Simple flask payload dump

I’m building an integration between two services and wanted to know what was being sent. This simple flask app allowed me to check the payload. Run this, and then open a ngrok tunnel connected to port 5000. You’ll have a live incoming webhook app!

First, let’s create a virtual environment and install Flask. After CDing into your work folder:

~ $ python3 -m venv virtualenvname
~ $ source virtualenvname/bin/activate  # for Linux & Mac
(virtualenvname) ~ $ pip3 install flask

Then, you can save this script in a .py file with a name you’d like such as

from flask import Flask, request
import pprint

app = Flask(__name__)

@app.route('/', methods=['POST']) 
def foo():
    print("incoming request headers: \n")
    print("incoming request json payload: \n")
    json_payload = request.get_json()
    return '', 200

if __name__ == "__main__":

To do this more “real” let’s open a tunnel via ngrok on port 5000. Then, from Postman or curl, you can POST to this endpoint with some json data:

~$ curl --location --request POST 'https://{ngrokSubdomain}' \
--header 'Content-Type: application/json' \
--data-raw '{"json":"data", "more":"info"}'

In the terminal where you were running the Flask app, you’ll see:

$ python3 
 * Serving Flask app "events" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 917-572-642
incoming request headers: 

Content-Type: application/json
User-Agent: PostmanRuntime/7.26.5
Accept: */*
Postman-Token: fabb1b81-fa4f-4829-bc1e-30321---
Host: {ngrokSubdomain}
Accept-Encoding: gzip, deflate, br
Content-Length: 30
X-Forwarded-Proto: https

incoming request json payload: 

{'json': 'data', 'more': 'info'}
None - - [06/Nov/2020 14:17:35] "POST / HTTP/1.1" 200 -

{'json': 'data', 'more': 'info'} is the json we sent in the POST request.