Fc Optimize Docker Compose

Service Properties Order

• Principle: Maintain consistent property order for readability.
• Standard Order:
  • container_name
  • image
  • platform
  • build
  • healthcheck
  • ssh
  • ports
  • volumes
  • depends_on
  • networks

Resource Limits

• Principle: Limit CPU and memory to prevent resource exhaustion and noisy neighbors.
• Key Points:
  • Set cpu_limits and memory_limits to prevent excessive consumption
  • Set resource requests for guaranteed minimum resources
  • Monitor resource usage to tune limits appropriately
• Example Docker Compose Resource Limits

Persistent Storage

• Principle: Use persistent volumes to maintain data across container restarts.
• Key Points:
  • Use named volumes, bind mounts, or cloud storage
  • Never store persistent data inside container's writable layer
  • Implement backup strategies for persistent data
  • Choose storage solutions that meet performance requirements
• Example Docker Volume Usage

Networking

• Principle: Use defined container networks for secure and isolated communication.
• Key Points:
  • Create separate networks for different application tiers or environments
  • Use service discovery features for automatic service discovery
  • Implement network policies to control traffic between containers
  • Implement proper network segmentation for multi-tier applications
• Example Docker Network Configuration

Platform

• Principle: Specify the target platform for compatibility across different environments.
• Key Points:
  • Use platform option to specify target architecture (e.g., linux/amd64, linux/arm64)
  • Ensures correct base images and binaries are used for the target platform
  • Important for CI/CD pipelines and cross-environment development (e.g., MacOS arm64 vs Linux amd64)
• Example Docker Compose with Platform Specification

Health Checks

• Principle: Define health checks to monitor service health.
• Key Points:
  • Use healthcheck property with command, interval, and timeout
  • Design checks specific to application functionality, not just process status
  • Set appropriate intervals and timeouts to balance responsiveness with overhead
  • Consider both liveness and readiness checks for complex applications
• Example Docker Compose with Health Checks

Network Configuration

• Principle: Define custom networks for service isolation and communication control.
• Key Points:
  • Use networks property to create custom networks
  • Connect services that need to communicate to the same network while isolating others
  • Choose appropriate network drivers (e.g., bridge, overlay) based on deployment environment
  • Consider network policies or firewall rules for additional security
• Example Docker Network Configuration

SSH Configuration

• Principle: Configure SSH access securely for private dependencies.
• Key Points:
  • Use SSH agent forwarding to access host SSH keys without copying them
  • Mount SSH socket and configuration files into the container
  • Ensure proper permissions are set on SSH keys
  • Use multi-stage builds to limit SSH access to build stage only
• Example Docker Compose with SSH Configuration

Environment Variable Management

• Principle: Use environment variables to manage configuration and secrets securely.
• Key Points:
  • Use environment property to define environment variables per service
  • Use .env files for different environments without hardcoding in Compose file
  • Create .env.template files to document required variables and expected values
  • CRITICAL: Add .env files to .gitignore to prevent committing sensitive information
  • Use Docker Secrets or external secrets management for sensitive data

Validation and Linting

• Principle: Validate Docker Compose files for syntax and best practices.
• Key Points:
  • Use docker-compose config to validate syntax and view merged configuration
  • Use docker-compose up --dry-run to check for potential issues without starting containers
  • Use linters like docker-compose-linter or hadolint for best practice checks
  • Integrate validation and linting into CI/CD pipelines for automated checks
  • Continuous improvement from errors found during builds and linting, indicate in the report what needs to be added to fc-optimize-docker-compose skill next time.

Dockerfile Review Checklist

• CRITICAL: is .env file included in .gitignore ?
• Are resource limits defined for CPU and memory?
• Are persistent volumes used for stateful applications?