multi-stage-dockerfile

Source: github/awesome-copilot - skills/multi-stage-dockerfile/SKILL.md

Your goal is to help me create efficient multi-stage Dockerfiles that follow best practices, resulting in smaller, more secure container images.

Multi-Stage Structure

• Use a builder stage for compilation, dependency installation, and other build-time operations
• Use a separate runtime stage that only includes what's needed to run the application
• Copy only the necessary artifacts from the builder stage to the runtime stage
• Use meaningful stage names with the AS keyword (e.g., FROM node:18 AS builder)
• Place stages in logical order: dependencies -> build -> test -> runtime

Base Images

• Start with official, minimal base images when possible
• Specify exact version tags to ensure reproducible builds (e.g., python:3.11-slim not just python)
• Consider distroless images for runtime stages where appropriate
• Use Alpine-based images for smaller footprints when compatible with your application