Shortlink url breakage

[jameslzhu]

Currently, all shortlinks are naked, in the sense that these urls are resolved without additional prefixes:

https://hkn.eecs.berkeley.edu/<shortlink>
https://hkn.mu/<shortlink>

As currently implemented in hknweb, however, shortlinks are namespaced behind s/. In other words, all shortlink urls are only accessible at:

https://hkn.eecs.berkeley.edu/s/<shortlink>
https://hkn.mu/s/<shortlink>

This will break many existing urls to our website (decal, member signup, serv, studrel, etc.), even if namespacing is desirable. The fix should involve routing shortlinks in the root hknweb/urls.py, passing on all urls that match no other urls to the shortlinks app.

[jameslzhu]

Related conversation on the OCF issue tracker (https://leprosy.ocf.berkeley.edu/forum/t/ocf-io-shorturls/48).

The OCF suggests four necessary pieces for a good solution:

• Separate namespacing for "temporary" urls: urls that are used for throwaway / one-time events, or are not publicly distributed (posters, word-of-mouth, whiteboards, etc.) (i.e. hkn.mu/s/temp_url
• Database schema: storing shortlinks in SQL, with "static" permanent links (/mail) and "prepend" links like (/prot/Computing_Services) which pass on the rest of the URL.
• Web server: return a redirect (see https://docs.djangoproject.com/en/1.10/ref/contrib/redirects/#how-to-add-change-and-delete-redirects)
• UI: web UI with text fields OR slackbot (would be super impressive, fame and glory await you)

[jameslzhu]

So things you should do:

1. Make the shortlinks accessible without the /s/ prefix. Make sure website paths take precedence over shortlink paths.
2. Validate shortlinks are unique: this should be done in the shortlinks/models.py somehow. This is a combination of SlugField and the unique option.
3. What's that leader field in Links? why?
4. Can we change Links plural to Link singular?

[jameslzhu]

One more thing I'd like you guys to do is build some kind of edit interface for this (a form to create a new shortlink).