Just try to receive a webhook in ngrok and python

tl;dr

• Sometimes you need a token sent by webhook to create a bot etc.
• Webhook requires a server to publish to the outside, but try to receive the webhook as easily as possible
• Using Python, it was easy to create a server that not only listens but also returns 200 OK.

Subject

• Based on LINE's Messaging API webhook.
• This is JSON format data sent by POST.
• This time, 200 OK is returned so that the LINE side can declare that the webhook can be received.

flow

1. Create a server that returns 200 OK no matter what you receive in Python
2. Create an environment where you can receive access from the outside with ngrok
3. Take a look at the contents of the webhook you received with the Inspect tool that comes with ngrok

Create a server that returns 200 OK no matter what you receive in Python

• I want to change the behavior according to GET and POST, so I use BaseHTTPRequestHandler of http.server.

  • https://docs.python.org/ja/3/library/http.server.html

• This time, listen on 80 port, and when POST is received, return only 200 OK for the time being.

import http.server
import socketserver
import json

class MyHandler(http.server.BaseHTTPRequestHandler):
    def do_POST(self):
        self.send_response(200)
        self.end_headers()

with socketserver.TCPServer(("", 80), MyHandler) as httpd:
    httpd.serve_forever()

• Please execute it after creating it.

serving at port 80

Is displayed, it is OK.

Create an environment where you can receive access from the outside with ngrok

• ngrok is a service that allows you to easily publish your local host to the Internet.
  • https://ngrok.com/
  • https://qiita.com/mininobu/items/b45dbc70faedf30f484e
• After signing up, the screen below will appear, so follow the guide.

Guide

• You can register authtoken or start http tunnel at the command prompt, but it is also convenient to use a bat file.
• Unzip the downloaded zip and you will find ngrok.exe.
• Create a file with the following contents in the same location.

auth.bat

ngrok authtoken 1UFVG5sdtzGXXXXXXXXX

80listen.bat

ngrok http 80

• Double-click each to execute.
• auth.bat closes instantly.
• 80listen.bat should look like this:

ngrok

• The address ending with ngrok.io in the Forwarding column displayed in this window is your address.

Take a look at the contents of the webhook you received with the Inspect tool that comes with ngrok

• If you try POSTing to this ngrok.io address from the outside
• The ngrok screen shows that POST has arrived at /

ngrok

• The contents of the request are displayed on the screen of the server made by python.

• You can see it more clearly by accessing http: // localhost: 4040 / inspect / http with a browser.

• https://ngrok.com/docs#getting-started-inspect

inspect screen example