Document how to use a persistent datomic db

[oxalorg]

Using an in-memory database and reloading data on every reset is quite annoying.

I've already figured out one way using docker to spin a persistent datomic instance on the FS, I'm exploring a little more on it and if it works I'll update the docs.

[plexus]

This is probably the easiest option https://github.com/gws/docker-datomic-free-transactor

Although I believe as it stands Cognitect has stopped updating Datomic Free, which is a shame. Instead you're supposed to register for a free trial of Datomic Pro, but that's not a great experience for someone just wanting to contribute to an open source project.

But so far we're not using any new features so we can still use Datomic free for now. Maybe eventually we'll migrate to one of the open source datalog databases. (Crux, Asami, Datahike, Datalevin)

[oxalorg]

This too works for me:

docker run -d -e ADMIN_PASSWORD="admin" -e DATOMIC_PASSWORD="datomic" -p 4334-4336:4334-4336 --name datomic-free akiel/datomic-free

[plexus]

That would be this one: https://github.com/alexanderkiel/datomic-free . Good to know!