traefik-external-routing-config.yml

http:
  routers:
    pihole:
      entryPoints:
        - "https"
      rule: "Host(`pihole.example.com`)"
      middlewares:
        - default-headers
        - addprefix-pihole
      tls:
        certResolver: http
      service: pihole

  services:
    pihole:
      loadBalancer:
        servers:
          - url: "http://192.168.0.10:80"
        passHostHeader: true

  middlewares:
    addprefix-pihole:
      addPrefix:
        prefix: "/admin"

    https-redirect:
      redirectScheme:
        scheme: https

    default-headers:
      headers:
        frameDeny: true
        sslRedirect: true
        browserXssFilter: true
        contentTypeNosniff: true
        forceSTSHeader: true
        stsIncludeSubdomains: true
        stsPreload: true

    default-whitelist:
      ipWhiteList:
        sourceRange:
        - "10.0.0.0/24"
        - "192.168.0.0/16"
        - "172.0.0.0/8"

    secured:
      chain:
        middlewares:
        - default-whitelist
        - default-headers