[Lambda] e.g. API Gateway->Lambda->Slack

postSlack.py

from __future__ import print_function

import boto3
import json
import logging
import os

from base64 import b64decode
from urllib2 import Request, urlopen, URLError, HTTPError


# The base-64 encoded, encrypted key (CiphertextBlob) stored in the kmsEncryptedHookUrl environment variable
ENCRYPTED_HOOK_URL = os.environ['kmsEncryptedHookUrl']
# The Slack channel to send a message to stored in the slackChannel environment variable
SLACK_CHANNEL = os.environ['slackChannel']

HOOK_URL = "https://" + boto3.client('kms').decrypt(CiphertextBlob=b64decode(ENCRYPTED_HOOK_URL))['Plaintext']

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


def lambda_handler(event, context):
    logger.info("Event: " + str(event))

    slack_message = {
        'channel': SLACK_CHANNEL,
        'text': "%s" % (str(event))
    }

    req = Request(HOOK_URL, json.dumps(slack_message))
    try:
        response = urlopen(req)
        response.read()
        logger.info("Message posted to %s", slack_message['channel'])
    except HTTPError as e:
        logger.error("Request failed: %d %s", e.code, e.reason)
    except URLError as e:
        logger.error("Server connection failed: %s", e.reason)