server version display

also tests

jupyterhub/app.py

@@ -1185,6 +1185,10 @@ class JupyterHub(Application):
         False, help="""Shuts down all user servers on logout"""
     ).tag(config=True)
 
+    server_tokens = Bool(
+        True, help="""Display JupyterHub version information on admin page"""
+    ).tag(config=True)
+
     @default('statsd')
     def _statsd(self):
         if self.statsd_host:
@@ -2133,6 +2137,7 @@ class JupyterHub(Application):
             internal_ssl_ca=self.internal_ssl_ca,
             trusted_alt_names=self.trusted_alt_names,
             shutdown_on_logout=self.shutdown_on_logout,
+            server_tokens=self.server_tokens,
             eventlog=self.eventlog,
         )
         # allow configured settings to have priority

jupyterhub/handlers/pages.py

@@ -14,6 +14,7 @@ from tornado import gen
 from tornado import web
 from tornado.httputil import url_concat
 
+from .. import __version__
 from .. import orm
 from ..metrics import SERVER_POLL_DURATION_SECONDS
 from ..metrics import ServerPollStatus
@@ -422,6 +423,8 @@ class AdminHandler(BaseHandler):
             sort={s: o for s, o in zip(sorts, orders)},
             allow_named_servers=self.allow_named_servers,
             named_server_limit_per_user=self.named_server_limit_per_user,
+            server_tokens=self.settings.get('server_tokens', True),
+            server_version='{} {}'.format(__version__, self.version_hash),
         )
         self.finish(html)
 

jupyterhub/tests/test_pages.py

@@ -110,6 +110,21 @@ async def test_admin(app):
     assert r.url.endswith('/admin')
 
 
+async def test_admin_version(app):
+    cookies = await app.login_user('admin')
+    r = await get_page('admin', app, cookies=cookies, allow_redirects=False)
+    r.raise_for_status()
+    assert "version_footer" in r.text
+
+
+async def test_admin_version_disabled(app):
+    cookies = await app.login_user('admin')
+    with mock.patch.dict(app.tornado_settings, {'server_tokens': False}):
+        r = await get_page('admin', app, cookies=cookies, allow_redirects=False)
+    r.raise_for_status()
+    assert "version_footer" not in r.text
+
+
 @pytest.mark.parametrize('sort', ['running', 'last_activity', 'admin', 'name'])
 async def test_admin_sort(app, sort):
     cookies = await app.login_user('admin')

share/jupyterhub/static/less/admin.less

@@ -1,3 +1,9 @@
 i.sort-icon {
   margin-left: 4px;
 }
+
+.version_footer {
+  position: fixed;
+  bottom: 0;
+  width: 100%;
+}

share/jupyterhub/templates/admin.html

@@ -103,6 +103,13 @@
   </tbody>
   </table>
 </div>
+{%- if server_tokens -%}
+  <div class="container-fluid navbar-default small version_footer">
+    <div class="navbar-text">
+      JupyterHub {{ server_version }}
+    </div>
+  </div>
+{%- endif -%}
 
 {% call modal('Delete User', btn_class='btn-danger delete-button') %}
   Are you sure you want to delete user <span class="delete-username">USER</span>?