Remove RedirectHandler

[jtpio]

Fixes #6954

Investigate #6954.

Jupyter Server already provides a redirect handler which looks at the default_url here:

https://github.com/jupyter-server/jupyter_server/blob/c5dc0f696f376e1db5a9a0cbcebb40a0bf98875c/jupyter_server/serverapp.py#L440-L451

Which means the one in notebook can likely be removed.

Testing with:

npm i -g configurable-http-proxy
jupyterhub --config jupyterhub_config.py

jupyterhub_config.py:

c = get_config()  # noqa

from jupyterhub.auth import DummyAuthenticator

c.JupyterHub.authenticator_class = DummyAuthenticator

from jupyterhub.spawner import SimpleLocalProcessSpawner

c.JupyterHub.spawner_class = SimpleLocalProcessSpawner
c.JupyterHub.bind_url = 'http://0.0.0.0:8000'
c.Spawner.default_url = '/tree'

[github-actions]

👈 Launch a Binder on branch jtpio/notebook/default-url

[jtpio]

The default_url seems to be respected properly when testing with a local jupyterhub:

jupyterhub-default-url.mp4

[jtpio]

cc @shaneknapp since you opened #6954.

In case you would be able to test this change and see if it fixes #6954.

[shaneknapp]

cc @shaneknapp since you opened #6954.

In case you would be able to test this change and see if it fixes #6954.

testing it now!

[shaneknapp]

woohoo! it works!

[jtpio]

Nice thanks @shaneknapp for testing!

@afshin I see you requested a review. Would you like to have a look as well? Otherwise this could likely go in and I'll make a patch release right after.

[jtpio]

Getting this one in and following-up with a release.

[shaneknapp]

thanks SO MUCH for fixing this and rolling out a quick release!