On Running a docker container, It is exiting automatically

git repo : https://github.com/samAd0san/two-tier-flask-app.git

I have used the Dockerfile to build an image, then proceeded by running a flask app container.

docker run -d -p 5000:5000 --network=twotier 
           -e MYSQL_HOST=mysql 
           -e MYSQL_USER=admin 
           -e MYSQL_PASSWORD=admin 
           -e MYSQL_DB=myDb 
           --name=flaskapp flaskapp:latest

The problem occurs when I launch this command:

docker ps -a
2860157851d9   
flaskapp:latest   
"python app.py"

      5 minutes ago   Exited (1) 5 minutes ago

flaskapp

The container should run on executing the command so that I can deploy the flask app on the container and it is connected with mysql container.

Ultimately I'm not able to access the application.