Build Multi-Platform Docker Images

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Containers share the host kernel, which means that the code that’s running inside the container must be compatible with the host’s architecture. This is why you can’t run a linux/amd64 container on an arm64 host (without using emulation), or a Windows container on a Linux host.

Multi-platform builds solve this problem by packaging multiple variants of the same application into a single image. This enables you to run the same image on different types of hardware, such as development machines running x86-64 or ARM-based Amazon EC2 instances in the cloud, without the need for emulation.

Using a custom builder to build a multi-platform Docker image

Creating a custom builder that uses a driver with multi-platform support, such as the docker-container driver, will let you build multi-platform images without switching to a different image store. However, you still won’t be able to load the multi-platform images you build into your Docker Engine image store. But you can push them to a container registry directly with docker build --push.

1. To create a custom builder, use the docker buildx create command to create a builder that uses the docker-container driver.

docker buildx create \
  --name my-multi-platform-builder \
  --driver docker-container \
  --bootstrap --use

2. Build and push an image to a container registry

docker build \
  --builder my-multi-platform-builder \
  --platform linux/amd64,linux/arm64 \
  --tag IMAGE_NAME \
  --push .
  • The format of IMAGE_NAME: <dockerhub_username>/<application_name>:<tag>

References

[1] Multi-platform builds - Docker Docs