add trailing slash for jupyterhub proxy paths

[Adam-D-Lewis]

Reference Issues or PRs

Fixes #2383

This PR redirects any attempts to visit https://<domain>/user/.*/proxy/(\d+) to the same path, but with the trailing slash appended.
e.g.
https://nebari.quansight.dev/user/[email protected]/proxy/5333 redirects to https://nebari.quansight.dev/user/[email protected]/proxy/5333/

Value and/or benefit

Users don't expect the closing slash to be meaningful, and users often waste several hours when facing this issue. This PR removes this potential issue for users by redirecting them.

What does this implement/fix?

Put a x in the boxes that apply

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds a feature)
• Breaking change (fix or feature that would cause existing features not to work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Other (please describe):

Testing

• Did you test the pull request locally?
• Did you add new tests?

Any other comments?

[viniciusdc]

LGTM, thanks @Adam-D-Lewis !! I also thought we could use ReplacePathRegex instead, but that would lead to issues with paths from the proxied app itself. So this looks like the only viable solution indeed. Can we have a note on our docs possibly somewhere related to proxying web apps (there might be a tutorial for panel), just to let users know this is in place?

[Adam-D-Lewis]

Thanks Vini, I'll work on some docs as part of nebari-dev/nebari-docs#240