Support Jupyverse as a single-user server

jupyterhub/singleuser/__init__.py

@@ -27,6 +27,11 @@ if not _extension_env:
         # default behavior:
         # - extension, if jupyter server 2
         # - older subclass app, otherwise
+        try:
+            import jupyverse_api  # noqa: F401
+
+            _as_extension = False
+        except Exception:
             try:
                 import jupyter_server
 
@@ -67,6 +72,8 @@ else:
     from .app import SingleUserNotebookApp, main
 
     # backward-compatibility
+    if SingleUserNotebookApp is not None:
+        # not Jupyverse
         JupyterHubLoginHandler = SingleUserNotebookApp.login_handler_class
         JupyterHubLogoutHandler = SingleUserNotebookApp.logout_handler_class
         OAuthCallbackHandler = SingleUserNotebookApp.oauth_callback_handler_class

jupyterhub/singleuser/app.py

@@ -9,6 +9,7 @@
     Use JUPYTERHUB_SINGLEUSER_APP='notebook' for the legacy 'classic' notebook server (requires notebook<7).
 """
 import os
+from urllib.parse import urlparse
 
 from traitlets import import_item
 
@@ -27,6 +28,7 @@ JUPYTERHUB_SINGLEUSER_APP = _app_shortcuts.get(
     JUPYTERHUB_SINGLEUSER_APP.replace("_", "-"), JUPYTERHUB_SINGLEUSER_APP
 )
 
+jupyverse = None
 
 if JUPYTERHUB_SINGLEUSER_APP:
     if JUPYTERHUB_SINGLEUSER_APP in {"notebook", _app_shortcuts["notebook"]}:
@@ -48,6 +50,11 @@ if JUPYTERHUB_SINGLEUSER_APP:
                 )
     App = import_item(JUPYTERHUB_SINGLEUSER_APP)
 else:
+    try:
+        from jupyverse_api.cli import main as jupyverse
+
+        App = None
+    except Exception:
         App = None
         _import_error = None
         for JUPYTERHUB_SINGLEUSER_APP in (
@@ -66,6 +73,9 @@ else:
             raise _import_error
 
 
+if App is None:
+    SingleUserNotebookApp = None
+else:
     SingleUserNotebookApp = make_singleuser_app(App)
 
 
@@ -77,6 +87,23 @@ def main():
         # This is a minimally extended ServerApp that does:
         # 1. ensure lab extension is enabled, and
         # 2. set default URL to `/lab`
+        if jupyverse:
+            service_url = os.environ.get("JUPYTERHUB_SERVICE_URL")
+            url = urlparse(service_url)
+            try:
+                return jupyverse.callback(
+                    open_browser=True,
+                    host=url.hostname,
+                    port=url.port,
+                    set_=[
+                        f"frontend.base_url={url.path}",
+                        f"app.mount_path={url.path}",
+                    ],
+                    disable=[],
+                )
+            except Exception:
+                return
+
         import re
 
         _version_pat = re.compile(r"(\d+)\.(\d+)")