Flask API backend

Transcript

1. Flask API backend Mikhail Kashkin, Dnepr.py 2015
2. About me • Python developer, community member • Now Flask if web, most frameworks before • Twitter: @mikashkin • GitHub: @xen
3. Tutorial code
4. Few words before we start • It is ok for tutorial, but some people really try to use this approach for real life. Don’t be that guy • In real project this is terrible idea to have everything in one file • Shameless plug, I’ve done everything for you 
 https://github.com/xen/flask-project-template • Flask have all needed parts: Blueprints and Extensions
5. Flask ecosystem • pip search flask | wc -l
 830 • django - 7562, plone - 1633, zope - 838, tornado - 259 • Platforms available: WSGI, GAE, Heroku
6. …batteries (blackjack, hookers) • Flask-Script -> click.py • Flask-FlatPages • Flask-Babel • Flask-WTF • Flask-Cache • Flask-Admin • python-social • Flask-Mail • Flask-SQLAlchemy (peewee) • Flask-migrate (alembic) • Flask-Cache • Flask-restless • Flask-rq • Celery • DS connectors: RDBMS, NoSQL
7. Backend roadmap 1. Have something 2. Make/update models 3. Make/update endpoints 4. Optimize 5. Goto 2 7. PROFIT
8. [blueprint]/models.py
9. DB related commands python  db  upgrade  -­‐m  "New  box  model"   python  db  migrate
10. flask-restless https://flask-restless.readthedocs.org/en/latest/
11. Flask-Admin* * Doesn’t really needed by mobile client, but if we get it for free?
12. RESTFul API • Framework should care: • Nice URL schema, be nice for people who will use it • Versioning • Aliases • Search • Limit fields returned by API • Cache headers • JSON • HTTP_X_HTTP_METHOD_OVERRIDE • Out of the scope: • SSL • Documentation
13. RESTful Brogramming
14. Deeper, bro
16. Aliases
17. Versioning
18. Limit fields
19. Client caching
20. F**g Fast autocomplete
21. Test API like a boss http://httpie.org/ Adv
22. HTTP Method Overrides • http://flask.pocoo.org/docs/0.10/patterns/methodoverrides/ • Sometimes users are behind proxies that not support some HTTP methods. There is convenient way to support them
 
 
 
 
 
 
 

23. Throttling* • Generally bad idea, your API is not really open if you use this technics • Storing data about how much user consumed data is bottle neck for most cases • If you still need it use memcache via Flask-Cache
24. User authentication • Can be very complicated or not • If you just need to authorize user use Flask-Auth • If you need Facebook, Twitter, etc use python-social • python-social can ruin your day, or two. Not sure that integration now works. Freeze version that is working for you
25. Background tasks • Celery, fit all cases • Flask-rq (redis), if you just need quick background tasks aka defer
26. celery_run.py
27. app.py@create_celery
28. tasks.py
29. Deployment
30. Flask in clouds • Google App Engine, have MySQL instances. Be careful with regions • Heroku. You can use Postgres • AWS. Build your own server • Digital Ocean. You can use Ansible for your tasks
31. site.yml
32. Deployment $  ansible-­‐playbook  -­‐-­‐ask-­‐sudo-­‐pass  site.yml
33. https://github.com/xen/flask-project-template Questions time
34. Thank you Twitter: @mikashkin GitHub: @xen