This document discusses the evolution of Jenkins pipelines and whether freestyle jobs are still needed. It provides a brief history of Jenkins and key plugins from 2005 to 2018. Pipelines now support features like YAML, declarative syntax stored with code, and being triggered by SCM events. However, freestyle jobs may still be needed for simple utility jobs, conditional stages with restartability, and complex workflows. The talk demonstrates a shared library for conditionally running stages and restarting pipelines from checkpoints.

1. The state of Jenkins pipelines
or
do I still need freestyle jobs?
Day of Jenkins 2018
Andrey Devyatkin

2. Andrey Devyatkin
● Enjoying life
● Long time Jenkins hacker
● CI/CD enthusiast
● Writer of tools
● Fixer of things and projects
● Independent consultant

3. This talk is not… or at least trying not to be

4. Back in the days (2005) ...

5. As alternative to...

6. But first some scenarios...

7. Cron job

8. Daily build

9. Downstream
….

10. Event driven
Commit ….

11. Fan-out, fan-in
Commit ….

12. Fan-out, fan-in
Commit ….

13. Conditional builds/Build avoidance
Commit ….
?

14. So how do we implement all of that in
Jenkins...

15. Parameterized Trigger plugin, Join plugin (2009)

16. eXtreme Feedback Panel Plugin (2009)

17. Hudson -> Jenkins (2011)

18. Wall display plugin (2011)

19. Build Pipeline (2011)

20. Chuck Norris plugin (2011)

21. JobDSL (2012)

22. Build flow plugin (2012)

23. Meanwhile… (2011-2012)

24. Difference
● SaaS
● Almost no server configuration (web hooks mess, workers etc)
● YAML/Declarative pipelines
● Stored together with code
● By default do not have SCM block
● Always triggered by SCM (or SCM related - like PR) event

25. Delivery pipeline plugin (2013)

26. Workflow -> Pipelines -> Jenkinsfile (2014)

27. What was different - Hacker way
● Imperative
● Groovy and DSL
● Eventually declarative pipelines. Kind of

28. What was different - Pain
● Burden of legacy
● Plugins support
● Visualization mess
● Security
● nonCPS
● Confusion - declarative vs scripted

29. What was different
● Shared libraries
● Multibranch
● Resumable pipelines

30. Fast forward to 2018...

31. Where are we today?
● GitHub/BitBucket support
● But try doing Gerrit...
● Most of the plugins supported
● Good documentation
● Declarative pipeline… if you don’t go scripted
● Visualisation kind of works… if you don’t go scripted
● Possibly YAML-based pipelines
https://jenkins.io/blog/2018/06/15/simple-pull-request-plugin/
● Still no possibility to restart pipeline from certain point
https://issues.jenkins-ci.org/browse/JENKINS-33846

32. Where would I still go freestyle or scripted?
● Simple utility jobs unrelated to CI/CD of the target - stuff that you don’t put to
the Jenkinsfile
● Conditional stages (think test/build avoidance)
● Want to avoid to resuming of the pipeline after restart and do not want to set
org.jenkinsci.plugins.workflow.job.properties.DisableResumeJobProperty
● Complex workflow with the need to restart the flow from the certain point

33. About those conditional stages and restart from
checkpoint...

34. https://issues.jenkins-ci.org/browse/JENKINS-33846

35. A hacker way in action...

36. library identifier: 'praqma-shared@master', retriever: modernSCM(
[$class: 'GitSCMSource',
remote: 'https://github.com/Praqma/shared-pipeline.git',
credentialsId: ''])
stageWithCheckPoint("ConditionalEcho") {
echo "User decided to run me"
}

37. Source
https://github.com/Praqma/shared-pipeline/blo
b/master/vars/stageWithCheckPoint.groovy

38. What you see today is only a short moment of the flow

41. Thanks!
andrey9kin@a59.company
@andrey9kin