This changes the site to run on Debian 10 instead of Ubuntu 16.04. It
also fully converts the previous Salt setup to use Ansible instead.
Most of this was a relatively straightforward conversion, and it should
be very close to equivalent. One notable difference is that I removed
the setup for the "monitoring" server, since I wasn't confident that the
way of setting up self-hosted Sentry and Grafana was working any more.
I'll look to re-add that at some point, but it's not urgent.
Previously tild.es urls would proxy_pass through to the views inside the
Pyramid app, but this caused strange behavior in some cases. For
example, anything that caused a 404 response would end up in a broken
page that still appeared to be on the tild.es domain, but would be an
HTML-only page coming from the app, since the CSS and JS would not be
available.
This method is still a bit weird in some ways (now you'll end up on a
404 page at https://tildes.net/shortener/... instead), but I think it's
an improvement overall.
Links aren't displayed/used anywhere yet, but this should be the basic
setup needed for a simple link-shortener on the tild.es domain.
Currently, it will support two uses:
* https://tild.es/asdf - redirect to topic with id "asdf"
* https://tild.es/~asdf - redirect to group "~asdf"