├── requirements.txt ├── .gitignore ├── .chalice ├── config.json └── policy.json ├── README.md ├── Makefile ├── app.py └── LICENSE /requirements.txt: -------------------------------------------------------------------------------- 1 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | .virtualenv 2 | .chalice/deployments/ 3 | .chalice/venv/ 4 | .chalice/deployed.json 5 | __pycache__ 6 | -------------------------------------------------------------------------------- /.chalice/config.json: -------------------------------------------------------------------------------- 1 | { 2 | "version": "2.0", 3 | "app_name": "timercheck", 4 | "api_gateway_stage": "api", 5 | "autogen_policy": false, 6 | "iam_role_file": "policy.json", 7 | "environment_variables": { 8 | "table": "timer" 9 | } 10 | } 11 | -------------------------------------------------------------------------------- /.chalice/policy.json: -------------------------------------------------------------------------------- 1 | { 2 | "Version": "2012-10-17", 3 | "Statement": [ 4 | { 5 | "Effect": "Allow", 6 | "Action": [ 7 | "logs:CreateLogGroup", 8 | "logs:CreateLogStream", 9 | "logs:PutLogEvents" 10 | ], 11 | "Resource": "arn:aws:logs:*:*:*" 12 | }, 13 | { 14 | "Effect": "Allow", 15 | "Action": [ 16 | "dynamodb:DeleteItem", 17 | "dynamodb:GetItem", 18 | "dynamodb:PutItem", 19 | "dynamodb:Query", 20 | "dynamodb:Scan", 21 | "dynamodb:UpdateItem" 22 | ], 23 | "Resource": "*" 24 | } 25 | ] 26 | } -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # TimerCheck.io 2 | 3 | This repository contains an AWS Lambda function that powers the web 4 | service API behind TimerCheck.io 5 | 6 | For more information about what the service does and how to use it, 7 | please read the following article: 8 | 9 | > TimerCheck.io - Countdown Timer Microservice 10 | 11 | > https://alestic.com/2015/07/timercheck-scheduled-events-monitoring/ 12 | 13 | The following commands work on Ubuntu 17.04 Zesty: 14 | 15 | Install prerequisites: 16 | 17 | make setup 18 | 19 | Deploy to AWS account: 20 | 21 | make deploy 22 | 23 | Show AWS Lambda function logs 24 | 25 | make logs 26 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | 2 | SHELL=/bin/bash 3 | VIRTUALENV=.virtualenv 4 | STAGE=dev 5 | 6 | help: ## Show help text 7 | @grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf " %-10s %s\n", $$1, $$2}' 8 | 9 | $(VIRTUALENV)/bin/activate: 10 | virtualenv --python $$(which python3.6) $(VIRTUALENV) 11 | source $(VIRTUALENV)/bin/activate; \ 12 | pip install chalice boto3 13 | 14 | virtualenv:: $(VIRTUALENV)/bin/activate 15 | 16 | setup:: ## Install prerequisites and virtualenv 17 | sudo apt-get install python3.6 18 | sudo -H pip3 install virtualenv 19 | 20 | setup:: virtualenv 21 | 22 | deploy:: virtualenv ## Deploy to AWS 23 | source $(VIRTUALENV)/bin/activate; \ 24 | chalice deploy --no-autogen-policy --stage $(STAGE) 25 | 26 | local:: ## Run on local port 27 | source $(VIRTUALENV)/bin/activate; \ 28 | chalice local 29 | 30 | logs:: ## Show AWS Lamda function logs 31 | source $(VIRTUALENV)/bin/activate; \ 32 | chalice logs --include-lambda-messages --stage $(STAGE) 33 | 34 | clean:: ## Cleanup local directory 35 | rm -rf $(VIRTUALENV) __pycache__ .chalice/{venv,deployments,deployed.json} 36 | -------------------------------------------------------------------------------- /app.py: -------------------------------------------------------------------------------- 1 | from chalice import Chalice, Response 2 | import time 3 | import boto3 4 | 5 | app = Chalice(app_name='timercheck') 6 | home_url = 'https://alestic.com/2015/07/timercheck-scheduled-events-monitoring/' 7 | table_name = 'timer' #TBD: Convert to chalice environment variable 8 | 9 | def error(status, message): 10 | return Response( 11 | status_code=status, 12 | body={'errorMessage': message}, 13 | ) 14 | 15 | def redirect(url): 16 | return Response( 17 | status_code=301, 18 | headers={'Location': url}, 19 | body='', 20 | ) 21 | 22 | def timer_table(table_name): 23 | dynamodb = boto3.resource('dynamodb') 24 | try: 25 | response = dynamodb.create_table( 26 | TableName=table_name, 27 | AttributeDefinitions=[ 28 | { 29 | 'AttributeName': 'timer', 30 | 'AttributeType': 'S' 31 | }, 32 | ], 33 | KeySchema=[ 34 | { 35 | 'AttributeName': 'timer', 36 | 'KeyType': 'HASH' 37 | } 38 | ], 39 | ProvisionedThroughput={ 40 | 'ReadCapacityUnits': 5, 41 | 'WriteCapacityUnits': 5 42 | } 43 | ) 44 | print("Created DynamoDB table: ", table_name) 45 | except Exception as e: 46 | if e.__class__.__name__ != 'ResourceInUseException': 47 | print('ERROR creating table "%s": %s' % (table_name, e)) 48 | return dynamodb.Table(table_name) 49 | 50 | def timercheck(timer, count): 51 | try: 52 | now = int(time.time()) 53 | results = { 54 | 'timer': timer, 55 | 'request_id': app.current_request.context['requestId'], 56 | 'status': 'ok', 57 | 'now': now, 58 | 'message': 'Timer still running', 59 | } 60 | get_response = table.get_item(Key={'timer': timer}) 61 | if (not 'Item' in get_response or 62 | not 'start_time' in get_response['Item']): 63 | if count is None: 64 | return error(404, '404: timer has never been set') 65 | else: 66 | item = get_response['Item'] 67 | results['start_time'] = item['start_time'] 68 | results['start_seconds'] = item['start_seconds'] 69 | results['seconds_elapsed'] = now - item['start_time'] 70 | results['seconds_remaining'] = (item['start_seconds'] - 71 | (now - item['start_time'])) 72 | if count is None: 73 | if results['seconds_remaining'] <= 0: 74 | return error(504, 'timer timed out') 75 | else: 76 | put_response = table.put_item( 77 | Item={ 78 | 'timer': timer, 79 | "start_time": now, 80 | "start_seconds": int(count) 81 | } 82 | ) 83 | results['message'] = "Timer countdown updated" 84 | results['new_start_time'] = now 85 | results['new_start_seconds'] = int(count) 86 | return results 87 | except Exception as e: 88 | print("Unexpected Error: %s" % e) 89 | return error(500, '500: server error') 90 | 91 | @app.route('/') 92 | def index(): 93 | return redirect(home_url) 94 | 95 | @app.route('/{timer}') 96 | def get_timer(timer): 97 | return timercheck(timer, None) 98 | 99 | @app.route('/{timer}/{count}') 100 | def set_timer(timer, count): 101 | return timercheck(timer, count) 102 | 103 | @app.route('/introspect') 104 | def introspect(): 105 | return app.current_request.to_dict() 106 | 107 | table = timer_table(table_name) 108 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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