This document provides an overview of using Amazon Elastic Beanstalk (EB) as a platform as a service (PAAS) for scalable web applications. It discusses how EB abstracts away the complexity of infrastructure management by automatically handling tasks like provisioning servers, load balancing, and scaling. The document demonstrates setting up a sample Flask application on EB, including creating environments, deploying code, configuring health checks and auto scaling. It also shows how to use Amazon Simple Queue Service (SQS) with EB for asynchronous processing by creating a worker environment that receives messages from a queue.

1. ì Scalable Web applications with Elastic
Beanstalk as your PAAS: a primer
César Cárdenas Desales

2. Web development without PAAS
ì Deploying a web app in the late 90’s
ì Buy a server (weeks)
ì Install the OS (days, hours)
ì Install updates (hours)
ì Configure Apache (days, weeks)
ì Configure Perl CGI, mod_python or similar
ì Scaling
ì Buy larger server (snowflake servers)
ì Rinse and repeat
ì Or go for J2EE’s $$$ app servers

3. Why does PAAS make me excited?
ì I’m an aging developer

4. What is PAAS?
ì Different approach to (Web) Development
ì PlaSorm As A Service
ì “allows to develop, run, and manage applicaUons
without the complexity of building and maintaining the
infrastructure”

5. What is PAAS?
via hXp://www.thecloudinfographic.com/2012/03/02/saas-paas-and-iaas-what-are-they.html

6. Examples of PAAS

7. What is AWS Elastic Beanstalk?
ì Amazon’s PAAS offer
ì OrchestraUon plaSorm
ì EC2, S3, SNS, CloudWatch,
AutoScaling, ELB
ì More abstracUon vs. EC2: box
running the bare OS
ì Beanstalk: AbstracUon layer on top

8. Sample project structure

9. application.py
from flask import Flask!
application = Flask(__name__)!
!
!
@application.route('/hello')!
def hello_world():!
return 'Hello, World!'!
!
if __name__ == "__main__":!
application.debug = True!
application.run()!

10. requirements.txt
awsebcli==3.10.1!
boto3==1.4.4!
Flask==0.12.2!
awscli==1.11.90!
!

11. Virtual environment
$ mkvirtualenv hello-ebs!
$ workon hello-ebs!
$ pip install -r requirements.txt!
$ python application.py !

12. Application running locally
(hello-ebs) $ python application.py !

13. Elastic Beanstalk boilerplate
ì Create EBS application!
$ eb init --platform python3.4 hello-ebs!
Application: hello-ebs
Environment:!
hello-ebs-env
Environment:!
hello-sqs-env

14. Supported technologies
ì Docker on
ì Apache
ì Nginx
ì Passenger
ì IIS

15. Elastic Beanstalk boilerplate
ì Create EBS application!
$ eb init --platform python3.4 hello-ebs!
ì Configure SSH access!
$ eb init!
ì Create environment !
$ eb create hello-ebs-env!
ì Deploy changes!
$ eb deploy hello-ebs-env!

17. A new app at the Dashboard

19. Deployed app

20. Scaling with Elastic Load Balancing

21. Auto Scaling

22. EC2 instances

23. Saved Configurations

25. Meet .ebextensions/

26. 00-set-timezone.config
commands:!
set_time_zone:!
command: ln -f -s /usr/share/zoneinfo/Europe/Zurich /etc/
localtime!

27. When to scale?
option_settings:!
- namespace:
aws:autoscaling:scheduledaction!
resource_name: FRNightlyPeak!
option_name: MinSize!
value: 3!
…!
- namespace:
aws:autoscaling:scheduledaction!
resource_name: FRNightlyPeak!
option_name: Recurrence!
value: "40 21 * * *"!

28. What to scale?
option_settings:!
"aws:autoscaling:launchconfiguration":!
InstanceType: 't2.micro'!

29. Health checks
option_settings:!
"aws:elasticbeanstalk:application":!
"Application Healthcheck URL": /health!
!
@application.route('/health', methods=['POST', 'GET'])!
def health():!
return 'OK’!
!

30. Health checks

31. Monitoring & Alarms

32. Broken health check

33. Environment Configuration
@application.route('/hello')!
def hello_world():!
lang = os.getenv('SITE_LANG', 'EN')!
!
if lang == 'DE':!
return ’Hallo, Welt!’!
!
return 'Hello, World!'!

34. Environment Configuration

35. Set Env Variables in the CLI
#!/usr/bin/env bash!
!
eb setenv AWS_ACCESS_KEY_ID='foo' !
AWS_SECRET_ACCESS_KEY='bar' !
SITE_LANG='DE'!

36. Deployed app

37. Logging

38. WSGI settings
ì Flask
ì Django
ì CherryPy
ì Pyramid
ì Turbogears
ì etc…

39. Deployments

40. Platform platform updates
ì Also automated on predefined
maintenance window

41. Load Balancing
ì Includes session sUckiness

42. ì
Part II Asynchronous processing: SQS

43. Part II Asynchronous processing: SQS
ì Amazon Simple Queue Service
ì For component decoupling
ì Think of SQS as a daemon

44. SQS Messages are POSTs to Workers
ì Needs a worker
environment
ì Queue feeds workers by
sending an HTTP POST
request

45. Worker environments
ì New worker environment
$ eb create --tier worker hello-sqs-env!
ì No direct contact with web end point i.e. no URL
ì A queue is auto-generated

46. Same app, +1 environment

47. Creating a queue

48. Queue configuration

49. Worker project structure

50. The worker
option_settings:!
"aws:elasticbeanstalk:sqsd":!
HttpPath: '/download_the_internet'!
WorkerQueueURL: 'hXps://sqs.eu-west-1.amazonaws.com/
263155591784/hello-sqs-queue'!

51. The worker
from flask import Flask, request!
!
application = Flask(__name__)!
!
@application.route('/download_the_internet', methods=['POST'])!
def download_the_internet():!
content = request.get_data()!
logger.debug('content: %s', content)!
!
return "I've downloaded the Internet"!

52. Send a message

53. Send a message

54. The logs
"POST /download_the_internet HTTP/1.1" 200 28
"-" "aws-sqsd/2.3”!
DEBUG:_mod_wsgi_c43d580a63001a918a0ca7939113f619:c
ontent: b'Foobar'!

55. Send messages with boto3
@application.route('/send_message/<name>')!
def send_message(name='friend'):!
sqs = boto3.resource('sqs', region_name='eu-west-1',!
aws_access_key_id=os.getenv('AWS_ACCESS_KEY_ID'),!
aws_secret_access_key=os.getenv('AWS_SECRET_ACCESS_KEY’))!
!
queue = sqs.get_queue_by_name(QueueName='hello-sqs-queue')!
!
response = queue.send_message(MessageBody=name)!
!
return (!
‘<p>Message sent: %s!</p>n Response: %s’!
) % (name, response)!

56. Send an SQS message

57. Why does PAAS make me excited?
ì I’m and old developer
ì PotenUally unlimited scaling
ì CompuUng resources are disposable
ì Low level maintenance is abstracted out
ì IT assets are programmable

58. Thanks!