Jenkins pipeline template

Question

We have several Java projects. Each project has its own delivery pipeline.

All pipelines have the following steps in common (simplified):

• Build project
• Release project
• Deploy to test environment
• Deploy to production environment

The project pipelines only differ in project specific properties such as service names or the IP addresses of test and production environment.

The questions are: How could we avoid the boilerplate that all projects have in common? Does Jenkins "Pipeline as code" provide something like pipeline templates?

I could imagine that a template would save a lot of redundant code/steps in our project pipelines. Therefore it would be much easier to setup a new project, maintain the pipeline, keep the pipeline in sync...

Answer 1

An approach that works well for us is to put parts of the pipeline (those that all projects have in common) or even the whole pipeline into a Jenkins shared library.

Example

The following script (template.groovy) is defined as global variable in a Jenkins shared library. The method creates a new declarative pipeline (it also works for scripted pipeline syntax). All project specific properties are provided via the templateParams map.

/**
 * Defines a pipeline template (as a sample with one job parameter 
 * that should be common for all pipelines)
 */
def createMyStandardDeclarativePipeline(Map templateParams) {   

    pipeline {
        agent any
        parameters {
            string(name: 'myInput', description: 'Some pipeline parameters')
        }
        stages {
            stage('Stage one') {
                steps {
                    script {
                        echo "Parameter from template creation: " + templateParams.someParam
                    }
                }
            }
            stage('Stage two') {
                steps {
                    script {
                        echo "Job input parameter: " + params.myInput
                    }
                }
            }
        }
    }
}

Using this global variable, the following line creates a pipeline from our template:

template.createMyStandardDeclarativePipeline(someParam: 'myParam')

Conclusion

This concept makes it easy to define pipeline templates and reuse them in several projects.

Applied on the example given in the question, you can create a delivery pipeline for a project with a simple one-liner:

template.createStandardDeliveryPipeline(serviceName: 'myService', 
                                        testEnv: '192.168.99.104', 
                                        productionEnv: '192.168.99.105')

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Update (30-09-2017): Declaring a pipeline block in a shared library is now officially supported with Declarative Pipelines version 1.2 . See: https://jenkins.io/doc/book/pipeline/shared-libraries/#defining-declarative-pipelines

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Update (06-10-2017): An extended example can now be found here: https://jenkins.io/blog/2017/10/02/pipeline-templates-with-shared-libraries/