Size of the images golang and alpine vary by around 300Mb.
What are the advantages of using golang image instead of plain alpine?
Short answer: It would be fairer to compare the differences between golang:alpine and alpine.
At the time of writing, the golang image is built off of Debian, a different distribution than Alpine. I'll quote the documentation from Docker Hub:
golang:<version>This is the defacto image. If you are unsure about what your needs are, you probably want to use this one. It is designed to be used both as a throw away container (mount your source code and start the container to start your app), as well as the base to build other images off of.
and
golang:alpineThis image is based on the popular Alpine Linux project, available in the alpine official image. Alpine Linux is much smaller than most distribution base images (~5MB), and thus leads to much slimmer images in general.
This variant is highly recommended when final image size being as small as possible is desired. The main caveat to note is that it does use musl libc instead of glibc and friends, so certain software might run into issues depending on the depth of their libc requirements. However, most software doesn't have an issue with this, so this variant is usually a very safe choice. See this Hacker News comment thread for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
In summary, images built off of Alpine will tend to be smaller than the Debian ones. But, they won't contain various system tools that you may find useful for development and debugging. A common compromise is to build your binaries with the golang flavor and deploy to production with either golang:alpine, alpine, or as mentioned in a comment above, scratch.
Why not scratch or centurylink ?
You can build a static go binary file and copy it into the docker image.
The size of the docker image will be equal to the size of the binary file.
Suppose that your go binary file is called main_go, this is the Dockerfile that you need:
FROM centurylink/ca-certs
ADD main_go /
CMD ["/main_go"]
Please remember that scratch and centurylink are blank images therefore you must statically compile your app with all libraries built in.
Example:
CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main_go .
Here you can find some extra info about docker, go and scratch and here you can find some info about the GOOS value.