Docker Buildx is a Docker CLI plugin that extends the native `docker build` command with advanced BuildKit capabilities. It provides a rich command surface for multi-platform builds, declarative bake files (HCL/JSON/Compose), cache management, image attestations and provenance, policy-based source verification (OPA/Rego), and interactive debugging via a Debug Adapter Protocol (DAP) server. The architecture is driver-based, supporting local Docker, Docker containers, Kubernetes, remote TCP/Unix sockets, and a cloud driver. The codebase is written in Go and follows a modular structure with clear separation between CLI commands, build orchestration, driver implementations, policy evaluation, and utility packages. It includes an extensive integration test suite and CI pipelines that test across multiple BuildKit and Docker versions.
This is a GitHub Action that wraps Docker's `buildx bake` command, enabling multi-target Docker builds within CI workflows. It parses bake definition files (HCL or JSON), translates GitHub Action inputs into bake arguments (including support for provenance, SBOM, custom outputs, and build checks), executes the build, and generates a detailed job summary with optional build record upload. The action integrates tightly with the `@docker/actions-toolkit` library to manage Docker contexts, builder instances, and GitHub API interactions. While the core action is specific to GitHub Actions, a subaction (`subaction/matrix`) demonstrates a reusable pattern for generating a multi-dimensional GitHub Actions matrix from a bake definition's targets and fields, which can be extracted and adapted for other CI systems or deployment pipelines. The repository is well-maintained with daily dependency updates and comprehensive CI tests across various buildx versions and scenarios.