Idea: amaru GitHub action

[jeluard]

Implement a GitHub action allowing to sync periodically an amaru node. This node can then be used by others GitHub actions steps.

As inspiration, see an existing solution for cardano-node.

[abailly]

On a somewhat related note, I thought it would be useful to start publishing amaru snapshots (eg. database?), even if the format will change over time

[jeluard]

Great point!

[KtorZ]

If someone wants to pick this up, and as the author of cardanoSolutions/gh-action-cardano-node-ogmios-docker-sync; few things I would love to see:

1. Some ways to also control the sync-level until which synchronise; This is mostly a setting that's useful to bypass GitHub's limitation regarding long-running workflow jobs (iirc, capped at 6h). It's also useful
2. A better that actually partially solves (1) is to allow a timeout or "maximum run time" to the job, ensuring a clean stop is done when reaching the timeout.
3. Right now, we use this action for our own setup in Amaru, although the cached artifact are a bit too large; so we have to manually prune the immutable db of the node, to remove old blocks (beyond the maximum rollback point) that are not needed for syncing and following the chain. Amaru will very likely have similar issues; and it would be nice to have an option for automatically pruning the dbs after the sync is done (or interrupted via timeout). So that we have an easier time implementing a nightly sync job than we did for Amaru.