Gracefull shutdown doesn't work for processes started from user data script on ec2

Question

Steps to reproduce
1. I started an EC2 instance with a user data script.
2. This script initiates my application.
3. A graceful shutdown is implemented in the application (an HTTP request is sent upon receiving SIGTERM).
4. I stop/reboot/terminate the EC2 instance.
Expected:
The application receives a SIGTERM signal and makes a request.
Actual:
The application does not receive any SIGTERM signal.

It seems like processes started from the user data script do not receive a SIGTERM signal on system shutdown.

What I've tried:
1. Starting the process in the foreground (python3 /app.py).
2. Starting the process in the background (python3 /app.py &).
3. Starting the process in the background with nohup (nohup python3 /app.py > /dev/null 2>&1 &).
None of these methods work.

What worked:
1. Starting the process in the background via SSH (ssh  'nohup python3 /app.py > /dev/null 2>&1 &').

Answer

I think you will need to have your application running in a daemon mode.. Then you will need to place a K Script in the RC3.d folder so that when the instance recieves a SIGHUP, it can stop the application

OR/AND

I would have S script in RC3.d to start your application too on boot up which executes your  'nohup python3 /app.py > /dev/null 2>&1 &'

Gracefull shutdown doesn't work for processes started from user data script on ec2

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