A VM provides the first 4 anyway - if you're deploying to a cloud instance then having these in the container is redundant. If you're deploying to bare metal then it's possibly useful, but only if you're deploying multiple containers to the same machine.

Go doesn't need a format for packaging - it's one file. It's becoming common practice to embed everything else into the binary. (side note: I haven't done this with env files yet, and tend to deploy them separately, but I don't see any reason why we don't do this and produce binaries targetted at the specific deployment environments. I might give it a go).

I kinda prefer makefiles for the build stuff, or even just a script. The whole process of creating a Docker instance, pushing source files to it, trigging go build and then pulling back the binary seems redundant; there's no advantage of doing this in a container over doing it on the local machine. And it's a lot faster on the local machine.

Talking to people, it appears to be as mholt said: everyone just does everything in containers so apparently we do this too.