Multi-Architecture Images

Multi-arch images

Images only work on a single platform

But containers are supported on multiple architectures and operating systems

Virtual images to the rescue

Manifest links to separate image per platform

Now integrated in Docker CLI (docker manifest)

Based on manifest-tool (by Docker Captain Phil Estes)

Official images are already multi-arch

Multi-Arch Image: hello-world

$ regctl manifest get --list hello-world
Name:        hello-world
  Platform:  linux/amd64
  Platform:  linux/arm/v5
  Platform:  linux/arm/v7
  Platform:  linux/arm64/v8
  Platform:  linux/386
  Platform:  linux/mips64le
  Platform:  linux/ppc64le
  Platform:  linux/riscv64
  Platform:  linux/s390x
  Platform:  windows/amd64
  OSVersion: 10.0.20348.288
  Platform:  windows/amd64
  OSVersion: 10.0.17763.2237

Multi-Arch Image: docker

$ regctl manifest get --list docker:latest
Name:        docker:latest
  Platform:  linux/amd64
  Platform:  linux/arm64/v8

Demo: Building for other Architectures 020_advanced/140_multi_arch

Prepare for new sub command buildx

Enable qemu:

docker run --rm --privileged tonistiigi/binfmt --install all

Create builder:

docker buildx create --name mybuilder --use
docker buildx inspect --bootstrap

Demo: Building for other Architectures 020_advanced/140_multi_arch

Build multi-arch:

docker buildx build \
    --platform linux/arm,linux/arm64,linux/amd64 \
    --tag localhost:5000/nicholasdille/hello \
    . \

Inspect result:

docker buildx imagetools inspect \

Demo: Build multi-arch with proper tags (1) 020_advanced/140_multi_arch

Build individual images to control tagging

Build for arm, arm64 and amd64:

docker buildx build --platform linux/arm \
    --tag localhost:5000/nicholasdille/hello:arm . --push
docker buildx build --platform linux/arm64 \
    --tag localhost:5000/nicholasdille/hello:arm64 . --push
docker buildx build --platform linux/amd64 \
    --tag localhost:5000/nicholasdille/hello:amd64 . --push

Test new images:

docker run localhost:5000/nicholasdille/hello:arm
docker run localhost:5000/nicholasdille/hello:arm64
docker run localhost:5000/nicholasdille/hello:amd64

This allows for proper versioning

Demo: Build multi-arch with proper tags (2) 020_advanced/140_multi_arch

Create manifest list with all images:

docker manifest create --amend --insecure \
    localhost:5000/nicholasdille/hello \
    localhost:5000/nicholasdille/hello:arm \
    localhost:5000/nicholasdille/hello:arm64 \
docker manifest inspect localhost:5000/nicholasdille/hello