What are Docker multi-stage builds and how do they work?

What are Docker multi-stage builds and how do they work?

Docker multi-stage builds allow you to use multiple FROM statements in your Dockerfile. This helps in optimizing the image size by separating the build environment from the final runtime environment.

Can you give me an example of a multi-stage build?

Sure! Here's a simple example:

# First stage: build the application
FROM node:14 AS build
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build

# Second stage: serve the application
FROM nginx:alpine
COPY --from=build /app/build /usr/share/nginx/html
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

What are the benefits of using multi-stage builds?

The benefits include reduced image size, improved build times, and better separation of concerns, making your Docker images cleaner and more efficient.

Are there any drawbacks to using multi-stage builds?

One potential drawback is increased complexity in your Dockerfile, which might make it harder to understand for newcomers. However, the benefits often outweigh this.