docker-compose dns and python docker api nested container

If you want to set up a Docker Compose environment with nested containers, particularly involving DNS resolution and a Python application interacting with the Docker API, you’ll need to configure your docker-compose.yml file accordingly. Here’s a basic example to get you started:

Let’s assume you have three services:

1. Python application using Docker API (python-app)
2. DNS resolver (e.g., dnsmasq)
3. Your main application container (main-app)

Here’s a sample docker-compose.yml file:

version: '3'

services:
  python-app:
    build: ./python-app
    networks:
      - custom-network
    depends_on:
      - main-app

  dnsmasq:
    image: your-dnsmasq-image
    networks:
      - custom-network

  main-app:
    build: ./main-app
    networks:
      - custom-network
    dns:
      - dnsmasq

networks:
  custom-network:

In this example:

• python-app is your Python application using the Docker API. Ensure that your Python app’s code properly connects to the Docker daemon using the appropriate Docker SDK (e.g., docker-py).
• dnsmasq is a DNS resolver. You might need to create a custom Docker image with dnsmasq configured according to your needs.
• main-app is your main application container. It will use the DNS resolver (dnsmasq) for DNS resolution.

Make sure to replace your-dnsmasq-image with the actual image you want to use for the DNS resolver. You may also need to adjust the paths in the build section according to your project structure.

This setup ensures that the python-app and main-app services share a custom network (custom-network), and the main-app container uses dnsmasq for DNS resolution. This way, you have a basic structure for nesting containers, using DNS resolution, and interacting with the Docker API from a Python application.

Remember to adapt this example to your specific requirements and make sure your Python application is configured correctly to connect to the Docker daemon inside its container.