lambda_function.py

import urllib3 
import json
http = urllib3.PoolManager() 
def lambda_handler(event, context): 
    url = ""    
    msg = {
        "channel": "",
        "username": "WEBHOOK_USERNAME",
        "text": event['Records'][0]['Sns']['Message'],
        "icon_emoji" : ""
    }
    encoded_msg = json.dumps(msg).encode('utf-8')
    resp = http.request('POST',url, body=encoded_msg)
    print({
        "message": event['Records'][0]['Sns']['Message'], 
        "status_code": resp.status, 
        "response": resp.data
    })