Container Development

Expert knowledge for containerization and orchestration with focus on lean, secure container images and 12-factor app methodology.

Core Expertise

Container Image Construction

• Dockerfile/Containerfile Authoring: Clear, efficient, and maintainable container build instructions
• Multi-Stage Builds: Creating minimal, production-ready images
• Image Optimization: Reducing image size, minimizing layer count, optimizing build cache
• Security Hardening: Non-root users, minimal base images, vulnerability scanning

Container Orchestration

• Service Architecture: Microservices with proper service discovery
• Resource Management: CPU/memory limits, auto-scaling policies, resource quotas
• Health & Monitoring: Health checks, readiness probes, observability patterns
• Configuration Management: Environment variables, secrets, configuration management

Key Capabilities

• 12-Factor Adherence: Ensures containerized applications follow 12-factor principles, especially configuration and statelessness
• Health & Reliability: Implements proper health checks, readiness probes, and restart policies
• Skaffold Workflows: Structures containerized applications for efficient development loops
• Orchestration Patterns: Designs service meshes, load balancing, and container communication
• Performance Tuning: Optimizes container resource usage, startup times, and runtime performance

Image Crafting Process

1. Analyze: Understand application dependencies and build process
2. Structure: Design multi-stage Dockerfile, separating build-time from runtime needs
3. Ignore: Create comprehensive .dockerignore file
4. Build & Scan: Build image and scan for vulnerabilities
5. Refine: Iterate to optimize layer caching, reduce size, address security
6. Validate: Ensure image runs correctly and adheres to 12-factor principles

Best Practices

Multi-Stage Dockerfile Pattern

# Build stage
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
RUN npm run build

# Production stage
FROM node:20-alpine
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001
WORKDIR /app
COPY --from=builder --chown=nodejs:nodejs /app/dist ./dist
COPY --from=builder --chown=nodejs:nodejs /app/node_modules ./node_modules
USER nodejs
EXPOSE 3000
CMD ["node", "dist/main.js"]

Security Best Practices

• Use minimal base images (alpine, distroless)
• Run containers as non-root user
• Implement health checks for container reliability
• Scan images for vulnerabilities regularly
• Keep base images updated

12-Factor App Principles

• Configuration via environment variables
• Stateless processes
• Explicit dependencies
• Port binding for services
• Graceful shutdown handling

Skaffold Preference

• Favor Skaffold over Docker Compose for local development
• Continuous development loop with hot reload
• Production-like local environment

For detailed Dockerfile optimization techniques, orchestration patterns, security hardening, and Skaffold configuration, see REFERENCE.md.