AgentSkillsCN

multi-stage-dockerfile

为任何语言或框架生成优化的多阶段Dockerfile

SKILL.md
--- frontmatter
name: multi-stage-dockerfile
description: 'Create optimized multi-stage Dockerfiles for any language or framework'

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
  • •Ensure the runtime image has the minimal necessary dependencies

Layer Optimization

  • •Organize commands to maximize layer caching
  • •Place commands that change frequently (like code changes) after commands that change less frequently (like dependency installation)
  • •Use .dockerignore to prevent unnecessary files from being included in the build context
  • •Combine related RUN commands with && to reduce layer count
  • •Consider using COPY --chown to set permissions in one step

Security Practices

  • •Avoid running containers as root - use USER instruction to specify a non-root user
  • •Remove build tools and unnecessary packages from the final image
  • •Scan the final image for vulnerabilities
  • •Set restrictive file permissions
  • •Use multi-stage builds to avoid including build secrets in the final image

Performance Considerations

  • •Use build arguments for configuration that might change between environments
  • •Leverage build cache efficiently by ordering layers from least to most frequently changing
  • •Consider parallelization in build steps when possible
  • •Set appropriate environment variables like NODE_ENV=production to optimize runtime behavior
  • •Use appropriate healthchecks for the application type with the HEALTHCHECK instruction