UPX

Overview

A small image for usage in multi-stage Docker builds to compress binary files like Go or Rust. Based on the official busybox image and build via multi-stage build himself to make the image as small as possible ~1.7MB For more information on the great tool UPX check out their GitHub project!

Usage

CMD

To compress any file run following command

$ docker run --rm -w $PWD -v $PWD:$PWD gruebel/upx:latest --best --lzma -o [compressed file name] [file name]

Docker multi-stage build

For this example I used the official example of the Docker documentation for multi-stage builds

FROM golang:1.7.3 as builder
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v golang.org/x/net/html  
COPY app.go    .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

# Before copying the Go binary directly to the final image,
# add them to the intermdediate upx image
FROM gruebel/upx:latest as upx
COPY --from=builder /go/src/github.com/alexellis/href-counter/app /app.org

# Compress the binary and copy it to final image
RUN upx --best --lzma -o /app /app.org

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=upx /app .
CMD ["./app"]