Merge pull request #5146 from agoose77/fix-spawn-429

set HTTP status when spawn via GET params fails

jupyterhub/apihandlers/users.py

@@ -24,6 +24,7 @@ from ..roles import assign_default_roles
 from ..scopes import needs_scope
 from ..user import User
 from ..utils import (
+    format_exception,
     isoformat,
     iterate_until,
     maybe_future,
@@ -865,9 +866,8 @@ class SpawnProgressAPIHandler(APIHandler):
                 failed_event['message'] = "Spawn cancelled"
             elif f and f.done() and f.exception():
                 exc = f.exception()
-                message = getattr(exc, "jupyterhub_message", str(exc))
+                message, html_message = format_exception(exc)
                 failed_event['message'] = f"Spawn failed: {message}"
-                html_message = getattr(exc, "jupyterhub_html_message", "")
                 if html_message:
                     failed_event['html_message'] = html_message
             else:
@@ -906,9 +906,8 @@ class SpawnProgressAPIHandler(APIHandler):
                 failed_event['message'] = "Spawn cancelled"
             elif f and f.done() and f.exception():
                 exc = f.exception()
-                message = getattr(exc, "jupyterhub_message", str(exc))
+                message, html_message = format_exception(exc)
                 failed_event['message'] = f"Spawn failed: {message}"
-                html_message = getattr(exc, "jupyterhub_html_message", "")
                 if html_message:
                     failed_event['html_message'] = html_message
             else:

jupyterhub/handlers/pages.py

@@ -15,7 +15,13 @@ from tornado.httputil import url_concat
 from .. import __version__, orm
 from ..metrics import SERVER_POLL_DURATION_SECONDS, ServerPollStatus
 from ..scopes import describe_raw_scopes, needs_scope
-from ..utils import maybe_future, url_escape_path, url_path_join, utcnow
+from ..utils import (
+    format_exception,
+    maybe_future,
+    url_escape_path,
+    url_path_join,
+    utcnow,
+)
 from .base import BaseHandler
 
 
@@ -92,7 +98,9 @@ class SpawnHandler(BaseHandler):
 
     default_url = None
 
-    async def _render_form(self, for_user, spawner_options_form, message=''):
+    async def _render_form(
+        self, for_user, spawner_options_form, message='', html_message=''
+    ):
         auth_state = await for_user.get_auth_state()
         return await self.render_template(
             'spawn.html',
@@ -100,6 +108,7 @@ class SpawnHandler(BaseHandler):
             auth_state=auth_state,
             spawner_options_form=spawner_options_form,
             error_message=message,
+            html_error_message=html_message,
             url=url_concat(
                 self.request.uri, {"_xsrf": self.xsrf_token.decode('ascii')}
             ),
@@ -177,7 +186,6 @@ class SpawnHandler(BaseHandler):
         await spawner.run_auth_state_hook(auth_state)
 
         # Try to start server directly when query arguments are passed.
-        error_message = ''
         query_options = {}
         for key, byte_list in self.request.query_arguments.items():
             query_options[key] = [bs.decode('utf8') for bs in byte_list]
@@ -185,6 +193,8 @@ class SpawnHandler(BaseHandler):
         # 'next' is reserved argument for redirect after spawn
         query_options.pop('next', None)
 
+        spawn_exc = None
+
         if len(query_options) > 0:
             try:
                 self.log.debug(
@@ -200,16 +210,31 @@ class SpawnHandler(BaseHandler):
                     "Failed to spawn single-user server with query arguments",
                     exc_info=True,
                 )
-                error_message = str(e)
+                spawn_exc = e
                 # 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)
+
+            # Explicitly catch HTTPError and report them to the client
+            # This may need scoping to particular error codes.
+            if isinstance(spawn_exc, web.HTTPError):
+                self.set_status(spawn_exc.status_code)
+
+                for name, value in spawn_exc.headers.items():
+                    self.set_header(name, value)
+
+            if spawn_exc:
+                error_message, error_html_message = format_exception(spawn_exc)
+            else:
+                error_message = error_html_message = None
+
             form = await self._render_form(
                 for_user=user,
                 spawner_options_form=spawner_options_form,
                 message=error_message,
+                html_message=error_html_message,
             )
             self.finish(form)
         else:
@@ -265,9 +290,23 @@ class SpawnHandler(BaseHandler):
             self.log.error(
                 "Failed to spawn single-user server with form", exc_info=True
             )
+
+            # Explicitly catch HTTPError and report them to the client
+            # This may need scoping to particular error codes.
+            if isinstance(e, web.HTTPError):
+                self.set_status(e.status_code)
+
+                for name, value in e.headers.items():
+                    self.set_header(name, value)
+
+            error_message, error_html_message = format_exception(e)
+
             spawner_options_form = await user.spawner.get_options_form()
             form = await self._render_form(
-                for_user=user, spawner_options_form=spawner_options_form, message=str(e)
+                for_user=user,
+                spawner_options_form=spawner_options_form,
+                message=error_message,
+                html_message=error_html_message,
             )
             self.finish(form)
             return
@@ -379,6 +418,8 @@ class SpawnPendingHandler(BaseHandler):
             if isinstance(exc, web.HTTPError):
                 status_code = exc.status_code
             self.set_status(status_code)
+
+            message, html_message = format_exception(exc, only_jupyterhub=True)
             html = await self.render_template(
                 "not_running.html",
                 user=user,
@@ -386,8 +427,8 @@ class SpawnPendingHandler(BaseHandler):
                 server_name=server_name,
                 spawn_url=spawn_url,
                 failed=True,
-                failed_html_message=getattr(exc, 'jupyterhub_html_message', ''),
+                failed_html_message=html_message,
-                failed_message=getattr(exc, 'jupyterhub_message', ''),
+                failed_message=message,
                 exception=exc,
             )
             self.finish(html)

jupyterhub/utils.py

@@ -984,3 +984,13 @@ def fmt_ip_url(ip):
     if ":" in ip:
         return f"[{ip}]"
     return ip
+
+
+def format_exception(exc, *, only_jupyterhub=False):
+    """
+    Format an exception into a text string and HTML pair.
+    """
+    default_message = None if only_jupyterhub else str(exc)
+    return getattr(exc, "jupyterhub_message", default_message), getattr(
+        exc, "jupyterhub_html_message", None
+    )

share/jupyterhub/templates/spawn.html

@@ -14,7 +14,11 @@
         {% 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 alert alert-danger">Error: {{ error_message }}</p>{% endif %}
+        {% if error_message %}
+          <p class="spawn-error-msg alert alert-danger">Error: {{ error_message }}</p>
+        {% elif error_html_message %}
+          <p class="spawn-error-msg alert alert-danger">{{ error_html_message | safe }}</p>
+        {% endif %}
         <form enctype="multipart/form-data"
               id="spawn_form"
               action="{{ url | safe }}"