[ANNOUNCE] git-scm.com Heroku credits update

[Taylor Blau <ttaylorr@github.com>]

As some of you know, we have a website at https://git-scm.com, which has
served as the Git project's de-facto homepage.

That site is hosted on Heroku, which has graciously provided the Git
project with hosting credits for many years. That, combined with support
from Cloudflare has meant that the maintenance cost for the site is
effectively $0.

Unfortunately, Heroku no longer provides free hosting credits to
organizations and open-source projects. I have been in an ongoing
support thread with them, and their stance is pretty clear.

To that end, we have a few options about what to do with the website in
the future:

  - Convert the Rails application into a static site that could be
    hosted elsewhere for free. The non-static portions of the site would
    have to become static in one way or another, and we'd have to come
    up with an alternative search mechanism to replace the existing one.

  - Explore ways to cheapen our Heroku bill (more on this later). Our
    footprint at Heroku currently is a dyno for the Rails site itself,
    along with a separate database (Postgres) and cache (Redis). We
    could explore eliminating the Rails-layer cache, and tune our
    Cloudflare settings to more aggressively cache parts of the website.

  - Pay Heroku using the Git project's funds held at Conservancy.

  - Find a cheaper Rails host.

Our Heroku bill varies slightly based on usage, but here's last month's
bill, which is more or less representative:

              | Usage (months)       | Cost $/mo |  Total
    ----------+----------------------+-----------+---------
    scheduler | 0.004941199999999998 | $25.00/mo |   $0.12
    web       | 1                    | $50.00/mo |  $50.00
    redis     | 1                    | $30.00/mo |  $30.00
    postgres  | 1                    | $50.00/mo |  $50.00
    ----------+----------------------+-----------+---------
                                                   $131.58

(I'm omitting about $1.46 of charges that come from spinning up dynos to
power "PR previews" when somebody makes a pull request to the
git/git-scm.com repository on GitHub).

I think we could reasonably get rid of the Rails-layer caching using
Redis and save some money there, but it may not be possible depending on
how much content Cloudflare is willing to keep warm in its cache.

In the meantime, Heroku is billing Git's account at Conservancy [1] in
order to keep the site running while we all figure out what to do next.
I have some opinions about what a sustainable solution looks like, but
I'll avoid sharing them just yet in order to avoid tainting the
discussion.

Thanks,
Taylor

[1]: I promised[2] an update on our financials, and am still working on
it. The Git project currently has about ~$70k USD in its account.
[2]: https://lore.kernel.org/git/Yg%2FsO63nhhtAXWvn@nand.local/