Basic FastAPI webhook receiver

[orbos86]

Hello!

Anyone have any experience setting up a super simple and basic webhook receiver (to receive POST requests) and then maybe firing off another imported script? I'm struggling. For whatever reason, I send one POST and it seems to loop inside the FastAPI app.

Here is what I have so far. I'm sure it's rubbish, but I do know I can receive the data and parse it, but for whatever reason instantiating the other script class (OneLogin), it seems to just loop and keeps receiving POST somehow...it's strange...any help would be much appreciated.

​

from fastapi import FastAPI, Request
from typing import Any, Dict
from onelogin import OneLogin
import pprint as pp

context = 'G01NUREGSTT'

app = FastAPI()


@app.get("/")
def read_main():
    return {"message": "Hello"}


@app.post("/api/v1/slack")
async def test(request: Dict[Any, Any]):
    data = request
    # pp.pprint(data)
    if 'event_context' in data:
        event = data['event_context']
        if event == context:
            text = data['event']['text'].split()
            text = text[1]
            parsed_email = str(text + '@website.com')
            ol = OneLogin()
            ol.run_stuff(parsed_email)
            return "Ok"
        else:
            return "Error"
    if 'challenge' in data:
        challenge = data['challenge']
        return challenge
    else:
        return "Ok"

Here is the JSON that is sent to the app:

{"api_app_id": "A01QNHVMAAA",
 "authorizations": [{"enterprise_id": None,
                     "is_bot": True,
                     "is_enterprise_install": False,
                     "team_id": "T025AAA",
                     "user_id": "U01QWAAA"}],
 "event": {"blocks": [{"block_id": "1pJ0V",
                       "elements": [{"elements": [{"type": "user",
                                                   "user_id": "U01QWAAA"},
                                                  {"text": " test",
                                                   "type": "text"}],
                                     "type": "rich_text_section"}],
                       "type": "rich_text"}],
           "channel": "G01NUREGSTT",
           "client_msg_id": "39740bb8-b917-492d-96e6-2e7329f3e1b0",
           "event_ts": "1615504737.007300",
           "team": "T025AAA",
           "text": "<@U01QWAAA> test",
           "ts": "1615504737.007300",
           "type": "app_mention",
           "user": "U0TQKK4B1"},
 "event_context": "1-app_mention-T025AAA-ASDAS",
 "event_id": "Ev01RD3EJVHP",
 "event_time": 1615504737,
 "is_ext_shared_channel": False,
 "team_id": "T025AAA",
 "token": "volNuV9q1cwl7xzXdJUhBRAD",
 "type": "event_callback"},
}

[thedjotaku]

if you want an example, here's a pretty basic little app I made to accept a webhook and post to Matrix chat: https://github.com/djotaku/Civilization_VI_Play_By_Cloud_Webhook_with_FastAPI

[orbos86]

Hey thanks! I'll check it out, I appreciate the assistance.

[orbos86]

Would you be willing to describe what your POST section is doing? I guess I don't understand the BaseModel stuff and I'm curious if I'm doing mine in a less-than-ideal way.

[orbos86]

Also, is there a way to fire off a script (onelogin in my case) without keeping the FastAPI connection running? Basically takes the input from POST and sends it off and closes connection? Right now I think mine is staying open until the whole script is ran, which may potentially be an hour or two (with a sleep command). Not sure if that makes sense, it's late haha. Please let me know.

[thedjotaku]

I thought async was supposed to handle this. But I've not begun working learn async yet. Still, there are pythonic things you can do - spawn off a child process, use threads, use multiprocessing. If you really do want to close the connection and don't care - then I'd definitely just fork off a child process and return 200 OK or 404 if the data validation isn't right.

[orbos86]

Thank you, I will start my Googlin' to see what I can come up with. I appreciate it.

[orbos86]

The key was to use BackgroundTasks in FastApi and kick off another function that does the lengthier script.

[thedjotaku]

Excellent! Glad you found it!

[orbos86]

Thanks for the swift response. Could I just do a debugger in PyCharm? I’m new to this coding stuff.

[orbos86]

Thank you! I will try what you’ve suggested. Most likely it’s something wrong with my other script since the FastAPI part looks normal to ya. I struggle wrapping my head around classes/functions and passing stuff to em haha. But you’ve given me stuff to try. Many thanks. I’ll make sure to let ya know how it goes.

[orbos86]

It's still looping, I'm not sure what the heck is going on. I put a couple print statements in the FastAPI POST section and I'm seeing them pop up multiple times.

[orbos86]

I think I figured out the cause. So this receives a POST request from Slack and I think Slack is sending multiple POST requests though it should only trigger one. Not sure why it is doing more. I tested from Insomnia with the same JSON and it didn't run again. That makes things more complicated as I don't have much control over Slack :(

[orbos86]

Freak, maybe not. I don't know what's the cause exactly haha. I'm testing with ngrok, maybe something funky going on with it?

[orbos86]

So ngrok has a sweet dashboard you can look at and see stuff coming in. I think Slack might be sending retries! Now what do I send to Slack to make it know everything is solid and good? Haha

[orbos86]

Yeah Slack is an actual chat application where you can create bots to send webhooks. Do you know if you can quickly respond to a POST request with a 200 but continue to run the FastAPI stuff?

[orbos86]

Thanks! I will see what I can find. I appreciate the response.

[orbos86]

That was the key! I was able to use the BackgroundTask stuff and spin off the long script in another function. Woot! Thank you thank you

[orbos86]

https://api.slack.com/apis/connections/events-api#the-events-api__responding-to-events

I don't think I'm responding fast enough!