Build / Deploy to Cloudron from GitHub Actions

[jimcavoli]

I've extracted the following from one of my projects: https://gist.github.com/jimcavoli/b390565eb98f62faae821c83c8e87100

It has some added substitution for using secrets for all configurable values (I hard-coded a couple of them in the actual project), but is otherwise exactly what I use. It has a built-in cache registry that tries to minimize the build time, some simplistic retry logic, and as written is triggered when a new release is published on the repo. I've had a pretty good experience using it, so figured it might be handy for others, in case you've got some fully-custom app you're deploying from a private registry. The only built-in assumption is that you use the Dockerfile.cloudron naming scheme, but you could edit that as well if you like.