Talk about Orc, our continuous deployment framework

1. Orc
Zero downtime deployments made easy
Tomas Doran (t0m)
@bobtfish
<bobtfish@bobtfish.net>
https://github.com/bobtfish/

2. Problem space:
• Multiple heterogeneous applications
• Multiple servers per app
• Multiple environments
• Custom deployment solutions / semi-
manual deployment

3. Observed problems:
• Support nightmare
• Failed / inconsistent deployments
• New applications extremely costly to
deploy

4. Solution:
• Application infrastructure contract
• Defined interface for infrastructure to
interact with your application:
• How to launch
• How to query health
• Any application which complies gets
continuous deployment - free

5. Reliable
• Contract conformity checked by a common
test suite
• CI builds to check deployability

6. Predictable
• Deployment is model driven
• Store desired state in ‘cmdb’
• Audit live servers, adjust reality to conform
to desired state
• State machine - easy to test!

7. Safe
• Each possible step in a deployment is a
state transition
• Sample live state after each transition - if
model doesn’t match reality, stop!
• Mcollective agent - flexible per-user + fact
based permissions for free

8. Architecture

9. Participation?
• Need to be able to cleanly remove
instances from load balancer
• Make load balancer health check do 2
things:
• Check app = healthy
• Check participation = true
• Tatin - tiny REST service to drop state into

10. Contract URIs
• App:
• http://localhost:xxxx/info/health
• http://localhost:xxxx/info/version
• Participation:
• http://localhost
:yyyy/app_name/environment_name/insta
nce_name

11. deployapp methods
• get status (health + version)
• enable participation
• disable participation
• upgrade version

12. State machine

13. Multiple instances
• Discover all instances
• Work out next transition for each instance
• Each transition has a weight
• Sort by weight - take highest weighted
• Repeat until no transitions left

14. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
Disable
host1 5 4 Y Y 1
part
Disable
host2 5 4 Y Y 1
part

15. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
host1 5 4 Y N Upgrade 2
Disable
host2 5 4 Y Y 1
part

16. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
Enable
host1 5 5 Y N 3
part
Disable
host2 5 4 Y Y 1
part

17. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
host1 5 5 Y Y None 0
Disable
host2 5 4 Y Y 1
part

18. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
host1 5 5 Y Y None 0
Disable
host2 5 4 Y N 1
part

19. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
host1 5 5 Y Y None 0
host2 5 4 Y N Upgrade 2

20. Simple example
Desired Actual Desired Actual
App Action Weight
version version part part
host1 5 5 Y Y None 0
host2 5 5 Y Y None 0

21. A/B groups
• Can run A/B groups of the same app with
different versions
• Can upgrade non-participating group, test,
then swap participation.
• Same model just works

22. Status
• Orc, deployapp + contract test harness
open source
• Docs still very lacking.
• You need to plug in your own repository
module (and your own launcher for non jar
apps)

23. Todo
• Better deployment (public gem+debs)
• Deployapp configuration rewrite
• http artifact fetcher
• More app launchers - rack/wsgi/psgi apps!
• Docs - specifically load balancer configs +
installation.

24. Code
• The ideas here are way more important
than the code
• Development sponsored by TIM Group
• Yes, of course we are hiring :)
• https://github.com/youdevise/orc

25. Thanks!
https://github.com/youdevise/orc
Questions?