Multi-stage builds create smaller, more secure Docker images. Here's how to use them effectively.
Why Multi-Stage Builds
Single-stage problems:
- Build tools in production image
- Large image sizes
- Security vulnerabilities from dev dependencies
- Slow deployments
Multi-stage benefits:
- Separate build and runtime
- Smaller final images
- No build tools in production
- Better security posture
Basic Multi-Stage Build
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TypeScript Application
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Next.js Application
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Go Application
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Python Application
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Optimizing Layer Caching
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Using Build Arguments
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Testing Stage
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Size Comparison
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Best Practices
Structure:
✓ Use specific base image tags
✓ Order layers by change frequency
✓ Minimize layer count
✓ Use .dockerignore
Security:
✓ Run as non-root user
✓ Don't include secrets in image
✓ Scan images for vulnerabilities
✓ Use minimal base images
Performance:
✓ Leverage build cache
✓ Use --mount=type=cache for package managers
✓ Parallelize independent stages
✓ Clean up in same layer as install
Conclusion
Multi-stage builds separate build-time dependencies from runtime, resulting in smaller, more secure images. Structure Dockerfiles to maximize cache hits, use Alpine or distroless base images, and always run as non-root in production.