What is the purpose of using multi-stage builds in Docker and what are their advantages?

Multi-stage builds in Docker allow creating images in multiple stages, where the first stages involve building and compiling the application, and the final stage forms a minimal image containing only the artifacts necessary for running.

Advantages:

• Significant reduction in the size of the final image, as build tools and temporary files are not included.
• Increased security by excluding unnecessary components from the image.
• Simplification of the build process and Dockerfile maintenance, as all stages are described in a single file.

Example:

FROM golang:1.20 AS builder
WORKDIR /app
COPY . .
RUN go build -o myapp

FROM alpine:latest
COPY --from=builder /app/myapp /usr/local/bin/myapp
CMD ["myapp"]