formgrader url returns 503 error

[pjamason]

I'm getting a 503 error when I go to my formgrader url (https:///services/formgrader-beng100). I've upgraded to nbgrader 0.4 and am using the config settings in the nbgrader docs. Here's the relevant log output when I launch jupyterhub from the command line:

[I 2017-02-27 23:19:53.871 JupyterHub orm:163] Adding service formgrader-beng100 to proxy /services/formgrader-beng100 => http://127.0.0.1:9000
[D 2017-02-27 23:19:53.891 JupyterHub orm:146] Fetching POST http://127.0.0.1:8001/api/routes/services/formgrader-beng100
[FormgradeApp | WARNING] No nbgrader_config.py file found (rerun with --debug to see where nbgrader is looking)
[FormgradeApp | INFO] Serving MathJax from /home/ubuntu/miniconda3/lib/python3.5/site-packages/notebook/static/components/MathJax/MathJax.js
[FormgradeApp | INFO] Notebook server is running at http://localhost:42030/notebooks/
[FormgradeApp | INFO] The formgrader is running at http://localhost:5000/
[FormgradeApp | INFO] --> Go to http://localhost:5000/ to access the formgrader

Not sure why I'm getting the "No nbgrader_config.py file found" warning, the file is in the same directory I launch jupyterhub from (and in /etc/jupyterhub). If I run 'nbgrader formgrade' from the same location it does find it.

Here's the jupyterhub log info when I go to the formgrader url:

23:20:18.977 - error: [ConfigProxy] Proxy error:  Error: connect ECONNREFUSED 127.0.0.1:9000
    at Object.exports._errnoException (util.js:870:11)
    at exports._exceptionWithHostPort (util.js:893:20)
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1063:14)
23:20:18.978 - error: [ConfigProxy] 503 GET /services/formgrader-beng100

I'm using apache2 for SSL termination, reverse proxying and shibboleth authentication. Thanks!

[whitead]

I just troubleshot this. Can you share your relevant service config from the jupyterhub_config.py file? You can make sure you're in the correct directory by using the cwd argument to the service.

Also, up until a few hours ago, formgrader was broken for reverse-proxied jupyterhubs. You may want to update JupyterHub to master.

[jhamrick]

Yes, sharing your config would be helpful! Additionally, if you can run the nbgrader service with --debug (as suggested), that will tell you where nbgrader is looking for the config file (and give you a sense for why it can't find it).

[pjamason]

The cwd setting was incorrect. I've updated it to the course directory:

# This is the key piece which defines how JupyterHub should talk to nbgrader
c.JupyterHub.services = [
    {
        # This is the name of the service, which will be accessible at
        # yourdomain.com/services/<name>. You can customize this to be unique
        # for your class, so that you can run multiple instances of the
        # formgrader.
        'name': 'formgrader-beng100',
        'admin': True,
        'command': ['nbgrader', 'formgrade'],

        # This URL should match the IP address and port as it is set in
        # the nbgrader_config.py file.
        'url': 'http://127.0.0.1:9000',

        # This should be the full path to where the nbgrader directory lives.
        'cwd': '/home/pjamason/beng100'
    }
]

It's working now, thank you!

We're using SystemUserSpawner so I'll create the system user for the instructor, and change the cwd setting to their nbgrader/course directory .

[jhamrick]

Closing this as the issue seems to be resolved, but feel free to open another issue if you have any further questions!