allow for workflows that export all env vars

[johnswanson]

loom here: https://www.loom.com/share/761bb56d52c6424d93d5cb4ea924bb53?sid=96faa314-71b6-40bb-b3d6-c7eefe798f0d

when developing locally, I really like the following flow:

• launch a new postgres db with ./run-postgres-latest.sh

• be able to programmatically set the necessary env vars so that Metabase connects to that new postgres DB

• later, being able to programmatically switch to a different AppDB (e.g. back and forth between postgres and mariadb)

I've been using a hacky version of these dev tools for a while to accomplish that and figured I'd fix things up and push to see if this workflow appealed to anyone else.

The following scripts have changed in the exact same way for mariadb, mysql, and postgres:

First, ./run-$db-latest.sh now sets one additional context variable: [DATABASE]_BROAD_VERSION. This allows us to figure out the right container for, e.g. oldest postgres, without worrying about whether the oldest version when you started the DB was v1 and now it's v2

Second, ./_run-$db.sh now:

• starts the container, then
• runs source ./env-$db.sh, before
• spitting out a human-readable message about how to connect to the database.

Finally, ./env-$db.sh now:

• takes a "broad version" (latest or oldest)

• pulls data from the container itself, reducing duplication (e.g. it figures out what the MYSQL_DATABASE you launched mysql with was, rather than making sure it's in sync)

• can be run two ways:

  • ./env-postgres.sh latest spits out the old user-readable message about how to connect to postgres
  • source ./env-postgres.sh latest doesn't output anything - it sets env vars like MB_DB_HOST, MB_DB_USER, etc. so that your metabase backend will automatically use this AppDB.
  • (for postgres, but not mariadb/mysql, it'll also set the necessary env vars so you can run psql without any args and connect to the app DB)

One other change: the docker run commands no longer explicitly set a host port. Instead we just expose a public port, and the ./env-$db.sh scripts use port=$(docker port ${container} 3306/tcp | cut -d: -f2) to figure out the appropriate host port.

Personally, I use this like so:

(defun metabase-mariadb-jack-in! ()
  (interactive)
  (shell-command "/Users/jds/src/dev-scripts/run-mariadb-latest.sh")
  (metabase-mariadb-jack-in "latest"))

(defun metabase-mariadb-oldest-jack-in! ()
  (interactive)
  (shell-command "/Users/jds/src/dev-scripts/run-mariadb-oldest.sh")
  (metabase-mariadb-jack-in "oldest"))

(defun metabase-mariadb-jack-in (version)
  "Connect to MariaDB and start metabase"
  (interactive)
  (ignore-errors (cider-quit))
  (metabase-reset-env!)
  (set-env-from-shell "/Users/jds/src/dev-scripts/env-mariadb.sh" version)
  (metabase-jack-in))

This way, in emacs, I can run metabase-mariadb-oldest-jack-in! and automatically:

• blow away the old mariadb DB and launch a new one
• set the env up to connect to the new container
• and restart cider to actually connect to it

Similarly, (metabase-mariadb-jack-in "latest") kills cider, sets up the env to connect to the existing latest mariadb container I have running, and then relaunches cider.