Use static linking when building Go binaries for Docker image

[evanmcclure]

This will create larger binaries. However, the Docker base image can be swapped out for a distroless image such as scratch, which will make the resulting Docker image smaller.

One aspect to consider is whether the CGO versions of dependencies are used, as this can effect how the statically linked binaries are built.

[evanmcclure]

In case you're interested, here's an excellent, recent article about building Go binaries statically. It includes useful info about CGO and cross-compilation, too.

https://golangnews.org/2020/04/statically-compiling-go-programs-2/