Can you explain what BuildKit is and how it differs from previous Docker build systems?

BuildKit is a modern image building system for Docker that improves performance and functionality compared to the traditional Docker Build.

Differences and advantages of BuildKit:

• Parallel build: allows multiple Dockerfile steps to run simultaneously, speeding up the process.
• Caching: smarter and more flexible caching, including caching of intermediate layers and cache export.
• Support for new Dockerfile features: for example, RUN --mount=type=cache for caching data between steps.
• Enhanced security: isolation of build stages.
• Progress and log output: more informative and user-friendly.

To enable BuildKit, simply set the environment variable:

export DOCKER_BUILDKIT=1

Thus, BuildKit makes image building faster, more efficient, and more flexible.