In impress-2020, we do a big slow query to figure out which users have
been active in trades recently. Now, we cache that timestamp on the
User model.
This won't have any immediate effect; it's to clear the way for Classic
DTI to receive the better trade ratios feature people like from 2020.
I also added some unit testing infra because I finally wanted it! for
all the ways you can trigger this timestamp lol
Note too that this is a bit of an unusually complex migration, but my
hope is that the batching and query structure and such helps it run
surprisingly fast! 🤞
Okay, so I've kept `database.yml` using the new username and password
`impress_dev`, cuz I like that it helps clarify that it's dev stuff and
is impossible to confuse with prod. (I updated my local setup to match!)
But hardcoding `host: db` into here breaks my local setup where the
database _isn't_ at the hostname `db`. So I add a way for new optional
database URL environment variables to get merged in with these settings,
and then configured the dev container to use that—and just in the most
limited override possible, to avoid duplicating stuff we don't need to.
(I could've just used the same names `DATABASE_URL_{PRIMARY,OPENNEO_ID}`
for this, but idk, I think it's confusing to have the same one for both
dev and prod, even though Rails _does_ basically do this; see below.)
Normally, the environment variable `DATABASE_URL` just _does_ this, and
you don't need to include a `url` key at all to get this behavior. But
since we've got the legacy two-database thing going on, we do this
instead! If we were to merge the `openneo_id.users` table into the
primary database, we could simplify this!
Idk why, but unlike my previous experience with Rails devcontainers, this time the setup process is running so wildly slowly?
Might just be a transient issue on my machine, maybe something that would be improved with a restart and trying again another time? Or could be something about the MySQL image that doesn't run great in this context?
In any case, I'm just gonna set this down for now!
