How to Compress Docker Image Size
Reduce a prod ready Golang image from 45 MB to 4 MB 🤯
- use -ldflags=”-s -w” (45 -> 38)
- use scratch instead of distroless (38 -> 17)
- use upx to compress image (17 -> 4)
# Example with Golang project
FROM golang:1.23.0-bookworm AS build
ARG upx_version=4.2.4
RUN apt-get update && apt-get install -y --no-install-recommends xz-utils && \
curl -Ls https://github.com/upx/upx/releases/download/v${upx_version}/upx-${upx_version}-amd64_linux.tar.xz -o - | tar xvJf - -C /tmp && \
cp /tmp/upx-${upx_version}-amd64_linux/upx /usr/local/bin/ && \
chmod +x /usr/local/bin/upx && \
apt-get remove -y xz-utils && \
rm -rf /var/lib/apt/lists/*
WORKDIR /app
COPY go.mod ./
COPY go.sum ./
RUN go mod download && go mod verify
COPY . .
RUN CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -o server -a -ldflags="-s -w" -installsuffix cgo
RUN upx --ultra-brute -qq server && upx -t server
FROM scratch
COPY --from=build /app/server /server
ENTRYPOINT ["/server"]
References