Merge pull request jupyter-server#380 from afshin/autoreload

Add --autoreload flag

Author: kevin-bates

jupyter_server/serverapp.py

@@ -530,6 +530,16 @@ def start(self):
     },
     _("Set debug level for the extension and underlying server applications.")
 )
+flags['autoreload'] = (
+    {'ServerApp': {'autoreload': True}},
+    """Autoreload the webapp
+    Enable reloading of the tornado webapp and all imported Python packages
+    when any changes are made to any Python src files in server or
+    extensions.
+    """
+)
+
+
 # Add notebook manager flags
 flags.update(boolean_flag('script', 'FileContentsManager.save_script',
                'DEPRECATED, IGNORED',
@@ -644,6 +654,10 @@ def _default_log_format(self):
         help=_("Whether to allow the user to run the server as root.")
     )
 
+    autoreload = Bool(False, config=True,
+        help= ("Reload the webapp when changes are made to any Python src files.")
+    )
+
     default_url = Unicode('/', config=True,
         help=_("The default URL to redirect to from `/`")
     )
@@ -1385,6 +1399,7 @@ def init_webapp(self):
         if self.allow_origin_pat:
             self.tornado_settings['allow_origin_pat'] = re.compile(self.allow_origin_pat)
         self.tornado_settings['allow_credentials'] = self.allow_credentials
+        self.tornado_settings['autoreload'] = self.autoreload
         self.tornado_settings['cookie_options'] = self.cookie_options
         self.tornado_settings['get_secure_cookie_kwargs'] = self.get_secure_cookie_kwargs
         self.tornado_settings['token'] = self.token