Docker BuildKit Optimizations Cheat Sheet

Last Updated: November 21, 2025

Optimization Focus

Feature	Why use it
`Cache mounts`	Mount type=cache for package downloads and tools.
`Secret mounts`	Keep credentials out of images with RUN --mount=type=secret.
`Multi-stage builds`	Separate builder dependencies from runtime artifacts.
`Concurrent steps`	BuildKit executes independent steps in parallel.


         DOCKER_BUILDKIT=1 docker build --secret id=npmrc,src=.npmrc .

Provide private registry credentials securely.


         docker buildx build --cache-from=type=registry,ref=repo:cache --cache-to=type=inline

Push caches for CI reuse.


         RUN --mount=type=cache,target=/root/.cache/pip pip install -r requirements.txt

Speed up Python builds.


         docker buildx du --progress=plain

Inspect cache layers and size.

BuildKit speeds up builds by caching downloads, isolating secrets, and running independent steps simultaneously.

💡 Pro Tip: Enable BuildKit by default with DOCKER_BUILDKIT=1 and monitor docker buildx du for cache usage.