Curated Dockerfiles examples

This repository contains examples of Dockerfiles using the best practices that docker recommends. This approach allows to build a Docker image with a minimal footprint, by copying only the necessary files from the build stage to the final image and using non-root user to run the application.

For more information about multi stage builds, please refer to the official documentation.

📊 Comparativa de tamaños de imágenes Docker

Esta tabla muestra la diferencia de tamaño entre los Dockerfiles sin optimizar (.old) y los Dockerfiles optimizados con multi-stage builds y mejores prácticas.

Imagen	Dockerfile.old	Dockerfile (Optimizado)	Tiempo de Build
go/simple	870MB	2.13MB	20s
go/simple_with_packages	874MB	2.14MB	19s
java/distroless	586MB	192MB	24s
java/maven	586MB	287MB	35s
java/simple	323MB	211MB	7s
node/backend	1.13GB	63.7MB	13s
node/nextjs	❌	48.6MB	30s
python/flask	1.44GB	85.5MB	38s
python/simple	❌	873MB	1m 7s
rust/simple	1.47GB	8.34MB	10s

🤝 ¿Quieres contribuir? Añade tus propios ejemplos y ayuda a la comunidad a ver el impacto de las buenas prácticas en Docker. ¡La tabla se actualiza automáticamente con cada push!

Los valores se actualizan automáticamente mediante GitHub Actions.

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Best practices and security checks

• Use a lightweight image.
• Minimun number of layers.
• Optimize build order.
  • Install OS packages and dependencies first (cache in another image).
  • Copy library definitions first, then build.
• Multi-stage.
  • Avoid compilers.
  • Avoid caching the build process.
• Avoid using the root user.
• File permissions (when copying from the builder).
• Sort multi-line arguments.
• Exclude with dockerignore.

Examples by language or technology

• Java
• Python
• Node
• Go
• Rust

How to use these examples

Each example contains a Dockerfile and Dockerfile.old. The .old file contains simple Dockerfile without multi stage builds and the Dockerfile contains the multi stage build version.

To build the image, you can use the following command:

docker build -t <image_name> .

If you want to build the image using the old Dockerfile, you can use the following command:

docker build -t <image_name> -f Dockerfile.old .

To run the image, you can use the following command:

docker run -it <image_name>

How contribute to this repository

If you want to contribute to this repository, please follow these steps:

1. Fork this repository
2. Add your example in a new folder or update an existing example (always grouped by language or technology). This example must to contain a curated dockerfile and an old version called "dockerfile.old" to exemplify the less optimized version.
3. Create a pull request with your changes