How to pass event parameters to AWS Lambda function using API Gateway?

Question

I have an AWS Lambda function written in python that is initiated by a Zapier trigger that I set up. As I pass some input parameters to the function in the Zapier trigger, I can access to the input parameters in my python code by using variables such as event[parameter1] . It perfectly works.

I'm trying to access the same Lambda function in Airtable Scripting environment. In order to do it, I set up an API Gateway trigger for the Lambda function, but I can't figure out how to pass input parameters in the vanilla JS environment. Below is the code that I have, which gives me "Internal Server Error" .

Your help would be definitely appreciated!

const awsUrl = "https://random-id.execute-api.us-west-2.amazonaws.com/default/lambda-function";
let event = {
    "queryStringParameters": {
        "gdrive_folder_id": consFolderId,
        "invitee_email": email
    }
};

let response = await fetch(awsUrl, {
    method: "POST",
    body: JSON.stringify(event),
    headers: {
        "Content-Type": "application/json",
    }
});
console.log(await response.json());

[Edited] Plus, here's the code of the Lambda function and the latest cloudwatch log after a successful execution invoked by Zapier. It's a simple code that automates Google Drive folder sharing based on 2 inputs. (Folder ID + email address) Please bear with me for the poor code quality!

from __future__ import print_function
from googleapiclient.discovery import build
from google.oauth2 import service_account

SCOPES = ['https://www.googleapis.com/auth/drive']
SERVICE_ACCOUNT_FILE = 'service.json'


def lambda_handler(event, context):
    """Shows basic usage of the Drive v3 API.
    Prints the names and ids of the first 10 files the user has access to.
    """
    # 2-legged OAuth from Google service account
    creds = service_account.Credentials.from_service_account_file(
        SERVICE_ACCOUNT_FILE, scopes=SCOPES)

    drive_service = build('drive', 'v3', credentials=creds)

    # change multiple permissions with batch requests
    folder_id = event['gdrive_folder_id']
    email_address = event['invitee_email']

    def callback(request_id, response, exception):
        if exception:
            # Handle error
            print(exception)
        else:
            print("Permission Id: {}".format(response.get('id')))

    batch = drive_service.new_batch_http_request(callback=callback)
    user_permission = {
        'type': 'user',
        'role': 'writer',
        'emailAddress': email_address
    }
    batch.add(drive_service.permissions().create(
            fileId=folder_id,
            body=user_permission,
            fields='id',
    ))
    batch.execute()

Answer 1

I'm not a Python expert and I don't know how you've setup your API Gateway integration with Lambda but I believe your code can have two issues:

1.) Internal Server Error as a response from the API Gateway endpoint also often refers to a problem in the integration between the API Gateway and your Lambda function. In this case here I can not see where you are returning a valid response back to the API Gateway. In your example the return value of batch.execute() is probably returned, right? However, by default the API Gateway expects an object that contains a statusCode and body and optionally headers . You can have a look at the AWS Lambda handler documentation for Python and their examples. Also this documentation page might be of interest for you.

2.) In your function you are accessing the event data like event['gdrive_folder_id'] . However, I can not see that you are parsing the event data somewhere. Are you using a custom integration between your API Gateway? Because in case of a proxy integration the API Gateway sends an object that has a body field and from there you'd need to read the HTTP body. See examples on this documentation page .

Here are some more thing you can check on your own: Have you also checked what you get when you just print the event data? Also, is the batch.execute() waiting for the batch processing or does it return anything? If so, what does it return?

One note here: You haven't told us anything about the integration between your API Gateway and your Lambda function. Since you can do some mapping between the API Gateway and AWS Lambda, it could be possible that you are converting the request and response outside of the Lambda function and hence, my suggestions above are wrong. Let me know if this is true or not and we can further investigate it.