Have you encountered the cryptic error message "error: multiple platforms feature is currently not supported for docker driver" while trying to build Docker images? Fear not, fellow developer, for this post will shed light on this issue and guide you towards solutions.

Understanding the Problem

This error arises when you attempt to build a Docker image targeting multiple architectures (platforms) within a single build process using the default Docker driver. The Docker driver, in this context, refers to the engine component responsible for managing image creation on your system.

Why This Happens?

Docker, by default, focuses on building images for the architecture of your host machine (e.g., x86_64 on most modern systems). The "multiple platforms feature" refers to the ability to create an image that can run on different architectures. While Docker itself offers multi-arch support with the buildx command, the standard Docker driver lacks this functionality.

Solutions and Workarounds:

There are a couple of ways to address this limitation:

Embrace Docker Buildx

Docker Buildx is a next-generation builder toolkit integrated with Docker. It offers advanced features like building images for multiple architectures in a single command. To leverage this functionality, you can use the following steps:

• Install Buildx:

docker buildx --help
Extended build capabilities with BuildKit

Usage:  docker buildx [OPTIONS] COMMAND

Extended build capabilities with BuildKit

Options:
      --builder string   Override the configured builder instance

Management Commands:
  imagetools  Commands to work on images in registry

Commands:
  bake        Build from a file
  build       Start a build
  create      Create a new builder instance
  dial-stdio  Proxy current stdio streams to builder instance
  du          Disk usage
  inspect     Inspect current builder instance
  ls          List builder instances
  prune       Remove build cache
  rm          Remove one or more builder instances
  stop        Stop builder instance
  use         Set the current builder instance
  version     Show buildx version information

Run 'docker buildx COMMAND --help' for more information on a command.

Experimental commands and flags are hidden. Set BUILDX_EXPERIMENTAL=1 to show them.

Ensure you have Buildx installed. It's usually included with Docker Desktop on macOS and Windows or can be installed separately on Linux.

• Create a new Builder:

Use the following command to create a named builder instance.

$ docker buildx create --name my-builder

• Use the new Builder:

$ docker buildx use mybuilder

• Build Multi-Platform Images:

Run the docker buildx build command, specifying the builder name (--name my-builder), the platforms you want to target (--platform linux/amd64,linux/arm64), and the Dockerfile location.

docker buildx build --platform linux/amd64,linux/arm64,linux/arm/v7 -t username/demo:latest --push .
 => pushing layers                                                             2.7s
 => pushing manifest for docker.io/username/demo:latest                       2.2

Build Separate Images

If Buildx isn't an option, you can build separate Docker images for each target architecture. This requires creating individual Dockerfiles with architecture-specific instructions or using build arguments to switch between architectures within a single Dockerfile. This approach can be more cumbersome for managing multiple images.

Refer to the official Docker documentation for detailed instructions on using Docker Buildx and building multi-platform images: https://docs.docker.com/reference/cli/docker/buildx/

Conclusion:

The "multiple platforms feature not supported" error is a common hurdle when building Docker images for various architectures. By understanding the limitation and exploring the solutions provided, you can effectively build and deploy containerized applications across different hardware environments. So, the next time you encounter this error, remember there's a path forward for creating those multi-platform Docker images!