An introduction to Google App Engine PAAS using Python

1. Infinite Scale
Introduction to Google App Engine

3. There are only 10 types of people
in the world: those who understand
binary, and those who don’t

4. There are only 10 types of people
in the world: those who understand
binary, and those who don’t
If you smiled, chances are you’ll understand this
presentation, if not, at least you’ll know this stuff exists

5. Google Cloud Platform

6. Google App Engine
• Platform as a Service
• Run applications on Google’s infrastructure
• Used by millions
• Best Buy / Coca Cola / Ubisoft / Sony

7. Google App Engine
• Build and deploy
• No worrying about servers or load balancers
• Auto scale to 7 billion requests per day
• Java / Python / PHP / Go

8. GAE Python Runtime Environment
• App Engine executes Python app code using
an interpreter in a "sandboxed" environment
• The interpreter can run any pure Python code
• The "sandbox" environment isolates your app
for service and security; an application
cannot:
– Write to the filesystem
– Respond slowly
– Make other kinds of system calls

9. GAE Python Runtime Environment
• GAE Request Headers
– Sanitized for security
– Additional headers: country, region, city, latlong
• GAE Responses
– All output data is sent, does not support sending data
to the browser before the handler returns
– Additional headers when accessing the site as
administrator:
• Estimate of what 1,000 similar requests would cost
• Resources used by the request, including server-side time
• GAE automatically uses the SPDY protocol

10. Google App Engine Python Tutorial
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

11. Google App Engine Python Tutorial
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

12. GAE Tutorial Hello, Universe!
• Configuration file: app.yaml
– YAML: recursive acronym for
“YAML Ain’t Markup Language”
– YAML is a human friendly data serialization
standard for all programming languages
• Python script: hellouniverse.py
<CODE/>

13. Google App Engine Python Tutorial
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

14. GAE Tutorial Frameworks
• GAE supports any framework written in pure
Python that speaks WSGI
– Django, CherryPy, Pylons, web.py, web2py, etc.
• WSGI – Web Server Gateway Interface
– Interface between web servers and web
applications or frameworks for Python
• Webapp2
– App Engine includes a simple web application
framework, called webapp2

15. GAE Tutorial Frameworks
• A webapp2 application has two parts
– one or more RequestHandler classes that process
requests and build responses
– a WSGIApplication instance that routes incoming
requests to handlers based on the URL

16. Google App Engine Python Tutorial
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

17. GAE Tutorial Users
• GAE provides several useful services based on
Google infrastructure
• Users service lets your application integrate
with Google user accounts
• With the Users service, your users can use the
Google accounts they already have to sign in
to your application
<CODE/>

18. Google App Engine Forms
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

19. GAE Tutorial Forms
• The webapp2 framework makes processing
form data easy
– Define handlers to send form data
– Define classes or methods to process data
<CODE/>

20. Google App Engine Datastore
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

21. GAE Tutorial Datastore
• App Engine's data repository, the High
Replication Datastore (HRD), replicates data
across multiple datacenters
• Data is written in Entities
• The entities form a hierarchically-structured
space similar to a directory structure
<CODE/>

22. Google App Engine Templates
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

23. GAE Tutorial Templates
• With a templating system the HTML is kept in
a separate file with special syntax
• There are many templating systems for
Python: EZT, Cheetah, ClearSilver, Quixote,
Django, Jinja2, etc.
• App Engine includes the Django and Jinja2
templating engines
<CODE/>

24. Google App Engine Assets
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

25. GAE Tutorial Assets
• GAE does not serve files directly out of your
application's source directory
• There are many cases where you want to
serve static files directly to the web browser:
Images, CSS stylesheets, JavaScript code,
movies, Flash animations, etc.
• App Engine can serve specific files without you
having to code your own handler
<CODE/>

26. Google App Engine Tests
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

27. GAE Tutorial Tests
• Instead of writing tests after you finish
developing your application, consider writing
the tests as you go
• App Engine provides testing utilities that use
local implementations of datastore and other
App Engine services, by using service stubs
(local service simulators)
<CODE/>

28. Google App Engine Deployment
1. Hello, Universe!
2. Frameworks
3. Users
4. Forms
5. Datastore
6. Templates
7. Assets
8. Tests
9. Deployment

29. GAE Tutorial Deployment
• Use appcfg.py script or GAE Launcher
• Each project can have one Release Pipeline:
– Building the application
– Running unit tests (optional)
– Deploying the application to App Engine
– Sending notifications upon completion (optional)
• Trigger the Release Pipeline by pushing the
source to the master branch
of your Cloud Repository <EXAMPLE/>

30. Resources:
• Google Cloud Platform
https://cloud.google.com/
• Google App Engine Docs
https://cloud.google.com/appengine/docs
• GAE Developers Console
https://console.developers.google.com
• This tutorial is based on the official Python Getting Started guide
from Google App Engine, created by the App Engine team and
licensed under the Creative Commons Attribution 3.0 License
Thank You!