Add api_token from environment, if it's present.

jupyterlab/labhubapp.py

@@ -1,3 +1,4 @@
+import os
 from .labapp import LabApp
 
 try:
@@ -7,6 +8,7 @@ except ImportError:
     raise ImportError('You must have jupyterhub installed for this to work.')
 else:
     class SingleUserLabApp(SingleUserNotebookApp, LabApp):
+
         def init_webapp(self, *args, **kwargs):
             super().init_webapp(*args, **kwargs)
             settings = self.web_app.settings
@@ -15,6 +17,15 @@ else:
             settings['page_config_data']['hub_prefix'] = self.hub_prefix
             settings['page_config_data']['hub_host'] = self.hub_host
             settings['page_config_data']['hub_user'] = self.user
+            api_token = os.getenv('JUPYTERHUB_API_TOKEN')
+            if not api_token:
+                api_token = ''
+            if not self.token:
+                try:
+                    self.token = api_token
+                except AttributeError:
+                    self.log.error("Can't set self.token")
+            settings['page_config_data']['token'] = api_token
 
 
 def main(argv=None):