Allow bypassing of spawn form by calling options in query arguments of /spawn

jupyterhub/handlers/pages.py

@@ -173,6 +173,32 @@ class SpawnHandler(BaseHandler):
         auth_state = await user.get_auth_state()
         await spawner.run_auth_state_hook(auth_state)
 
+        # Try to start server directly when query arguments are passed.
+        form_options = {}
+        for key, byte_list in self.request.query_arguments.items():
+            form_options[key] = [bs.decode('utf8') for bs in byte_list]
+
+        # 'next' is reserved argument for redirect after spawn
+        form_options.pop('next', None)
+
+        if len(form_options) > 0:
+            try:
+                self.log.debug(
+                    "Triggering spawn with supplied query arguments for %s",
+                    spawner._log_name,
+                )
+                options = await maybe_future(spawner.options_from_form(form_options))
+                pending_url = self._get_pending_url(user, server_name)
+                return await self._wrap_spawn_single_user(
+                    user, server_name, spawner, pending_url, options
+                )
+            except Exception as e:
+                self.log.error(
+                    "Failed to spawn single-user server with query arguments",
+                    exc_info=True,
+                )
+                # fallback to behavior without failing query arguments
+
         spawner_options_form = await spawner.get_options_form()
         if spawner_options_form:
             self.log.debug("Serving options form for %s", spawner._log_name)