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This assumes the pre-existence of the SNS 18 | topic, AWS Lambda function, CloudWatch Scheuduled Event Rule, and 19 | IAM permissions. 20 | -------------------------------------------------------------------------------- /lambda_function.py: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env python3.6 2 | import os 3 | import json 4 | from datetime import datetime 5 | import boto3 6 | import logging 7 | 8 | days = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'] 9 | 10 | logger = logging.getLogger() 11 | logger.setLevel(logging.INFO) 12 | 13 | def chime(sns_topic_arn, region, event_time, uuid, reference, support): 14 | chime_time = datetime.strptime(event_time, '%Y-%m-%dT%H:%M:%SZ') 15 | chime_yyyy = str(chime_time.year) 16 | chime_mm = str(chime_time.month).zfill(2) 17 | chime_dd = str(chime_time.day).zfill(2) 18 | chime_hh = str(chime_time.hour).zfill(2) 19 | chime_mi = str(chime_time.minute).zfill(2) 20 | chime_ss = str(chime_time.second).zfill(2) 21 | chime_day = days[chime_time.weekday()] 22 | timestamp = (chime_yyyy + '-' + chime_mm + '-' + chime_dd + 23 | ' ' + chime_hh + ':' + chime_mi + ' UTC') 24 | subject = "[Unreliable Town Clock] chime: " + timestamp 25 | message = { 26 | 'source': 'townclock.chime', 27 | 'type': 'chime', 28 | 'version': '3.0', 29 | 'timestamp': timestamp, 30 | 'year': chime_yyyy, 31 | 'month': chime_mm, 32 | 'day': chime_dd, 33 | 'hour': chime_hh, 34 | 'minute': chime_mi, 35 | 'day_of_week': chime_day, 36 | 'unique_id': uuid, 37 | 'region': region, 38 | 'sns_topic_arn': sns_topic_arn, 39 | 'reference': reference, 40 | 'support': support, 41 | 'disclaimer': 'UNRELIABLE SERVICE' 42 | } 43 | message_payload = json.dumps(message, indent=2) 44 | logger.info('message: {}'.format(message_payload)) 45 | 46 | client = boto3.client('sns') 47 | response = client.publish( 48 | TargetArn=sns_topic_arn, 49 | Subject=subject, 50 | MessageStructure='string', 51 | Message=message_payload 52 | ) 53 | logger.info('sns publish response: {}'.format(json.dumps(response), indent=2)) 54 | 55 | def lambda_handler(event, context): 56 | logger.info('event: {}'.format(json.dumps(event))) 57 | chime(os.environ['sns_topic_arn'], 58 | event['region'], 59 | event['time'], 60 | event['id'], 61 | os.environ['reference'], 62 | os.environ['support'] 63 | ) 64 | 65 | if __name__ == "__main__": 66 | os.environ['sns_topic_arn'] = 'arn:aws:sns:us-east-1:522480313337:townclock-TEST-20151008a' 67 | os.environ['support'] = 'YourNameHere ' 68 | os.environ['reference'] = 'http://townclock.io' 69 | lambda_handler({ 70 | "version": "0", 71 | "id": "d9bdd3a1-0fa5-499c-9eb7-e0097e03b54b", 72 | "detail-type": "Scheduled Event", 73 | "source": "aws.events", 74 | "account": "123456789012", 75 | "time": "2017-05-13T05:15:00Z", 76 | "region": "us-east-1", 77 | "resources": [ 78 | "arn:aws:events:us-east-1:123456789012:rule/my-scheduled-rule" 79 | ], 80 | "detail": {} 81 | }, None) 82 | --------------------------------------------------------------------------------