systemctl-mqtt/docker-compose.yml

version: '2.2'

volumes:
  config:

services:
  mqtt_client:
    build: .
    image: fphammerle/systemctl-mqtt
    volumes:
    - config:/etc/systemctl-mqtt:ro
    - /var/run/dbus/system_bus_socket:/var/run/dbus/system_bus_socket:rw
    command: systemctl-mqtt
      --mqtt-host mqtt-broker.local
      --mqtt-username raspberrypi
      --mqtt-password-file /etc/systemctl-mqtt/mqtt-password
    hostname: raspberrypi
    userns_mode: host
    # prefering explicit user specification over "USER 0" in Dockerfile
    # to avoid accidental container startup without
    # secure apparmor profile and dropped capabilities
    user: '0'
    read_only: true
    cap_drop: [all]
    security_opt:
    - no-new-privileges
    # $ sudo apparmor_parser --replace ./docker-apparmor-profile
    # raspberrypi kernel apparmor: https://github.com/raspberrypi/linux/pull/1698#issuecomment-684989048
    # https://github.com/raspberrypi/linux/commit/a3e07c5dfef2664fc1d900ebb4a3f91c04ab700b
    - apparmor=systemctl-mqtt
    # docker-compose >=2.2,<3
    cpus: 0.4
    mem_limit: 32M

# https://docs.docker.com/compose/compose-file/compose-file-v2/