docker-compose/watchtower/docker-compose.yml

# https://linuxiac.com/watchtower-automatically-update-docker-container-images/

services:
  watchtower:
    image: containrrr/watchtower
    env_file: .env
    mem_limit: 512m
    restart: always
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      WATCHTOWER_SCHEDULE: "0 0 7 * * *"
      TZ: Europe/Rome
      WATCHTOWER_MONITOR_ONLY: true
      WATCHTOWER_CLEANUP: true
      WATCHTOWER_NOTIFICATIONS: email
      WATCHTOWER_NOTIFICATIONS_HOSTNAME: ${WATCHTOWER_NOTIFICATIONS_HOSTNAME}
      WATCHTOWER_NOTIFICATION_EMAIL_FROM: ${WATCHTOWER_NOTIFICATION_EMAIL_FROM}
      WATCHTOWER_NOTIFICATION_EMAIL_TO: ${WATCHTOWER_NOTIFICATION_EMAIL_TO}
      WATCHTOWER_NOTIFICATION_EMAIL_SERVER: ${WATCHTOWER_NOTIFICATION_EMAIL_SERVER}
      WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT: ${WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT}
      WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER: ${WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER}
      WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD: ${WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD}