This document discusses the continuous deployment process used by Marco Pracucci's audio platform. It deploys new code to its EC2 instances running PHP every 1.5 minutes on average through Fabric scripts. The instances are tagged and mapped to DNS names by role (web, api, worker) through a custom DNS service to address them individually or as groups. The deployment process checks for issues, warms caches, and switches to the new code in under 90 seconds, allowing for frequent deployments while maintaining a robust and scalable infrastructure.

1. Continuous Deployment
at
Marco Pracucci

2. Platform for Creating
and Sharing Audio
8 people (4 developers)
2M unique listeners / month
3.5M audio tracks created
500 reqs / sec

3. We run 80% of our
traffic on AWS
about 60 EC2 instances and 50TB on S3

4. We deploy frequently
[even on friday]
51 deploys in last 30 days

5. How we deploy
the web [php] app
in 90 seconds

6. Deploy task

7. code repository
1. ssh
fab www.deploy
EC2 instances

8. code repository
2. checkout
fab www.deploy
EC2 instances

9. code repository
Checklist
- local cache warmup
3. warmup
- db schema migrations
fab www.deploy
- check consistency
EC2 instances

10. code repository
4. switch code
fab www.deploy
everything ok?
EC2 instances

11. code repository
Checklist
- iptables --dport 80 -j DROP
- ln -sfn /var/www/new /var/www/curr
4. switch code
- clear bytecode cache
fab www.deploy
- iptables --dport 80 -j ACCEPT
EC2 instances

12. notify team on IRC
generate report
fab www.deploy

13. which instances to deploy?
we do auto-scaling, they change dinamically

14. we exploited
DNS

15. Split infrastructure into roles
EC2 instances
www1
api1
worker1
api2
www2
{
worker2
{
www3
{
api3
role: api
role: web
role: worker-web

16. Tag each instance with roles
[space separated roles for multi-role instances]

17. Map names and roles to DNS
https://github.com/airbnb/zonify
Creates Route 53 DNS entries
for all instances and roles

18. Address a single instance

19. Address instances by role

20. Easy to integrate with fabric

21. Do you remember the starting point?
Internally does
fab -R web www.deploy

22. few good reasons
Easy, Fast, Robust

23. few good reasons
Easy, Fast, Robust
Warning: an attacker can easier get your instances IPs
(use an unguessable DNS zone name)

24. Thank you
www.spreaker.com/marco
@pracucci