Merge pull request AppScale#3183 from whoarethebritons/task-redirect-…

…scheme

Tasks should use http to avoid scheme redirects since they use HAProxy

AppServer/google/appengine/tools/devappserver2/module.py

@@ -581,7 +581,7 @@ def _handle_request_impl(self, environ, start_response, inst=None,
     try:
       environ['SERVER_PORT'] = environ['HTTP_HOST'].split(':')[1]
     except IndexError:
-      scheme = environ['HTTP_X_FORWARDED_PROTO']
+      scheme = environ.get('HTTP_X_FORWARDED_PROTO', 'http')
       if scheme == 'http':
         environ['SERVER_PORT'] = 80
       else:

AppTaskQueue/appscale/taskqueue/push_worker.py

@@ -154,35 +154,30 @@ def execute_task(task, headers, args):
         update_task(task_name, TASK_STATES.FAILED)
         return
 
-      # Targets do not get X-Forwarded-Proto from nginx, they use haproxy port.
-      headers['X-Forwarded-Proto'] = url.scheme
-      if url.scheme == 'http':
-        connection = httplib.HTTPConnection(remote_host, url.port)
-      elif url.scheme == 'https':
-        connection = httplib.HTTPSConnection(remote_host, url.port)
-      else:
-        logger.error("Task %s tried to use url scheme %s, "
-                     "which is not supported." % (
-                     args['task_name'], url.scheme))
-
-      skip_host = False
-      if b'host' in headers or b'Host' in headers:
-        skip_host = True
+      # Tasks should use HTTP to bypass scheme redirects since they use HAProxy.
+      connection = httplib.HTTPConnection(remote_host, url.port)
 
       skip_accept_encoding = False
       if 'accept-encoding' in headers or 'Accept-Encoding' in headers:
         skip_accept_encoding = True
 
       connection.putrequest(method,
                             urlpath,
-                            skip_host=skip_host,
                             skip_accept_encoding=skip_accept_encoding)
 
       # Update the task headers
       headers['X-AppEngine-TaskRetryCount'] = str(task.request.retries)
       headers['X-AppEngine-TaskExecutionCount'] = str(task.request.retries)
 
       for header in headers:
+        # Avoid changing the host header from the HAProxy location. Though GAE
+        # supports host-based routing, we need to make some additional changes
+        # before we can behave in a similar manner. Using the HAProxy location
+        # for the host header allows the dispatcher to try extracting a port,
+        # which it uses to set environment variables for the request.
+        if header == b'Host':
+          continue
+
         connection.putheader(header, headers[header])
 
       if 'content-type' not in headers or 'Content-Type' not in headers: