Swap Libraries
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The purpose of the Jenkins Templating Engine is three fold:
Now organizations can coalesce around a portfolio of centralized, reusable pipeline libraries representing different tool integrations for their CI/CD pipelines.
Separating a pipeline into a templates, configuration file, and pipeline libraries can also be thought of as separating the business logic of your pipeline from the technical implementation. In our experience, it is significantly easier to manage a template backed by modularized pipeline libraries than it is to manage application-specific Jenkinsfiles.
With the traditional Jenkinsfile defined within, and duplicated across, source code repositories it can be very challenging to ensure the same process is being followed by disparate application development teams and confirm that organizational policies around code quality and security are being met. JTE brings a level of governance to your pipelines by centralizing the definition of the pipeline workflow to a common place. |
To demonstrate the reusability of pipeline templates, what would happen if the development team switched to using Gradle?
All we would have to do is create a gradle library that implements the build() step of the pipeline template.
Create the Gradle Library
Remember that a library is just a subdirectory within the Base Directory configured as part of the Library Source in Jenkins. So to create the gradle library we should create a gradle directory under the libraries directory.
Then, to implement the build() step for the pipeline, create a build.groovy file within the newly created gradle subdirectory.
When you have created the new gradle directory and build.groovy file, your repository file structure will now be:
.
└── libraries
├── gradle
│ └── steps
│ └── build.groovy
├── maven
│ └── steps
│ └── build.groovy
└── sonarqube
└── steps
└── static_code_analysis.groovyThe contents of the build.groovy should be:
void call(){
stage("Gradle: Build"){
println "build from the gradle library"
}
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If you added this library on your local computer instead of through the GitHub UI, then please make sure you’ve pushed this change to the master branch of the repository. |
Swap from Maven to Gradle
Now that we have a swappable implementation for the build() step of the pipeline template, switching from Maven to Gradle is as easy as changing the pipeline configuration.
Going back to the job configuration, in the Pipeline Configuration text box, swap the maven line to gradle and click Save.
The pipeline configuration should now be:
libraries{
gradle
sonarqube
}Run the Pipeline
Follow the same steps as before to run the job again and checkout the build logs:
Started by user admin
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[JTE] Pipeline Configuration Modifications (show)
[JTE] Loading Library gradle (show)
[JTE] Library gradle does not have a configuration file.
[JTE] Loading Library sonarqube (show)
[JTE] Library sonarqube does not have a configuration file.
[JTE] Obtained Pipeline Template from job configuration
[Pipeline] node
Running on Jenkins in /var/jenkins_home/workspace/single-job
[Pipeline] {
[Pipeline] writeFile
[Pipeline] archiveArtifacts
Archiving artifacts
[Pipeline] }
[Pipeline] // node
[JTE] [Step - gradle/build.call()]
[Pipeline] stage
[Pipeline] { (Gradle: Build)
[Pipeline] echo
build from the gradle library
[Pipeline] }
[Pipeline] // stage
[JTE] [Step - sonarqube/static_code_analysis.call()]
[Pipeline] stage
[Pipeline] { (SonarQube: Static Code Analysis)
[Pipeline] echo
static code analysis from the sonarqube library
[Pipeline] }
[Pipeline] // stage
[Pipeline] End of Pipeline
Finished: SUCCESS