No connection in a multicontainer docker environment - amazon-web-services

Question

I am trying to deploy an application in Docker running on 64bit Amazon Linux 2. I am using a pipeline, which publishes images to a private repository on Dockerhub. Elastic beanstalk uses docker-compose to run containers, but so far I've had no success in accessing the application. I am not using a dockerrun.aws.json file, as v.3 does not support any container configuration, and as far as I know, it's not needed for docker compose.
My docker-compose file contains several services, one of which is a RabbitMQ message broker.
version: '3.9'
services:
Some.API:
image: ...
container_name: some-api
networks:
- my-network
ports:
- "9002:80"
Another.API:
image: ...
container_name: another-api
networks:
- my-network
ports:
- "9003:80"
rabbitmQ:
image: rabbitmq:3-management-alpine
container_name: rabbit-mq
labels:
NAME: rabbitmq
volumes:
- ./rabbitconfig/rabbitmq-isolated.conf:/etc/rabbitmq/rabbitmq.config
networks:
- my-network
ports:
- "4369:4369"
- "5671:5671"
- "5672:5672"
- "25672:25672"
- "15671:15671"
- "15672:15672"
front-end:
image: ...
container_name: front-end
networks:
- my-network
ports:
- "9001:80"
networks:
my-network:
driver: bridge
Once the current version of the application is successfuly deployed to Beanstalk, I see that there is no successful communication in the bridge network.
In the eb-stdouterr.log I see that there are errors while establishing connection between the apis and the message broker:
RabbitMQ.Client.Exceptions.BrokerUnreachableException: None of the specified endpoints were reachable.
The APIs are .NET Core applications, which use the Beanstalk's environment variables to determine the name of the broker service. In the Configuration/Software/Environment properties section there is a following entry:
RABBIT_HOSTNAME | rabbitmq
which should ensure that the services use a proper host name.
Yet, I get exceptions. Any advice?

Answer 1

It turned out that I needed to reference the automatically generated .env file in docker-compose.yml like so:
front-end:
image: ...
container_name: front-end
networks:
- my-network
ports:
- "9001:80"
env_file: <--- these
- .env <--- 2 lines
for each service. Only after doing this the Environment properties from AWS Beanstalk were passed to the containers.