Lambda function (python3.7) to send SNS message to Slack

sns_to_slack.py

import urllib.request
import json
import os

# https://docs.aws.amazon.com/ja_jp/lambda/latest/dg/with-sns.html
def lambda_handler(event, context):
    req = urllib.request.Request(
        os.environ["SLACK_WEBHOOK_URL"],
        json.dumps({
            "text": event["Records"][0]["Sns"]["Subject"],
            "attachments": [{
                "text": event["Records"][0]["Sns"]["Message"],
            }]
        }).encode(),
        {"Content-Type": "application/json"},
    )
    with urllib.request.urlopen(req) as res:
        status = res.status
        body = res.read().decode("utf-8")

    return {
        'statusCode': status,
        'body': json.dumps(body),
    }

# print(lambda_handler({"Records": [{"Sns": {"Subject": "subject", "Message": "message"}}]}, 0))