A brief introduction to Jenkins Shared Libraries

1. Jenkins Shared Libraries
Paolo D'Incau
@pdincau

2. DevOps
Teams are cross-functional and have end-to-end
responsibility on their products.

3. Not only features!
Teams are also in charge to support production,
monitor applications and to create/maintain
pipelines that fit their needs best.

4. Jenkins pipelines
With Jenkins you can create pipelines using
groovy code.
Deployment becomes developer friendly!

5. Beware duplication
Some steps (e.g. deploy) are very similar across
teams: you don’t want each team to reinvent the
wheel.

6. Separate concerns
You may want to make some things “opaque” to the
teams (e.g. changes in orchestrator version, IP
address, …).

7. Shared libraries
You can harness Jenkins Shared Libraries and
create a set of functionalities that each team can
import and use in their pipelines.

8. Example
Let’s see how we can write a library that each team
will use to deploy a given containerised application
on a generic orchestrator.

9. Code organisation

10. src and vars
Directory ‘src’ has a standard Java source directory
structure. It is added to the classpath when
executing your pipelines.
Directory ‘vars’ contains scripts that define global
variables accessible from your pipelines.

11. Tips I

12. Serializable
Your classes should implement Serializable when
they have state, this is needed in order to allow
Jenkins to stop and resume your pipelines properly.

13. Tips II

14. Logging
You can’t log directory using ‘println’ or ‘echo’, you
have to pass through ‘steps#echo’ which is available
in the pipeline context.

15. Configuration

16. Use

17. Conclusions
Jenkins shared libraries are a wonderful tool if you
want to ‘DRY’ some common patterns that emerged
in your pipelines.
Remember that you are inside Jenkins, so things may
behave a little different from what you think.

18. www.xpeppers.com
/xpepperssrl@xpeppers