What are the differences between multi-stage and single-stage Docker builds?

What are the differences between multi-stage and single-stage Docker builds?

Multi-stage builds allow you to use multiple FROM statements in your Dockerfile, enabling you to optimize the final image size by separating build dependencies from runtime dependencies. In contrast, single-stage builds compile everything in one layer, which can lead to larger images.

What are the benefits of using multi-stage builds?

The benefits include reduced image size, improved build times, and better separation of concerns. You can keep your final image clean by only including necessary files.

Are there any downsides to using multi-stage builds?

One downside is that they can be more complex to set up and maintain, especially for larger projects. Additionally, debugging can be more challenging due to the multiple layers.

Can you give an example of a multi-stage Dockerfile?

Sure! Here's a simple example:

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

# Second stage: serve the application
FROM nginx:alpine
COPY --from=builder /app/build /usr/share/nginx/html