codex-universal is a Docker image that provides a universal development environment with multiple language runtimes and tools. It allows users to configure specific versions of Python, Node.js, Rust, Go, Swift, Ruby, PHP, and Java via environment variables at runtime. The image is built from Ubuntu 24.04 and includes a wide array of development tools. The architecture is monolithic but modular via environment variable-driven configuration. Key entry points are the Docker container's entrypoint script which runs setup_universal.sh and then starts a bash shell. The system relies on external package managers (apt, pyenv, nvm, rustup, etc.) and scripts from external sources for installation.
envbuilder is a CLI tool written in Go that builds and runs Dev Containers (as defined by devcontainer.json) inside Docker containers, using a forked version of Kaniko for image building. In production, it clones a Git repository, locates a devcontainer.json or Dockerfile, compiles a Dockerfile with requested features, builds the image via Kaniko (with layer caching), and then executes lifecycle scripts (onCreate, postCreate, etc.) before running an init command as a specified user. It is designed to integrate with Coder workspaces for log forwarding but can operate standalone. The architecture is a single binary with modular components: options parsing (options/), Git operations (git/), devcontainer spec handling (devcontainer/), Kaniko build orchestration (envbuilder.go), and logging (log/). It relies on system calls for user switching (setuid), execution (exec), and filesystem mounts. External dependencies include Git, Docker daemon, and the Kaniko fork. The tool supports extensive configuration via CLI flags and environment variables, with legacy variable support. Key entry points are cmd/envbuilder/main.go (CLI) and envbuilder.go (Run function). The primary data flow is: input options -> clone repo -> parse devcontainer -> compile Dockerfile -> Kaniko build -> execute lifecycle scripts -> setuid -> exec init. The tool also includes a cache probe mode for checking layer availability without full build.