Allow for other hosts than localhost to be proxied.

Author: ian-r-rose

jupyter_server_proxy/handlers.py

@@ -28,14 +28,17 @@ def get(self, *args):
         dest = src._replace(path=src.path + '/')
         self.redirect(urlunparse(dest))
 
-class LocalProxyHandler(WebSocketHandlerMixin, IPythonHandler):
-
+class ProxyHandler(WebSocketHandlerMixin, IPythonHandler):
+    """
+    A tornado request handler that proxies HTTP and websockets from
+    a given host/port combination.
+    """
     def __init__(self, *args, **kwargs):
         self.proxy_base = ''
         self.absolute_url = kwargs.pop('absolute_url', False)
         super().__init__(*args, **kwargs)
 
-    async def open(self, port, proxied_path=''):
+    async def open(self, host, port, proxied_path=''):
         """
         Called when a client opens a websocket connection.
 
@@ -45,7 +48,7 @@ async def open(self, port, proxied_path=''):
         if not proxied_path.startswith('/'):
             proxied_path = '/' + proxied_path
 
-        client_uri = self.get_client_uri('ws', port, proxied_path)
+        client_uri = self.get_client_uri('ws', host, port, proxied_path)
         headers = self.request.headers
 
         def message_cb(message):
@@ -141,7 +144,7 @@ def _get_context_path(self, port):
         else:
             return url_path_join(self.base_url, 'proxy', str(port))
 
-    def get_client_uri(self, protocol, port, proxied_path):
+    def get_client_uri(self, protocol, host, port, proxied_path):
         context_path = self._get_context_path(port)
         if self.absolute_url:
             client_path = url_path_join(context_path, proxied_path)
@@ -150,7 +153,7 @@ def get_client_uri(self, protocol, port, proxied_path):
 
         client_uri = '{protocol}://{host}:{port}{path}'.format(
             protocol=protocol,
-            host='localhost',
+            host=host,
             port=port,
             path=client_path
         )
@@ -159,11 +162,11 @@ def get_client_uri(self, protocol, port, proxied_path):
 
         return client_uri
 
-    def _build_proxy_request(self, port, proxied_path, body):
+    def _build_proxy_request(self, host, port, proxied_path, body):
 
         headers = self.proxy_request_headers()
 
-        client_uri = self.get_client_uri('http', port, proxied_path)
+        client_uri = self.get_client_uri('http', host, port, proxied_path)
         # Some applications check X-Forwarded-Context and X-ProxyContextPath
         # headers to see if and where they are being proxied from.
         if not self.absolute_url:
@@ -177,7 +180,7 @@ def _build_proxy_request(self, port, proxied_path, body):
         return req
 
     @web.authenticated
-    async def proxy(self, port, proxied_path):
+    async def proxy(self, host, port, proxied_path):
         '''
         This serverextension handles:
             {base_url}/proxy/{port([0-9]+)}/{proxied_path}
@@ -205,7 +208,7 @@ async def proxy(self, port, proxied_path):
 
         client = httpclient.AsyncHTTPClient()
 
-        req = self._build_proxy_request(port, proxied_path, body)
+        req = self._build_proxy_request(host, port, proxied_path, body)
         response = await client.fetch(req, raise_error=False)
         # record activity at start and end of requests
         self._record_activity()
@@ -242,27 +245,27 @@ def proxy_request_options(self):
     # Support all the methods that torando does by default except for GET which
     # is passed to WebSocketHandlerMixin and then to WebSocketHandler.
 
-    async def http_get(self, port, proxy_path=''):
+    async def http_get(self, host, port, proxy_path=''):
         '''Our non-websocket GET.'''
-        return await self.proxy(port, proxy_path)
+        return await self.proxy(host, port, proxy_path)
 
-    def post(self, port, proxy_path=''):
-        return self.proxy(port, proxy_path)
+    def post(self, host, port, proxy_path=''):
+        return self.proxy(host, port, proxy_path)
 
     def put(self, port, proxy_path=''):
-        return self.proxy(port, proxy_path)
+        return self.proxy(host, port, proxy_path)
 
-    def delete(self, port, proxy_path=''):
-        return self.proxy(port, proxy_path)
+    def delete(self, host, port, proxy_path=''):
+        return self.proxy(host, port, proxy_path)
 
-    def head(self, port, proxy_path=''):
-        return self.proxy(port, proxy_path)
+    def head(self, host, port, proxy_path=''):
+        return self.proxy(host, port, proxy_path)
 
-    def patch(self, port, proxy_path=''):
-        return self.proxy(port, proxy_path)
+    def patch(self, host, port, proxy_path=''):
+        return self.proxy(host, port, proxy_path)
 
-    def options(self, port, proxy_path=''):
-        return self.proxy(port, proxy_path)
+    def options(self, host, port, proxy_path=''):
+        return self.proxy(host, port, proxy_path)
 
     def check_xsrf_cookie(self):
         '''
@@ -280,6 +283,40 @@ def select_subprotocol(self, subprotocols):
         return super().select_subprotocol(subprotocols)
 
 
+class LocalProxyHandler(ProxyHandler):
+    """
+    A tornado request handler that proxies HTTP and websockets
+    from a port on the local system. Same as the above ProxyHandler,
+    but specific to 'localhost'.
+    """
+    async def http_get(self, port, proxied_path):
+        return await self.proxy(port, proxied_path)
+
+    async def open(self, port, proxied_path):
+        return await super().open('localhost', port, proxied_path)
+
+    def post(self, port, proxied_path):
+        return self.proxy(port, proxied_path)
+
+    def put(self, port, proxied_path):
+        return self.proxy(port, proxied_path)
+
+    def delete(self, port, proxied_path):
+        return self.proxy(port, proxied_path)
+
+    def head(self, port, proxied_path):
+        return self.proxy(port, proxied_path)
+
+    def patch(self, port, proxied_path):
+        return self.proxy(port, proxied_path)
+
+    def options(self, port, proxied_path):
+        return self.proxy(port, proxied_path)
+
+    def proxy(self, port, proxied_path):
+        return super().proxy('localhost', port, proxied_path)
+
+
 # FIXME: Move this to its own file. Too many packages now import this from nbrserverproxy.handlers
 class SuperviseAndProxyHandler(LocalProxyHandler):
     '''Manage a given process and requests to it '''