From 6f2e409fb9bb4959310f26f2316bc4d4d228acc0 Mon Sep 17 00:00:00 2001
From: Thijs Walcarius <thijs.walcarius@ugent.be>
Date: Mon, 6 Apr 2020 16:26:16 +0200
Subject: [PATCH] Allow bypassing of spawn form by calling options in query
 arguments of /spawn

---
 jupyterhub/handlers/pages.py   | 26 ++++++++++++++++++++++++++
 jupyterhub/tests/test_pages.py | 22 ++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/jupyterhub/handlers/pages.py b/jupyterhub/handlers/pages.py
index 5cd1f4a7..6f1a43f2 100644
--- a/jupyterhub/handlers/pages.py
+++ b/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)
diff --git a/jupyterhub/tests/test_pages.py b/jupyterhub/tests/test_pages.py
index 20f3ea45..7ca4cb22 100644
--- a/jupyterhub/tests/test_pages.py
+++ b/jupyterhub/tests/test_pages.py
@@ -255,6 +255,28 @@ async def test_spawn_page_admin(app, admin_access):
         assert "Spawning server for {}".format(u.name) in r.text
 
 
+async def test_spawn_with_query_arguments(app):
+    with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
+        base_url = ujoin(public_host(app), app.hub.base_url)
+        cookies = await app.login_user('jones')
+        orm_u = orm.User.find(app.db, 'jones')
+        u = app.users[orm_u]
+        await u.stop()
+        next_url = ujoin(app.base_url, 'user/jones/tree')
+        r = await async_requests.get(
+            url_concat(
+                ujoin(base_url, 'spawn'), {'next': next_url, 'energy': '510keV'},
+            ),
+            cookies=cookies,
+        )
+        r.raise_for_status()
+        assert r.history
+        assert u.spawner.user_options == {
+            'energy': '510keV',
+            'notspecified': 5,
+        }
+
+
 async def test_spawn_form(app):
     with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
         base_url = ujoin(public_host(app), app.hub.base_url)