title: Traefik version 2 only shows 404 or no website at all
body: <p>I try to set up Traefik in version 2 but I only get "404 Page not found" or <code>DNS_PROBE_FINISHED_NXDOMAIN</code> errors in my browser. </p>
  
  <p>When I check the API endpoints for routers I can see that my two containers are enabled in Traefik and that the rules are correct.</p>
  
  <pre><code>curl http://localhost:8080/api/http/routers
  
  [{"entryPoints":["web","secure"],"service":"gotify-gotify","rule":"Host(`sub2.example.org`)","tls":{"certResolver":"letsencrypt"},"status":"enabled","using":["secure","web"],"name":"gotify@docker","provider":"docker"},{"entryPoints":["web","secure"],"service":"nextcloud-cloud","rule":"Host(`sub.example.org`)","tls":{"certResolver":"letsencrypt"},"status":"enabled","using":["secure","web"],"name":"nextcloud@docker","provider":"docker"}]
  </code></pre>
  
  <p>But on "sub2" I get no website at all and on "sub" I get "404 page not found". I have set a DNS entry for "*" so all subdomains go to the same server.</p>
  
  <p>I have set the following labels for the docker containers</p>
  
  <pre><code>labels:
  traefik.enable: true
  traefik.http.routers.nextcloud.rule: "Host(`sub.example.org`)"
  traefik.http.routers.nextcloud.entrypoints: "web, secure"
  traefik.http.routers.nextcloud.tls.certresolver: "letsencrypt"
  </code></pre>
  
  <p>And this is my Traefik configuration <code>traefik.tom</code>l</p>
  
  <pre><code>[entryPoints]
    [entryPoints.web]
      address = ":80"
    [entryPoints.secure]
      address = ":443"
  
  [providers.docker]
    exposedByDefault = false
    network = "traefik"
  
  [certificatesResolvers.letsencrypt.acme]
    email = "me@example.org"
    storage = "acme.json"
    [certificatesResolvers.letsencrypt.acme.httpChallenge]
      entryPoint = "web"
  
  [api]
    insecure = true
    debug = true
    dashboard = false
  </code></pre>
  
  <p>Traefik itself is running as a docker container.</p>
  
  <pre><code>version: "3.7"
  
  services:
    traefik:
      image: traefik:v2.0
      container_name: traefik
      restart: unless-stopped
      volumes:
      - "./traefik.toml:/etc/traefik/traefik.toml"
      - "./acme:/etc/traefik/acme"
      - "/var/run/docker.sock:/var/run/docker.sock"
      ports:
      - "80:80"
      - "127.0.0.1:8080:8080"
      - "443:443"
      networks:
      - traefik
  
  networks:
    traefik:
      driver: bridge
      name: traefik
  </code></pre>
  
  <p>I use <code>ufw</code> to manage firewall rules and opened port 22, 80 and 443</p>
  
  <pre><code>Status: active
  
  To                         Action      From
  --                         ------      ----
  22/tcp                     ALLOW       Anywhere
  80/tcp                     ALLOW       Anywhere
  443/tcp                    ALLOW       Anywhere
  22/tcp (v6)                ALLOW       Anywhere (v6)
  80/tcp (v6)                ALLOW       Anywhere (v6)
  443/tcp (v6)               ALLOW       Anywhere (v6)
  </code></pre>