Docker compose question

Here’s the docker compose file I use. I use a different distribution that adds a few extra features.

services:
  backup:
    image: mazzolino/restic
    hostname: docker
    restart: unless-stopped
    container_name: restic-backup
    environment:
      RUN_ON_STARTUP: "true"
      BACKUP_CRON: "0 30 3 * * *"
      RESTIC_REPOSITORY: s3:s3.amazonaws.com/bucketname
      RESTIC_PASSWORD: insert-here
      RESTIC_BACKUP_SOURCES: /docker /var/www/ /srv/
      RESTIC_COMPRESSION: max
      RESTIC_PACK_SIZE: 64
      RESTIC_BACKUP_ARGS: >-
        --exclude /docker/.git
        --exclude /srv/mysql/data
        --exclude *.gz
        --no-scan
        --cleanup-cache
      RESTIC_FORGET_ARGS: >-
        --keep-last 10
        --keep-daily 7
        --keep-weekly 8
        --keep-monthly 24
      AWS_ACCESS_KEY_ID: AK__________________
      AWS_SECRET_ACCESS_KEY: insert-here
      TZ: Pacific/Auckland
      PRE_COMMANDS: |-
        # The version of docker in the container is quite old and "docker compose" doesn't seem to work properly
        docker exec mysql mysqldump -u user -h 127.0.0.1 db_name > /srv/backups/backup-name.sql
      POST_COMMANDS_SUCCESS: |-
        # /my/scripts/mail-success.sh
      POST_COMMANDS_FAILURE: |-
        # echo "Restic docker backup FAILED" | mail -s "Restic Docker Backup FAILED" -aFrom:WildPi4Server5temp\<wildpi4server5temp@mrwild.co.nz\> web@mrwild.co.nz 
        # /my/scripts/mail-failure.sh
      POST_COMMANDS_INCOMPLETE: |-
        # echo "Restic docker backup incomplete" | mail -s "Restic Docker Backup Incomplete" -aFrom:WildPi4Server5temp\<wildpi4server5temp@mrwild.co.nz\> web@mrwild.co.nz 
        # /my/scripts/mail-incomplete.sh
    volumes:
      # local:container
      - /docker/:/docker/:ro
      - /srv/:/srv/
      - /var/www/:/var/www/:ro
      # This allows the container to interact with docker on the host machine
      - /var/run/docker.sock:/var/run/docker.sock

  prune:
    image: mazzolino/restic
    hostname: docker
    container_name: restic-prune
    restart: unless-stopped
    environment:
      SKIP_INIT: "true"
      RUN_ON_STARTUP: "false"
      # Prune at 4am on the 20th day of each month
      PRUNE_CRON: "0 0 4 20 * *"
      RESTIC_REPOSITORY:  s3:s3.amazonaws.com/bucket-name
      RESTIC_PASSWORD: insert-here
      AWS_ACCESS_KEY_ID: insert-here
      AWS_SECRET_ACCESS_KEY: insert-here
      TZ: Pacific/Auckland