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Andrew
Andrew

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Docker Best Practices for Production Deployments

#docker #devops #containerization

Docker Best Practices for Production 🐳

Multi-Stage Builds: Cut Image Size by 70% 

FROM node:18 AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production

FROM node:18-alpine
COPY --from=builder /app/node_modules ./node_modules
COPY . .
USER node
EXPOSE 3000
CMD ["node", "app.js"]
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Result: 900MB → 120MB image size

Security Hardening

Run as Non-Root 

RUN useradd -m appuser
USER appuser
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Remove Package Manager 

RUN apt-get purge -y --auto-remove apt-get
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Scan for Vulnerabilities 

docker run --rm -v /var/run/docker.sock:/var/run/docker.sock aquasec/trivy image myapp:latest
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Performance Optimization

  1. Layer Caching - Order commands from least to most frequently changed
  2. Use .dockerignore - Exclude unnecessary files
  3. Minimize Layers - Combine RUN commands with && 
# Bad: 3 layers
RUN apt-get update
RUN apt-get install curl
RUN rm -rf /var/lib/apt/lists/*

# Good: 1 layer
RUN apt-get update && apt-get install -y curl && rm -rf /var/lib/apt/lists/*
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Container Networking

Health Checks 

HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD curl -f http://localhost:3000/health || exit 1
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Port Exposure 

EXPOSE 3000 8080
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Production Checklist

  • ✅ Non-root user
  • ✅ Security scanning passed
  • ✅ Health checks defined
  • ✅ Resource limits set
  • ✅ Logging configured
  • ✅ No secrets in image

Master these practices and your deployments will be rock solid. 🚀

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