"emulating" a virtual machine / sharing one MAVLAN IP with several services in one docker-compose script

Question

I do have the following problem: I have a docker image of an home-automation system which comprises a lot of Services like: MQTT Service, Web-Interface, WebServer etc. so it uses a lot of ports and I did set it up in an MACVLAN container with a dedicated IP-Address to not expose all the ports on the physical host.

Now this service would love to use Redis as in Memory Cache, so I added another Service to my compose file and was almost fine excepts that I actually want redis to be exposed via the same IP as the home-automation system.

On a virtual machine or as "merged docker" image this would not be a problem: Install OS, install home-automation and redis or deploy it within one docker image.

It would also not be an issue if I would use bridge mode network and expose all ports on the host, but I prefer having a dedicated IP.

This is how far I got but Redis is of course not accessible via the MACVLAN_IP of the home-automation-system

version: '3.5'

services: 
  iobroker:
    container_name: iobroker
    image: buanet/iobroker
    hostname: iobroker
    restart: unless-stopped

    #ports > Not explicitly exposed as on MACVLAN it creates a virtual host
    environment:
      - IOB_STATESDB_HOST=iobroker-redis
      - IOB_STATESDB_PORT=6379
      - IOB_STATESDB_TYPE=redis
    volumes:
      - ....
    depends_on:
      - redis      
    networks:
      my-macvlan:
        ipv4_address: 192.168.177.6
      my-bridgenetwork:
                
  redis:
    container_name: iobroker-redis
    image: redis:latest
    hostname: redis
    restart: unless-stopped
    ports:
      - "6379:6379"
    volumes:
      - ....
    command: redis-server /usr/local/etc/redis/redis.conf      
    networks:
       my-bridgenetwork:
    
networks:
  my-macvlan:
    external: true
  my-bridgenetwork:
    external: true    

any ideas how I could get redis to be accessible on the MACVLAN-IP 192.168.177.6 in my example?

I already tried using

network_mode: service: iobroker

for the redis-service but this is not working as it create a cycle as the redis container seems to require, that the underlying service container was started but the service container itself relies on redis.

I read that you could create a "parent container" acting as a host for the MACVLAN IP and then adding two containers in "network mode container" but I could not find any example for it.