christian, I was asked to “patch up” a group's Mastodon server that was still running an unpatched version 4.0.x.
When I was done, they asked me how I did it so quickly. Here is a #HowTo:
– back up DB
– check out v4.1.15
– follow these upgrade notes: https://github.com/mastodon/mastodon/releases/tag/v4.1.0 (!)
– test– back up DB
– check out v4.2.8 (latest)
– follow these upgrade notes: https://github.com/mastodon/mastodon/releases/tag/v4.2.0 (!)
– test→ Follow upgrade notes for each version x.y.0, or you will miss migrations!