DIY: your own PaaS using Python

Talk presented during OSDC.fr 2012 (OpenWorld Forum).
Don't do that, just use an existing PaaS ;)

1. Do It Yourself: Your Own PaaS in Python whoami
2. Wuts teh PaaS ting ?
3. Dis ar teh Clown Computin U sign ? U haz providerz ?
4. Y mak ur pwn PaaS ? self-hosting ! better understanding of PaaS platforms It's fun !
5. PaaS architecture Teh devlopment workflow 1. write code 2. test code 3. commit code 4. push code 5. QA test 6. tag release (production)
6. Y U LIE ? Points 2. & 5. from previous slides are obvious lies because it looks good and it pleases managers ! Wat do u ned ? machines applicative stack DNS server orchestration framework SCM API
7. Git Ur Toolbox RDY !
8. DNS Server Bind dynamic DNS nsupdate update delete <my_app>.<my_domain> A update add <my_app>.<my_domain> 180 A <node_ip>
9. SCM git gitolite Gitolite ? SSH proxy no real user, no shell access fine-grained control access to repository
10. Applicative stack virtualenv pip WSGI ! virtualenv --no-site-packages <my_app> source bin/activate pip -r requirements.txt gunicorn <my_app>:app
11. Orchestration install/remove/update packages edit configuration files upload/download files start/stop/monitor services etc ... many choices CFEngine/Puppet/Chef/Salt/Ansible etc. Fabric !
12. Fabric Wut Wut ? Python module command-line tool: fab SSH-based Principels tasks hosts
13. I CAN HAZ ? from fabric.api import * def update(): """ update machine using yum """ with settings(hide('running', 'stdout', 'stderr', 'warnings'), warn_only=True): sudo("yum -y update") fab -H <use>@<my_node> update
14. RLY Thaz all ? Awsome ! can be used with command-line (auto-documented !) can be used in Python code Web API !
15. Web API ! REST CRUD Twisted event-based network engine Easy to create web services ! a sample CRUD application
16. a sample CRUD application import sys from twisted.internet import reactor, server, resource, http class Persona(resource.Resource): def __init__(): pass def render_GET(self, request): # request contains all parameters # you crunch it and return res return res def render_PUT(self, request): pass a sample CRUD application def render_DELETE(self, request): pass def render_POST(self, request): pass def render_UPDATE(self, request): pass if __name__ == "__main___"": root = resource.Resource() persona = Persona() root.putChild('persona', persona) reactor.listenTCP(80, server.Site(root) U no machines ?
17. U no machines ? erm ... IaaS is in da place Boto fire new cloud instances very eazy
18. very eazy import boto import boto.ec2 conn = boto.conn_ec2() reservations = conn.run_instances(**<dict_of_conf>) conn.terminate_instances(<list_of_ids>) Conclusion