If you ever had to build a go binary and include it in a docker container, you would either have to do a multi-stage build, which meant you couldn’t use a docker hub automated build, or you had to include the whole build environment in the image, which meant you significantly bloat it.

In docker 17.06 you can do multi-stage builds, which does away with this issue.

I’ve created a sample github repo to illustrate this,

# build stage
FROM golang:alpine AS build
COPY . /src
RUN cd /src && go build -o app

# final stage
FROM scratch
COPY --from=build /src /
CMD ["/app"]

With go binaries, you don’t even need a base image, so you can use scratch, which saves a few MB. You can see in the image list that the difference between go:golang, go:alpine and go:scatch, so doing a multistage build and using scatch will save you 257MB.

$ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED              SIZE
go                  scratch             ea0352afec72        4 seconds ago        1.59MB
go                  alpine              4bba42611772        7 minutes ago        5.55MB
go                  golang              646c6f10c26b        8 minutes ago        259MB    
golang              alpine              310e63753884        13 days ago          257MB
alpine              latest              7328f6f8b418        13 days ago          3.97MB

Unfortunately docker hub runs version 17.03.1-ee-2 at the moment, so the automated build of my github repo doesn’t work, but once they upgrade it should start building ok.


Whenever you create a docker image for production use, you should always include a HEALTHCHECK. I’ve built a very simple curl-like go program called gurl that can be included in the image and used like this

HEALTHCHECK --interval=5m --timeout=3s CMD /gurl http://localhost:8080/