Supported Docker Compose Variables

This document outlines all the Docker Compose variables that are currently supported by the docker-to-iac module when translating your docker-compose.yml file into Infrastructure as Code templates.

Core Requirements

The docker-to-iac module requires that your docker-compose.yml file meets these basic requirements:

The file must contain at least one service
Each service must specify an image property (build instructions are not supported)

Supported Service Properties

For each service in your docker-compose.yml file, the following properties are supported:

Required Properties

Property	Description	Example
`image`	The Docker image to use for the service. Must be a pre-built image available in a public registry.	`image: nginx:latest`

Optional Properties

Property	Description	Example
`ports`	List of ports to expose. Supports port mapping in standard Docker format.	`ports:` `- "8080:80"` `- "443:443"`
`command`	Override the default command of the Docker image.	`command: "npm start"`
`restart`	Container restart policy.	`restart: always`
`volumes`	List of volume mappings.	`volumes:` `- "data:/var/lib/mysql"` `- "./config:/etc/nginx/conf.d:ro"`
`environment`	Environment variables as key-value pairs.	`environment:` `NODE_ENV: production` `PORT: 3000`

Example Configuration

Here's a complete example showing all supported variables:

yaml

services:
  web:
    image: nginx:alpine
    ports:
      - "80:80"
      - "443:443"
    command: "nginx -g 'daemon off;'"
    restart: always
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
    environment:
      NGINX_HOST: example.com
      NGINX_PORT: 80

  api:
    image: node:16-alpine
    ports:
      - "3000:3000"
    command: "npm start"
    restart: always
    environment:
      NODE_ENV: production
      DATABASE_URL: mongodb://db:27017/myapp

Important Notes

Build instructions (build:) are not supported - you must use pre-built images
Services must use images that are publicly accessible
Each service must have an image property specified
Environment variables should not contain sensitive information as they will be included in the generated IaC templates
Volume definitions are supported but their implementation may vary depending on the target cloud platform

Validation

The module performs validation checks to ensure:

The docker-compose.yml file contains at least one service
Each service has an image property specified
The Docker image reference is valid and follows the expected format

If validation fails, the module will throw a DockerComposeValidationError with a descriptive message explaining the issue.

Edit on GitHub