Multiple Rails Application docker up not working - ruby-on-rails

Question

I have two Rails 6 application and I am trying to deploy in aws ec2 instance with different port 8080 and 8081 but when I trying to run docker-compose up -d it start one rails application successfully and if I tries to run docker-compose up -d for second application, It make first application down and make another application up on particular Port
Below is my docker configuration for two applications.
Application 1
version: "3.4"
services:
app:
image: "dockerhub_repo/a_api:${TAG}"
# build:
# context: .
# dockerfile: Dockerfile
container_name: a_api_container
depends_on:
- database
- redis
- sidekiq
ports:
- "8080:8080"
volumes:
- .:/app
env_file: .env
environment:
RAILS_ENV: staging
database:
image: postgres:12.1
container_name: a_database_container
restart: always
volumes:
- db_data:/var/lib/postgresql/data
- ./init.sql:/docker-entrypoint-initdb.d/init.sql
sidekiq:
image: "dockerhub_repo/a_api:${STAG}"
container_name: a_sidekiq_container
environment:
RAILS_ENV: staging
env_file: .env
depends_on:
- redis
volumes:
- ".:/app"
redis:
image: redis:4.0-alpine
container_name: a_redis_container
volumes:
- "redis:/data"
volumes:
redis:
db_data:
Application 2
version: "3.4"
services:
app:
image: "dockerhub_repo/b_api:${PPTAG}"
build:
context: .
dockerfile: Dockerfile
container_name: b_api
depends_on:
- database
- redis
ports:
- "8081:8081"
volumes:
- .:/app
env_file: .env
environment:
RAILS_ENV: development
database:
image: postgres:12.1
container_name: pp_database
restart: always
volumes:
- db_data:/var/lib/postgresql/data
- ./init.sql:/docker-entrypoint-initdb.d/init.sql
redis:
image: redis:4.0-alpine
container_name: pp_redis
volumes:
db_data:
This Configuration works very well in local machine. It start both application in local on different port but it has some issue on aws ec2. I am not sure is any thing wrong in configuration?

Answer 1

Compose has the notion of a project name. If you add or delete containers from a docker-compose.yml file, it looks for existing containers that are labeled with the project name to figure out what needs to change. The project name is also included in the Docker names of containers, networks, and volumes.
You can configure the project name with the COMPOSE_PROJECT_NAME environment variable or the docker-compose -p option. If you don't configure it, it defaults to the base name of the current directory.
You clarify in a comment that the two docker-compose.yml files are in directories app1/backend and app2/backend. Since the base name of those directories are both backend, they have the same project name; so if you run docker-compose up in the app2/backend directory, it finds the existing containers for the backend project, sees they don't match what's in the docker-compose.yml file, and deletes them (even though you as the operator think they belong to the other project).
There are a couple of ways to get around this:
Rename one or the other directory; maybe move the docker-compose.yml files up to the top-level app1 and app2 directories.
In one or both directories, create a .env file that sets COMPOSE_PROJECT_NAME=app1. (Note that file is checked in the current directory, not necessarily the directory that contains the docker-compose.yml file.)
Set and change an environment variable export COMPOSE_PROJECT_NAME=app1.
Consistently use an option docker-compose -p app1 ... with all Compose commands.