Jenkins CI in Action discusses Continuous Integration (CI) and the Jenkins platform. It provides an overview of what CI is, who Jenkins is as a platform for CI, and why you might want to use Jenkins. It also briefly discusses the Gerrit alternative and common Jenkins workflows like using Gerrit as a trigger or running builds on a schedule. Tips are provided for optimizing Jenkins performance.

1. Jenkins CI in Action
by Mikhail Pobolovets

2. Foreword
● Senior Ruby developer/Team lead
at Altoros Systems
● Ruby developer since 2007
● Haskell and Erlang enthusiast
● https://github.com/styx

3. What is CI?
Continuous Integration is a software
development practice where members of a team
integrate their work frequently, usually each
person integrates at least daily - leading to
multiple integrations per day. Each integration is
verified by an automated build (including test) to
detect integration errors as quickly as possible.
– Martin Fowler

4. Who is Jenkins?
● Written in Java, but thats not a problem
● Platform with minimum functionality
● Plugins support
– Gerrit, Github, IRC, Jabber, Skype, Vagrant, Rake,
LDAP
– About 780 plugins
● Distributed builds (Master – Slave)

5. I want one!

6. So why you might want Jenkins?
● Bad commit? You will know about in 5 minutes
● Code delivery is easier and faster
● Automation of annoying tasks
● No need to invent a wheel, you already have a
platform
● The biggest community among other CI
products

7. Alternatives

8. Gerrit
Gerrit is a web-based team software code
review tool.

10. Workflows
● With Gerrit trigger – Main workflow for Devs
– New patch set / Draft published
– Special comment posted
– Special phrase in commit message to skip build
● By schedule
– Integration testing (nightly)
● By dependency build
– Special case if you have projects with shared code
base

11. Gerrit workflow
Verified
Pull
R
eview
ed
Push
Pull
Subm
it

12. Tweaks
● GC tweaks
● Parallel Tests
https://github.com/grosser/parallel_tests
● Pspec
https://github.com/FUT/pspec
● Skip part of the test suite if possible
● Rubocop
● Simple script to find out basic errors (debugger)
● Brakeman