docker-optimizerlisted

# Docker Optimizer Analyzes and optimizes Dockerfiles for performance, security, and best practices. ## When to Use - User working with Docker or containers - Dockerfile optimization needed - Container image too large - User mentions "Docker", "container", "image size", or "deployment" ## Instructions ### 1. Find Dockerfiles Search for: `Dockerfile`, `Dockerfile.*`, `*.dockerfile` ### 2. Check Best Practices **Use specific base image versions:** ```dockerfile # Bad FROM node:latest # Good FROM node:18-alpine ``` **Minimize layers:** ```dockerfile # Bad RUN apt-get update RUN apt-get install -y curl RUN apt-get install -y git # Good RUN apt-get update && \ apt-get install -y curl git && \ rm -rf /var/lib/apt/lists/* ``` **Order instructions by change frequency:** ```dockerfile # Dependencies change less than code COPY package*.json ./ RUN npm install COPY . . ``` **Use .dockerignore:** ``` node_modules .git .env *.md ``` ### 3. Multi-Stage Builds Reduce final image size: ```dockerfile # Build stage FROM node:18 AS build WORKDIR /app COPY package*.json ./ RUN npm install COPY . . RUN npm run build # Production stage FROM node:18-alpine WORKDIR /app COPY --from=build /app/dist ./dist COPY --from=build /app/node_modules ./node_modules CMD ["node", "dist/index.js"] ``` ### 4. Security Issues **Don't run as root:** ```dockerfile RUN addgroup -S appgroup && adduser -S appuser -G appgroup USER appuser ``` **No secrets in image:** ```dockerfile # Bad: Hardco