Is there a way to make an Ubuntu service refresh automatically?

Question

I'm running a Flask API on an Ubuntu 20.04 server. The API pulls data from a pickled file. I've noticed that you have to restart the service for the Flask app to update with the new data from the file. Is there a way to have it pull from the file every time it receives a request?

Answer 1

What you want is to move your pickle loading code to a decorator, and then decorate the functions that need the fresh pickle with that decorator.

There's a lot of information to be found on decorators, but here's a small example:

def preload(func):
    def preload_wrapper(*args, **kwargs):
        print("put your pickle load code here.")
        return func(*args, **kwargs)
    return preload_wrapper


@preload
def im_a_http_get_function():
    print("you can see the order in which this gets executed")


# call the funciton for testing
im_a_http_get_function()

output

put your pickle load code here.
you can see the order in which this gets executed