Multi-stage Dockerfile

[Doug]

https://docs.docker.com/engine/userguide/eng-image/multistage-build/

---

FROM golang:1.7 as builder

MAINTAINER Oliver [e-mail]

WORKDIR /go/src/github.com/oliver006/rethinkdb_exporter
ENV GOPATH /go
COPY . /go/src/github.com/oliver006/rethinkdb_exporter

RUN go get
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o rethinkdb_exporter .

FROM alpine:latest
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/github.com/oliver006/rethinkdb_exporter/rethinkdb_exporter .
ENTRYPOINT ["./rethinkdb_exporter"]

[Oliver]

Thanks!

I'll have a look into multi-stage as this might come in handy to reduce the image size. An alternative way to do this would be to change the build process and not build the binary in the docker image but separately and then just COPY it in (see redis_exporter as an example here: https://github.com/oliver006/redis_exporter/blob/master/Dockerfile#L1-L7)

[Oliver]

Also, I'm not sure if CircleCI is on the latest docker version yet that's needed for multi-stage builds.