Java / Opening Open Source the Jenkins Way - Nicolas de Loof, CloudBees

Opening Opensource the Jenkins Way

BreizhCamp 17 juin 2011

©2011 Cloud Bees, Inc. All Rights Reserved

2 ©2011 CloudBees, Inc. All Rights Reserved

Nicolas De loof

•  Java-Boy •  DevOps at •  (ex-)Committer Maven

•  JUG-Leader

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•  de facto continuous integration Server in Java ecosystem (non exclusive)

•  Basis for Software Factory automation o Q&A Code inspection o Release management o Continuous deployment o Business Intelligence …


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Hudson / Jenkins : the fork


KK create Hudson as a Hobby

Hudson is adopted world wide

Oracle aquire SUN

Oracle register « Hudson » trademark

Issues with java.net infrastructure

Oracle uses trademark as a weapon

Vote to rename the project and move to GitHub

Jenkins defines it’s own process

Here we are

Sonatype join Oracle Hudson

Jenkins

moved to GitHub and proposed to Eclipse FoundaKon Hudson

6 ©2011 CloudBees, Inc. All Rights Reserved

•  13 000 downloads / week •  1 500 member on jenkins-users •  4 000 followers @jenkinsci

User choosed Jenkins

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•  900 members on jenkins-dev •  48 active contributors, 94 publicized •  170 Pull-requests from occasional

contributors •  11,3 changes per release

(6,7 before the fork)

… as Developers did


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•  Voice committer •  Committer •  Contributor •  Supporting User •  User

Standard OSS model « meritocratic »


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1.  Use the tool 2.  Contribute to user-forum 3.  Get familiar with the code 4.  Contribute to dev-forum 5.  Fix bugs and post patches 6.  Be nice with everybody 7.  Do some lobbying

How to become a Committer …


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•  Difficult to get into the code •  Difficult to get spare time •  Difficult to fix bug or add new features •  Laborious to create and maintain patches •  Frustrating to wait for approval

How many talentuous guys do we loose here ?

In practice…


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My personal experience


MoKvaKon (# of contribuKons)

(never occurred)

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•  Rule #1 : lower the contribution barrier

The Jenkins-way


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Want to contribute ?


Ask for commit

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« With great power, comes great responsibility »

Self-censored contributors


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•  Discover a regression : revert

•  Test harness to the rescue (still much to do there)

Possible if there is few changes between releases !

Hey, this is SCM role after all !


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•  Rule #2 : Release often (even more)

The Jenkins-way


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•  One release per week •  Few changes between releases •  Easy to rollback when something is

broken

•  + « stable but older » branch (3 month) with Critical bug fixes only

Jenkins releases


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•  Contributor may ask for code review •  Contribution may require few changes

before beeing applied •  We don’t want to discourage contributors

WTF ?


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•  Diff format is definitly not a sexy format for humans

> +@Deprecated > +public class Base64 > +{ > + public Base64() > + { > + super();

Does it really need to call Object.super(). Can we not leave it with the default constructor as Plexus' original has?

> + }

Diff format (SVN patch)


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GitHub pull request


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•  Rule #3 : Tools matter, use the right ones

The Jenkins-way


patch

Pull request + Commit paTern

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•  Origin of the Hudson/Jenkins fork (java.net outage)

•  200 forks on Jenkins GitHub repo ! •  170 pull requests

Jenkins at GitHub


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What about CLA ?


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•  Constrain contributors to transfer Intellectual Property

•  … but not to ensure they have •  License is not a guarantee of freedom

•  This is a lawyers artifact

What is a CLA for ?


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•  Rule #4 : We are developers, not lawyers

The Jenkins-way


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•  250 plugins ! (maven plugin is the only one in core)

•  Even growing ecosystem •  Contributor can focus on some plugin

that bring them value daily

Modular design


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•  Extension point with runtime discovery •  Need to plug somewhere in Jenkins ? add a new extension point

•  Some idea for a new plugin ? add for a repo on github/jenkins-ci

Extensibility


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•  Rule #5 : design for extensibility

Multiple technical solutions (incl. @Inject)

The Jenkins way


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•  User forum

•  Dev forum

•  Private forum

•  (+ lobbying)

Multiple discussion levels


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•  Need for private discussion when it could hurt someone

  invitation for new Committers

… but we don’t have to « filter » committers anymore

WTF ?


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•  All discussions are public – On jenkins-dev – On irc #jenkinsci

•  Meeting bi-weekly on irc – Logged by irc-bot for later availability

http://meetings.jenkins-ci.org/jenkins

transparency


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•  24/7 on #jenkins •  Active reader on mailing lists •  Join the bi-weekly #irc meeting •  Read the meeting minutes

Multiple level of participation


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Rule #6 : Make things transparent

The Jenkins way


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•  Multiple levels of commitment   24/7 eMail addict   filter mails by subject   discuss major themes on bi-weekly meeting   read meeting notes

e-Mail avalanche syndrom


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•  Many contributor involved •  Everyone can commit (with care) •  No need for long debates thanks to small

release cycles and transparency

•  But… project still needs some sort of lead

Lead


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•  … but not a despot !

« Benevolent Dictator For Life »-syndrom

A Lead


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•  Highly active contributor •  Good knowledge of project history •  Good technical skills •  Visionary •  Newbie-compliant •  Not egocentric

Lead must be …


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•  Kohsuke Kawaguchi •  Andrew Bayer •  Dean Yu

(all from distinct companies) And discuss in public !

Lead-commitee is safer


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•  Rule #7 : choose a good Lead model

focus first on building a community

The Jenkins way


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« all from distinct companies » ?

Opensource (x)or Business


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•  Nectar : enhanced & supported Jenkins •  DEV@Cloud : hosted software factory •  RUN@Cloud : Java PaaS

•  Public : hosted by Amazon •  Private : on your own virtualized infra

CloudBees in 5 words


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•  KK is a CloudBees employee

… but CloudBees engaged to never interfere with Jenkins Lead committee

•  DEV@Cloud is awesome thanks to active opensource ecosystem !

CloudBees vs OpenSource


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•  CloudBees contributes bugfixes to OSS

CloudBees vs OpenSource


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•  Q&A, stabilised + supported •  Some entreprise dedicated plugins

o Security (RBAC) o Virtualisation, auto-scaling,

hypervisor integration o Jobs classification (folders) o Advanced Backup o …

Nectar value for entreprises


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•  Jenkins cluster •  Multi-tenant masters •  Pool of slaves •  Automatic provisionning

– On phisical or virtual machines •  Centralised management

(plugins, upgrades, default config…)

DEV@Cloud Private Edition


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•  Thanks to flexible Jenkins model •  Easiest maintenance •  Easiest contributions to oss •  All Jenkins improvements are good for

CloudBees •  All time focused on Jenkins dev&support

is good for Jenkins

All thoses features are Plugins !


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•  I’m trying to for GWT-maven-plugin

Does Jenkins model apply elsewhere ?


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•  lower the contribution barrier just ask to join the team !

•  release often one release per month

•  tools matter moved from codehaus svn to GitHub

•  make it transparent everything happens on googlegroups

•  choose a good lead-model myself + Olivier Lamy, may change …

•  design for extensibility more investigation required here

Applying rules


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•  Future will say…

•  Allready some contributors to join : o  complaining about missing features, o  encouraged to contribute, o  added to team, o  they fixed issues by themself !

•  Salvador Diaz to analyse Pull Request •  Pierre-Yves Ricau committed 5 fixes •  .. an M2Eclipse configurator

Does it work ?


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Q&A

Thank you


Java / Opening Open Source the Jenkins Way - Nicolas de Loof, CloudBees

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