Lambda trigger to signOut users using accessToken and global_sign_out API

signOut.py

"""This is an function to signOut users.

Usage::
    Just create an resource and a method on the API Gateway, 
    integrate the request with this lambda function via console, and test it;

    json used to test;

    {
      "access_token":"something"
    }

"""
from __future__ import print_function
import boto3
import botocore.exceptions
import json
import logging

USER_POOL_ID = 'us-east-2_blah-blah-blah'
CLIENT_ID = 'blah-blah-blah'
CLIENT_SECRET = 'blah-blah-blah-really-long-string'

client = None

logger = logging.getLogger()
logger.setLevel(logging.INFO)

def initiate_logout(accessToken):
    try:
        resp = client.global_sign_out(
            AccessToken=accessToken
        )
    except client.exceptions.NotAuthorizedException as e:
        return None, "Unauthorized"
    except client.exceptions.UserNotFoundException as e:
        return None, "Unauthorized"
    except Exception as e:
        #print(e)
        logger.error(e)
        return None, "Unknown error"
    return resp, None

def lambda_handler(event, context):
    global client
    if client == None:
        client = boto3.client('cognito-idp')

    print(event)
    body = event
    access_token = body['access_token']
    
    resp, msg = initiate_logout(access_token)
    if msg != None:
        # return {'status': 'fail', 'msg': msg}
        logger.info('failed to logout with accessToken={}'.format(access_token))
        raise Exception(msg)

    logger.info('successfull logout with accessToken={}'.format(access_token))
    return {'message': 'Usuario deslogado com sucesso'}