Configuration Guide

The Docker Compose Wrapper uses a flexible configuration system based on YAML files and environment-specific overrides.

Configuration Files

1. Chart.yaml

The main chart metadata file that defines basic information about your application:

name: myapp
version: 1.0.0
description: My Application Chart
type: application

2. values.yaml

Default configuration values for your application:

global:
  projectName: myapp
  environment: development

services:
  web:
    image: myapp/web:latest
    replicas: 1
    ports:
      - "8080:80"
    environment:
      - NODE_ENV=development
    volumes:
      - ./data:/app/data
    networks:
      - frontend
    rollingUpdate:
      replicas: 2
      retryCount: 5
      retryInterval: 10

3. Environment-specific Values

Create environment-specific configuration files in the environments directory:

# environments/prod.yaml
global:
  environment: production

services:
  web:
    image: myapp/web:prod
    replicas: 3
    environment:
      - NODE_ENV=production

Value Precedence

Values are merged in the following order (highest to lowest precedence):

1. Command-line arguments
2. Environment-specific values
3. Default values from values.yaml
4. Chart defaults

Configuration Structure

Global Values

Global values apply to all services:

global:
  projectName: myapp
  environment: development
  domain: example.com
  registry: docker.io

Service Configuration

Service-specific configuration:

services:
  web:
    # Basic configuration
    image: myapp/web:latest
    replicas: 1
    
    # Networking
    ports:
      - "8080:80"
    networks:
      - frontend
    
    # Environment variables
    environment:
      - NODE_ENV=development
      - DB_HOST=db
    
    # Volumes
    volumes:
      - ./data:/app/data
      - config:/app/config
    
    # Rolling update configuration
    rollingUpdate:
      replicas: 2
      retryCount: 5
      retryInterval: 10

Network Configuration

Define custom networks:

networks:
  frontend:
    driver: bridge
  backend:
    driver: bridge
    internal: true

Volume Configuration

Define named volumes:

volumes:
  db_data:
  config:

Template Usage

Use Go templates in your configuration files:

services:
  web:
    image: /
    environment:
      - NODE_ENV=

Best Practices

1. Value Organization
   • Keep global values at the root level
   • Group service-specific values under services
   • Use environment-specific overrides for differences
2. Environment Management
   • Keep environment-specific changes minimal
   • Use environment variables for sensitive data
   • Document environment-specific requirements
3. Template Usage
   • Use helper templates for common patterns
   • Keep templates DRY (Don’t Repeat Yourself)
   • Use conditional rendering for optional features
4. Security
   • Never commit sensitive data to version control
   • Use environment variables for secrets
   • Consider using a secrets management solution

Common Configuration Patterns

Development Environment

# environments/dev.yaml
global:
  environment: development

services:
  web:
    image: myapp/web:dev
    replicas: 1
    environment:
      - DEBUG=true

Production Environment

# environments/prod.yaml
global:
  environment: production

services:
  web:
    image: myapp/web:prod
    replicas: 3
    environment:
      - DEBUG=false

Staging Environment

# environments/staging.yaml
global:
  environment: staging

services:
  web:
    image: myapp/web:staging
    replicas: 2
    environment:
      - DEBUG=false