A multi-stage build results in a smaller Docker image by allowing you to separate the build environment from the final runtime environment. Here's how it works:
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Multiple Stages: You define multiple
FROMstatements in your Dockerfile, each representing a different stage. The first stage is typically used for building the application (e.g., compiling code, installing dependencies). -
Selective Copying: After building the application, you can copy only the necessary artifacts (like compiled binaries) from the build stage to the final stage. This means you don't include any build tools, source code, or unnecessary files in the final image.
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Reduced Layers: The final image contains fewer layers because it only includes the essential components needed to run the application, leading to a smaller overall size.
By using this technique, you eliminate the overhead of development dependencies and files, resulting in a leaner, more efficient image suitable for production.
