Containers

Docker has become the standard for containerization, but running containers in production requires following best practices for security, performance, and reliability. This guide covers essential practices for production Docker deployments. Image optimization Use multi-stage builds Reduce final image size by using multi-stage builds: # Stage 1: Build FROM node:18-alpine AS builder WORKDIR /app COPY package*.json ./ RUN npm ci COPY . . RUN npm run build # Stage 2: Runtime FROM node:18-alpine WORKDIR /app RUN addgroup -g 1001 -S nodejs && \ adduser -S nodejs -u 1001 COPY --from=builder --chown=nodejs:nodejs /app/dist ./dist COPY --from=builder --chown=nodejs:nodejs /app/node_modules ./node_modules COPY --chown=nodejs:nodejs package*.json ./ USER nodejs EXPOSE 3000 CMD ["node", "dist/index.js"] Use minimal base images Prefer Alpine or distroless images: ...

Kubernetes is powerful, but it’s also complex. This is my journey of trying to build a “simple” Kubernetes stack and the lessons learned along the way. The Goal I wanted to create a simple, maintainable Kubernetes setup for a small to medium-sized application. The requirements were: Easy to understand and maintain Cost-effective Scalable when needed Developer-friendly What I Started With Initial Stack Kubernetes: EKS (AWS) Ingress: NGINX Ingress Controller Database: Managed PostgreSQL (RDS) Monitoring: Prometheus + Grafana Logging: ELK Stack CI/CD: GitLab CI The Reality Check Complexity Crept In What started as “simple” quickly became complex: ...

Kubernetes provides several deployment strategies to ensure zero-downtime updates and safe rollouts of new application versions. Understanding these strategies is crucial for maintaining reliable production systems. Deployment strategy overview Kubernetes deployment strategies determine how new versions of your application replace old ones. The choice depends on: Risk tolerance: How critical is zero downtime? Traffic patterns: Can you route traffic to multiple versions? Rollback speed: How quickly can you revert if issues occur? Resource constraints: Can you run multiple versions simultaneously? Rolling update (default) The default Kubernetes deployment strategy gradually replaces old pods with new ones. ...

Containerized systems have unique failure modes. Here’s how to identify and prevent common issues. 1. Resource Exhaustion Memory Limits # docker-compose.yml services: app: deploy: resources: limits: memory: 512M reservations: memory: 256M CPU Throttling services: app: deploy: resources: limits: cpus: '1.0' 2. Container Restart Loops Health Checks # Dockerfile HEALTHCHECK --interval=30s --timeout=3s --start-period=40s \ CMD curl -f http://localhost:8080/health || exit 1 Restart Policies services: app: restart: unless-stopped # Options: no, always, on-failure, unless-stopped 3. Network Issues Port Conflicts services: app: ports: - "8080:8080" # host:container DNS Resolution services: app: dns: - 8.8.8.8 - 8.8.4.4 4. Volume Mount Problems Permission Issues # Fix permissions RUN chown -R appuser:appuser /app USER appuser Volume Mounts services: app: volumes: - ./data:/app/data:ro # Read-only - cache:/app/cache 5. Image Layer Caching Optimize Dockerfile # Bad: Changes invalidate cache COPY . . RUN npm install # Good: Layer caching COPY package*.json ./ RUN npm install COPY . . 6. Log Management Log Rotation services: app: logging: driver: "json-file" options: max-size: "10m" max-file: "3" 7. Security Issues Non-Root User RUN useradd -m appuser USER appuser Secrets Management services: app: secrets: - db_password environment: DB_PASSWORD_FILE: /run/secrets/db_password Prevention Strategies Set resource limits Implement health checks Use proper restart policies Monitor container metrics Test failure scenarios Use orchestration tools (Kubernetes, Docker Swarm) Conclusion Prevent container failures by: ...

Building efficient Docker images requires following best practices. Here’s how. 1. Use Multi-Stage Builds # Build stage FROM node:18 AS builder WORKDIR /app COPY package*.json ./ RUN npm ci COPY . . RUN npm run build # Production stage FROM node:18-alpine WORKDIR /app COPY --from=builder /app/dist ./dist COPY --from=builder /app/node_modules ./node_modules CMD ["node", "dist/index.js"] 2. Layer Caching # Bad: Changes invalidate cache COPY . . RUN npm install # Good: Dependencies cached COPY package*.json ./ RUN npm install COPY . . 3. Use .dockerignore node_modules .git .env dist *.log 4. Minimize Layers # Bad: Multiple layers RUN apt-get update RUN apt-get install -y python RUN apt-get install -y git # Good: Single layer RUN apt-get update && \ apt-get install -y python git && \ rm -rf /var/lib/apt/lists/* 5. Use Specific Tags # Bad: Latest tag FROM node:latest # Good: Specific version FROM node:18.17.0-alpine Best Practices Multi-stage builds Optimize layer order Use .dockerignore Minimize image size Security scanning Conclusion Build efficient Docker images! 🐳