Multi-Stage Builds

Summary

A Dockerfile technique using multiple FROM stages to keep the final image small — compiling or building in one stage, then copying only the necessary output into a lean final image.

• 1Convert a single-stage Dockerfile into a multi-stage build and compare final image sizes.
• 2Learn why a smaller final image improves both deploy speed and reduces attack surface.
• 3Practice a multi-stage build for a compiled language where build tools shouldn't ship to production.