Act Runner in docker container

Hello,

I followed the documentation on

to create a runner with the docker image, using docker-compose, but two problems occurred:

a) docker-compose.yml says that local file ./config.yaml shall be mounted on
/config.yaml, but with this, docker complains and tells me that I am probably
trying to mount a file on a directory or vice versa

b) when I remove that volume completely from docker-compose.yml, the
container starts, but the Gitea web interface shows the runner as offline
and I do not know how to set it online. Furthermore, the docker container
complains that it cannot find a file .runner

Regards
Christoph

Here is my working runner, created via docker compose

  runner:
    image: gitea/act_runner:latest
    container_name: act_runner_global
    restart: always
    environment:
      CONFIG_FILE: '/config.yaml'
      GITEA_INSTANCE_URL: 'https://git.example.com/'
      GITEA_RUNNER_REGISTRATION_TOKEN: 'yOuR_sEcReT_tOkEn'
      GITEA_RUNNER_NAME: 'ubuntu_global'
    networks:
      - 'gitea_network'
    ports:
      - '8081:8081'
    depends_on:
      gitea:
        condition: service_healthy
        restart: true
    volumes:
      - ./act_runner/config.yaml:/config.yaml
      - ./act_runner/data:/data
      - /var/run/docker.sock:/var/run/docker.sock