Modern software development requires robust DevOps practices. Docker and Kubernetes have become the industry standard for containerization and orchestration. This guide will walk you through building a complete, production-ready CI/CD pipeline.
Why Docker and Kubernetes?
Docker provides consistent environments from development to production, while Kubernetes offers:
- Automatic scaling based on demand
- Self-healing capabilities
- Rolling updates with zero downtime
- Resource management and optimization
- Multi-cloud portability
Docker Best Practices
Multi-Stage Builds
Use multi-stage builds to create smaller, more secure images. Separate build dependencies from runtime dependencies, reducing image size by up to 80%.
FROM node:18-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build
FROM node:18-alpine AS runtime
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
CMD ["node", "dist/index.js"]Layer Caching
Order Dockerfile instructions from least to most frequently changing. Copy package files before source code to leverage Docker's layer caching, dramatically speeding up builds.
Security Hardening
Run containers as non-root users, scan images for vulnerabilities, and use minimal base images (Alpine Linux). Regularly update base images to patch security vulnerabilities.
Kubernetes Architecture
Deployments and ReplicaSets
Use Deployments to manage your application lifecycle. They provide:
- Rolling updates and rollbacks
- Desired state management
- Scaling capabilities
Services and Ingress
Services provide stable network endpoints for pods. Use ClusterIP for internal communication, NodePort or LoadBalancer for external access, and Ingress for HTTP/HTTPS routing with SSL termination.
CI/CD Pipeline Setup
GitHub Actions Workflow
A typical CI/CD pipeline includes:
- Code checkout and dependency installation
- Running tests (unit, integration, E2E)
- Building Docker images
- Pushing to container registry
- Deploying to Kubernetes
- Running smoke tests
Blue-Green Deployments
Implement blue-green deployments in Kubernetes for zero-downtime updates. Run two identical production environments, switch traffic between them, and keep the previous version ready for instant rollback.
Monitoring and Observability
Essential monitoring tools for Kubernetes:
- Prometheus: Metrics collection and alerting
- Grafana: Visualization and dashboards
- ELK Stack: Log aggregation and analysis
- Jaeger: Distributed tracing
Resource Management
Properly configure resource requests and limits:
- Requests: Guaranteed resources for the container
- Limits: Maximum resources a container can use
- Use Horizontal Pod Autoscaler for automatic scaling
- Implement Vertical Pod Autoscaler for right-sizing
Real-World Implementation
We implemented a complete Docker/Kubernetes pipeline for a SaaS platform serving 100,000+ users. The results:
- 99.9% uptime with automatic failover
- 50% reduction in infrastructure costs
- Deployment time reduced from 2 hours to 5 minutes
- Automatic scaling handles 10x traffic spikes
Conclusion
Docker and Kubernetes form the foundation of modern DevOps practices. By following these best practices and implementing a complete CI/CD pipeline, you can achieve faster deployments, better reliability, and significant cost savings. Start with the basics and gradually adopt more advanced features as your needs grow.