This repository provides the Docker image build infrastructure for Composer, the PHP dependency manager. It contains Dockerfiles for multiple Composer versions (1.10 LTS, 2.2 LTS, latest), a common entrypoint script, and GitHub Actions workflows that build multi-architecture images and push them to Docker Hub, Amazon ECR, and GitHub Container Registry. The Dockerfiles use multi-stage builds to produce both a full runtime image and a standalone binary image, with security best practices such as SHA checksum verification for downloaded artifacts. The entrypoint script wraps the Composer CLI with tini for proper signal handling and supports transparent command forwarding. The repository also includes a script for generating the official Docker library metadata and automated dependency updates via Dependabot and Renovate. It is a well-maintained, production-grade CI/CD pipeline for containerizing Composer.