DNS Problems Traefik+Cloudflare

Hi,

I want to setup Gitea+Drone+Traefik with Cloudflare Proxy

I created the following docker-compose definitions

gitea:
    image: "gitea/gitea:latest"
    container_name: "gitea"
    hostname: "git.example.com"
    restart: "unless-stopped"
    environment:
      USER_UID: "1000"
      USER_GID: "1000"
      DB_TYPE: "postgres"
      DB_HOST: "gitea-db:5432"
      DB_NAME: "gitea"
      DB_USER: "example"
      DB_PASSWD: "example"
      ROOT_URL: "https://git.example.com"
      SSH_DOMAIN: "git.example.com"
      SSH_PORT: ""
    networks:
      - "proxy"
      - "default"
    volumes:
      - "/etc/timezone:/etc/timezone:ro"
      - "/etc/localtime:/etc/localtime:ro"
      - "/opt/docker/data/gitea/data:/data"
    depends_on:
      - "db"
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.gitea.entrypoints=https"
      - "traefik.http.routers.gitea.rule=Host(`git.example.com`)"
      - "traefik.http.routers.gitea.tls=true"
      - "traefik.http.routers.gitea.tls.options=cloudflare@file"
      - "traefik.http.routers.gitea.service=gitea-svc"
      - "traefik.http.services.gitea-svc.loadbalancer.server.port=3000"
  db:
    image: "postgres:9.6"
    container_name: "gitea-db"
    hostname: "gitea-db"
    restart: "unless-stopped"
    environment:
      POSTGRES_USER: "example"
      POSTGRES_PASSWORD: "example"
      POSTGRES_DB: "gitea"
    volumes:
      - "/opt/docker/data/gitea/db:/data"
  drone:
    image: "drone/drone:1"
    container_name: "gitea-drone"
    hostname: "drone.example.com"
    restart: "unless-stopped"
    networks:
      - "proxy"
      - "drone"
    environment:
      DRONE_OPEN: "true"
      DRONE_GITEA: "true"
      DRONE_GITEA_CLIENT_ID: "<client id>"
      DRONE_GITEA_CLIENT_SECRET: "<client secret>"
      DRONE_GITEA_SERVER: "https://git.example.com"
      DRONE_RPC_SECRET: "<rpc secret>"
      DRONE_SERVER_HOST: "drone.example.com"
      DRONE_SERVER_PROTO: "https"
      DRONE_TLS_AUTOCERT: "false"
      DRONE_REGISTRATION_CLOSED: "true"
    depends_on:
      - "gitea"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "/opt/docker/data/gitea/drone:/data"
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.drone.entrypoints=https"
      - "traefik.http.routers.drone.rule=Host(`drone.example.com`)"
      - "traefik.http.routers.drone.tls=true"
      - "traefik.http.routers.drone.tls.options=cloudflare@file"
      - "traefik.http.routers.drone.service=drone-svc"
      - "traefik.http.services.drone-svc.loadbalancer.server.port=80"

Gitea and Traefik run fine so far. But if I want to login to drone I always get an error saying drone could not resolve git.example.com. Can you give me a hint what I’m missing?