        if args.proxy_headers:
+            return "X-Forwarded-Port"
+
+    def run(self, args):
+
     def run(self, args):
         """
         Pass in raw argument list and it will decode them
@@ -231,7 +266,7 @@ class CommandLineInterface(object):
             ws_protocols=args.ws_protocols,
             root_path=args.root_path,
             verbosity=args.verbosity,
-            proxy_forwarded_address_header="X-Forwarded-For" if args.proxy_headers else None,
+            proxy_forwarded_address_header=self._get_forwarded_host(args=args),
-            proxy_forwarded_port_header="X-Forwarded-Port" if args.proxy_headers else None,
+            proxy_forwarded_port_header=self._get_forwarded_port(args=args),
         )
         self.server.run()