Flask how can I use after_request to print out all responses and not break swagger-ui?

Question

Setup:

• connexion[swagger-ui]==2.13.0
• Flask==2.2.5

I am using connexion (Not Flask directly), to set up my app and host swagger. I want to print out every request and response payload to console before sending it.

I tried using these after building my connexion app

# Add pre payload printer to app
connex_app.app.before_request(print_request(config))
connex_app.app.after_request(print_response(config))

Here are those functions

def print_request(config):
    '''
    Print out requests received, or response sent
    '''
    def request_logger():
        if request.method not in ('GET'):
            if config.myproject.logging.myproject.pretty_print.request_payloads:
                logger.debug(f"Request received, Body: {request.get_data(as_text=True)}")
            else:
                data = request.get_json() if request.is_json else {}
                flat_json = json.dumps(data, separators=(',', ':'))
                logger.debug(f"Request received, Body: {flat_json}")
        else:
            logger.debug("Request received")

    return request_logger

def print_response(config):
    '''
    Print out requests received, or response sent
    '''
    def response_logger(response):
        # Ensure you have access to the correct response object here, this might need to be passed explicitly
        if config.myproject.logging.myproject.pretty_print.response_payloads:
            logger.debug(f"Response sent, Body: {response.get_data(as_text=False)}")
        else:
            # This section might need adjustment based on how you're handling response data
            data = response.get_json() if response.is_json else {}
            flat_json = json.dumps(data, separators=(',', ':'))
            logger.debug(f"Response sent, Body: {flat_json}")
        return response

    return response_logger

The problem is this line

logger.debug(f"Response sent, Body: {response.get_data(as_text=False)}")

For some reason it tries to redirect swagger-ui requests and responses to its interface, which then breaks the swager-ui. This is very odd to me, as I did not have this issue yesterday. I did have connexion dependency set to 2.*, and I have no idea what version was being used before. I do not have time to change all my code to use connexion 3.0, so that is not an option right now. Also I had to set Flask==2.2.5 because of a JSONEncoding problem with newer versions.

Has anyone else ran into this before? Am I printing responses properly? is there a better way to do it?

This just feels like a dependency issue going on and I am not sure how to fix it...

Answer 1

I gave up trying to get this to work without breaking swagger. I disabled using this method, and ended up creating my own decorator, and attached to every route path that I wanted to print the response for. Its not a great workaround but it meets my needs.