BuildKit: Docker's Hidden Gem That Can Build Almost Anything
5 hours ago
- #Build Systems
- #Docker
- #BuildKit
- BuildKit is a general-purpose, pluggable build framework used by Docker, capable of producing various outputs like OCI images, tarballs, and packages.
- At its core, BuildKit uses LLB (Low-Level Build definition), a binary protocol describing a DAG of filesystem operations, enabling aggressive caching through content-addressable operations.
- BuildKit's architecture allows for pluggable frontends, meaning any program that can produce valid LLB can drive BuildKit, not just Dockerfiles.
- The solver in BuildKit executes the LLB graph, leveraging content-addressable caching at the operation level for efficiency and parallel execution.
- BuildKit supports multiple output types, including local directories, tarballs, and OCI images, making it versatile for various build needs.
- Projects like Earthly, Dagger, and Depot utilize BuildKit's LLB, showcasing its scalability and flexibility.
- A custom frontend example, apkbuild, demonstrates how BuildKit can be used to produce Alpine APK packages from a YAML spec without Dockerfiles.
- BuildKit provides a content-addressable, parallelized, and cached build engine, eliminating the need to reinvent build system fundamentals for new tools.