Trafik and multiple projects with external network

Traefik Traefik v3 (latest)
1

I think it's better to make a new thread with details for my problem. I hope it's ok.

My goal is to have a Traefik Container with dnsmasq, and multiple project Container with a reference to my Traefik. For the projects, I use nginx and a separate php container.
The dnsmasq resolve the test domain to traefik container

RUN echo "address=/.test/172.20.20.30" > /etc/dnsmasq.d/test_domain.conf

My Traefik docker-compose.yml

networks:
  traefik:
    name: traefik
    ipam:
      driver: default
      config:
        - subnet: "172.20.20.0/24"

services:
  traefik:
    image: traefik:3.0
    container_name: traefik
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ....
    depends_on:
      - dnsmasq
    networks:
      traefik:
        ipv4_address: 172.20.20.30
        
  dnsmasq:
    build:
      context: .
      dockerfile: .....
    container_name: dnsmasq
    networks:
      traefik:
        ipv4_address: 172.20.20.20

My shortened project docker-compose.yml

networks:
  container1_network:
  traefik:
    external: true

services:
  nginx:
    build:
      context: .
      dockerfile: .....
    container_name: container1-nginx
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.container1.rule=Host(`container1.test`) || Host(`www.container1.test`)"
      - "traefik.http.routers.container1.entrypoints=webSecure"
      - "traefik.http.routers.container1.tls=true"
      - .......
      - "traefik.http.routers.container1.service=container1"
      - "traefik.http.services.container1.loadbalancer.server.port=80"
      - "traefik.docker.network=traefik"
    networks:
      - traefik
      - container1_network

  php:
    build:
      context: .
      dockerfile: .....
    container_name: container1-php
    restart: unless-stopped
    networks:
      - container1_network

This works great. I have my test domains (local machine has dnsmasq with defined for test domain to 127.0.0.1)

Now i have PHP Scripts, that must resolves my domainnames like container1.test. But this failed because the container resolves the test domain to localhost

ping container1.test
PING container1.test (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: seq=0 ttl=64 time=0.014 ms

My Idea was, to add the dns from traefik to PHP Container:

  php:
    build:
      context: .
      dockerfile: .....
    container_name: container1-php
    restart: unless-stopped
    dns:
      - 172.20.20.20
    networks:
      - traefik
      - container1_network

Now I can resolve my test Domain with PHP. But on each request, I get an other project in my browser under container1.test. This is because the containers from different project can communicate between them from the external network.

One solution is to rename my services to container1-php, container1-nginx,...

Is this the best option, or does anyone have any other ideas?

2

Why? Traefik will not do DNS lookups, so why have the DNS server with Traefik?