show who you're spawning for if it's not yourself

on the spawn page

jupyterhub/handlers/pages.py

@@ -88,11 +88,11 @@ class SpawnHandler(BaseHandler):
     Only enabled when Spawner.options_form is defined.
     """
     @gen.coroutine
-    def _render_form(self, message=''):
+    def _render_form(self, message='', for_user=None):
         user = self.get_current_user()
         spawner_options_form = yield user.spawner.get_options_form()
         return self.render_template('spawn.html',
-            user=user,
+            for_user=for_user,
             spawner_options_form=spawner_options_form,
             error_message=message,
             url=self.request.uri,
@@ -105,7 +105,7 @@ class SpawnHandler(BaseHandler):
 
         or triggers spawn via redirect if there is no form.
         """
-        user = self.get_current_user()
+        user = current_user = self.get_current_user()
         if for_user is not None and for_user != user.name:
             if not user.admin:
                 raise web.HTTPError(403, "Only admins can spawn on behalf of other users")
@@ -120,7 +120,7 @@ class SpawnHandler(BaseHandler):
             self.redirect(url)
             return
         if user.spawner.options_form:
-            form = yield self._render_form()
+            form = yield self._render_form(for_user=user)
             self.finish(form)
         else:
             # Explicit spawn request: clear _spawn_future
@@ -135,7 +135,7 @@ class SpawnHandler(BaseHandler):
     @gen.coroutine
     def post(self, for_user=None):
         """POST spawns with user-specified options"""
-        user = self.get_current_user()
+        user = current_user = self.get_current_user()
         if for_user is not None and for_user != user.name:
             if not user.admin:
                 raise web.HTTPError(403, "Only admins can spawn on behalf of other users")
@@ -161,9 +161,11 @@ class SpawnHandler(BaseHandler):
             yield self.spawn_single_user(user, options=options)
         except Exception as e:
             self.log.error("Failed to spawn single-user server with form", exc_info=True)
-            self.finish(self._render_form(str(e)))
+            form = yield self._render_form(message=str(e), for_usr=user)
+            self.finish(form)
             return
-        self.set_login_cookie(user)
+        if current_user is user:
+            self.set_login_cookie(user)
         url = user.url
 
         next_url = self.get_argument('next', '')

jupyterhub/tests/test_pages.py

@@ -174,6 +174,17 @@ def test_spawn_page(app):
         assert FormSpawner.options_form in r.text
 
 
+@pytest.mark.gen_test
+def test_spawn_page_admin(app):
+    with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
+        cookies = yield app.login_user('admin')
+        u = add_user(app.db, app=app, name='melanie')
+        r = yield get_page('spawn/' + u.name, app, cookies=cookies)
+        assert r.url.endswith('/spawn/' + u.name)
+        assert FormSpawner.options_form in r.text
+        assert "Spawning server for {}".format(u.name) in r.text
+
+
 @pytest.mark.gen_test
 def test_spawn_form(app):
     with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):

share/jupyterhub/templates/spawn.html

@@ -7,11 +7,14 @@
     <h1>Spawner options</h1>
   </div>
   <div class="row col-sm-offset-2 col-sm-8">
-      {% if error_message %}
-        <p class="spawn-error-msg text-danger">
-          Error: {{error_message}}
-        </p>
-      {% endif %}
+    {% if for_user and user.name != for_user.name -%}
+      <p>Spawning server for {{ for_user.name }}</p>
+    {% endif -%}
+    {% if error_message -%}
+      <p class="spawn-error-msg text-danger">
+        Error: {{error_message}}
+      </p>
+    {% endif %}
     <form enctype="multipart/form-data" id="spawn_form" action="{{url}}" method="post" role="form">
       {{spawner_options_form | safe}}
       <br>