Pointing a Discourse container at an external postgresql and redis server using our container image with our tooling is a supported install.
RDS[1] is Postgresql, and Elasticache is Redis, this is fine.
This should be fine we do this for people moving onto our hosting.
My preference is to keep the process as simple as possible, so if you can run a full backup (including uploads) on the old server and restore it to the new, that lets you fully test out the new setup without any impact on the old one.
ok, Postgresql RDS ↩︎