Give eventlet access to the socket when running under gunicorn

engineio/middleware.py

@@ -26,6 +26,21 @@ def __init__(self, engineio_app, wsgi_app=None, engineio_path='engine.io'):
         self.engineio_path = engineio_path
 
     def __call__(self, environ, start_response):
+        if 'gunicorn.socket' in environ:
+            # gunicorn saves the socket under environ['gunicorn.socket'], while
+            # eventlet saves it under environ['eventlet.input']. Eventlet also
+            # stores the socket inside a wrapper class, while gunicon writes it
+            # directly into the environment. To give eventlet's WebSocket
+            # module access to this socket when running under gunicorn, here we
+            # copy the socket to the eventlet format.
+            class Input(object):
+                def __init__(self, socket):
+                    self.socket = socket
+
+                def get_socket(self):
+                    return self.socket
+
+            environ['eventlet.input'] = Input(environ['gunicorn.socket'])
         path = environ['PATH_INFO']
         if path is not None and \
                 path.startswith('/{0}/'.format(self.engineio_path)):

tests/test_middleware.py

@@ -40,3 +40,13 @@ def test_404(self):
         self.assertEqual(r, ['Not Found'])
         start_response.assert_called_once_with(
             "404 Not Found", [('Content-type', 'text/plain')])
+
+    def test_gunicorn_socket(self):
+        mock_wsgi_app = None
+        mock_eio_app = mock.Mock()
+        m = middleware.Middleware(mock_eio_app, mock_wsgi_app)
+        environ = {'gunicorn.socket': 123, 'PATH_INFO': '/foo/bar'}
+        start_response = mock.MagicMock()
+        m(environ, start_response)
+        self.assertIn('eventlet.input', environ)
+        self.assertEqual(environ['eventlet.input'].get_socket(), 123)