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Multi Stage Builds

Docker multi-stage builds are a feature that allows you to use multiple FROM statements in a Dockerfile. Each FROM statement defines a new build stage with its own set of instructions. This enables you to build and package your application in multiple stages within a single Dockerfile.

Here's a summary of Docker multi-stage builds and why you might use them:

  1. Efficient image size: Multi-stage builds help reduce the size of your Docker images by allowing you to separate build-time dependencies from runtime dependencies. You can use one stage to compile and build your application, and another stage to package the compiled artifacts into a minimal runtime image.

  2. Reduced security surface: By separating build-time dependencies from runtime dependencies, you can minimize the attack surface of your Docker images. The final runtime image only includes the necessary components to run your application, reducing the potential impact of security vulnerabilities.

  3. Simplified build process: Multi-stage builds can simplify your build process by allowing you to use different tools and dependencies at each stage without cluttering the final image. You can use specific tools and dependencies for building and testing your application during the build stage, but exclude them from the final runtime image.

  4. Improved build performance: Multi-stage builds can improve build performance by caching intermediate build artifacts. Docker caches intermediate images between stages, so if the source code or build dependencies haven't changed, Docker can reuse the cached intermediate images, resulting in faster builds.

  5. Better maintainability: Using multi-stage builds can make your Dockerfiles more maintainable by keeping the build process organized and easy to understand. Each stage in the Dockerfile represents a logical step in the build process, making it easier to troubleshoot and modify.

Overall, Docker multi-stage builds are a powerful feature that can help you create smaller, more efficient Docker images, improve build performance, and simplify the build process for your applications.