Mounting from persistent storage into azure multi container app

I'm trying to build a multiconatiner app with azure. I'm struggling with accessing persistent storage. In my docker-compose file I want to add the config file for my rabbitmq container. I've mounted a fileshare to the directory "/home/fileshare" which contains the def.json. On the cloud it doesn't seem to create the volume, as on startup rabbitmq can't find the file. If i do this locally and just save the file somewhere it works.

Docker Compose File:

version: '3.8'
services:

   rabbitmq:
      image: rabbitmq:3-management-alpine
      volumes:
       - /home/fileshare/def.json:/opt/rabbitmq-conf/def.json
      expose:
        - 5672
        - 15672
      environment:
        RABBITMQ_DEFAULT_USER: guest
        RABBITMQ_DEFAULT_PASS: guest
        RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS: -rabbitmq_management load_definitions "/opt/rabbitmq-conf/def.json"
      networks:
        - cloudnet 
        
networks:
   cloudnet:
      driver: bridge    

The solution to this problem seems to be to use ftp to access the webapp and save the definitions file. Docker-Compose is in preview mode (since 2018), and a lot of the options are actually not supported. I tried mounting the storage to a single container app and used ssh to connect to it, and the file is exactly where one would expect it to be. With a multi-container app this doesn't work. I feel like the docker-compose feature is not yet fully supported