What is the difference between docker and docker-compose
docker manages single containers
docker-compose manages multiple container applications
Dockerize a Flask, Celery, and Redis Application with Docker Compose
Learn how to install and use Docker to run a multi-service Flask, Celery and Redis application in development with Docker Compose.
How to know the reason why a docker container exits?
Others have mentioned docker logs $container_id to view the output of the application. This would always be my first thing to check.
Next, you can run a docker inspect $container_id to view details on the state.