Reproducing multi-arch Go build performance in `docker buildx` vs `ko`

.ko.yaml

defaultBaseImage: gcr.io/imjasonh/combined

README.md

Reproducing multi-arch Go build performance in docker buildx vs ko

https://www.docker.com/blog/faster-multi-platform-builds-dockerfile-cross-compilation-guide/

Setup

• clone https://github.com/google/ko

• for buildx, add the Dockerfile

  • this is the "fully-optimized cross-compiling Go Dockerfile" from the above article, lightly adapted for the ko codebase
  • no go mod download because ko repo uses vendor/

• for ko, add the .ko.yaml

  • this defines a base image that consists of Distroless + Windows Nanoserver, for multi-arch and multi-OS builds

• for my tests, I'm on a 2017 MBP

  • 2.8 GHz Quad-Core Intel Core i7
  • 16 GB 2133 MHz LPDDR3
  • macOS 11.6.1 (20G224)

buildx

docker buildx build . --push -t gcr.io/imjasonh/ko-buildx \
  --platform=linux/amd64,linux/arm,linux/arm64,linux/ppc64le,linux/s390x

• NB: Windows builds didn't work at all for me, so I just excluded them
• cold cache: 208s
• code change: 32s
• no-op: 8s
• image: gcr.io/imjasonh/ko-buildx@sha256:f112526706bd3197a594c45161f2a854741a8e21a73e8c88185f6674e004e9e5

ko

ko publish --platform=all ./

• cold cache: 211s
• code change: 91s
• no-op: 59s
• image: gcr.io/imjasonh/ko-ko/ko-98b8c7facdad74510a7cae0cd368eb4e@sha256:4d9166339f254f11b879257a7ebb5f5fa2cfa9c3d15f27ebb853c28c8d52d5be

Dockerfile

FROM --platform=$BUILDPLATFORM golang:1.17-alpine AS build
WORKDIR /src
COPY go.mod go.sum .
COPY . .
ARG TARGETOS TARGETARCH

RUN --mount=target=. \
    --mount=type=cache,target=/root/.cache/go-build \
    --mount=type=cache,target=/go/pkg \
    GOOS=$TARGETOS GOARCH=$TARGETARCH go build -o /out/myapp .

FROM gcr.io/imjasonh/combined
COPY --from=build /out/myapp /bin
ENTRYPOINT ["/bin/myapp"]