Automating Jenkins Job Creation with Job DSL, XML Conversion, and API

Creating projects at scale in Jenkins is a challenge; this article shows how to automate Jenkins project creation using templates.

After installing the Job DSL plugin, you can either create projects directly with DSL or convert DSL to XML and create projects via the Jenkins API. The first method is more straightforward, but this guide focuses on the second method.

1. Generate template using Job DSL API

We need to install the Job DSL plugin first, then create the project using DSL.

URL: https://jenkinsci.github.io/job-dsl-plugin/

For example, using the official example, this defines a pipeline job with description, parameters, and Jenkinsfile location.

pipelineJob("test-schdule-service") {</code><code>  description("this is my first job")</code><code>  keepDependencies(false)</code><code>  parameters {</code><code>    choiceParam("test", [1, 2, 3], "")</code><code>  }</code><code>  definition {</code><code>    cpsScm {</code><code>      scm {</code><code>        git {</code><code>          remote {</code><code>            github("https://gitlab.com/xxx/xxx.git", "https")</code><code>            credentials("24982560-17fc-4589-819b-bc5bea89da77")</code><code>          }</code><code>          branch("*/master")</code><code>        }</code><code>      }</code><code>      scriptPath("Jenkinsfile")</code><code>    }</code><code>  }</code><code>  disabled(false)</code><code>}

2. Convert DSL → XML via Playground

URL: http://job-dsl.herokuapp.com/

3. Create project via Jenkins Core API

import javax.xml.transform.stream.StreamSource</code><code>import jenkins.model.Jenkins</code><code></code><code>//创建项目</code><code>void createOrUpdateJob(String name, String xml) {</code><code>    def j = Jenkins.instance</code><code>    String fullName = name</code><code>    if(name.contains('/')) {</code><code>        j = j.getItemByFullName(name.tokenize('/')[0..-2])</code><code>        name = name.tokenize('/')[ -1]</code><code>    }</code><code>    Jenkins.checkGoodName(name)</code><code>    if(j.getItem(name) == null) {</code><code>        println "Created job \"${fullName}\"."</code><code>        j.createProjectFromXML(name, new ByteArrayInputStream(xml.getBytes()))</code><code>        j.save()</code><code>    } else if(j.getItem(name).configFile.asString().trim() != xml.trim()) {</code><code>        j.getItem(name).updateByXml(new StreamSource(new ByteArrayInputStream(xml.getBytes())))</code><code>        j.getItem(name).save()</code><code>        println "Job \"${fullName}\" already exists.  Updated using XML."</code><code>    } else {</code><code>        println "Nothing changed.  Job \"${fullName}\" already exists."</code><code>    }</code><code>}</code><code></code><code>try {</code><code>    //just by trying to access properties should throw an exception</code><code>    itemName == null</code><code>    xmlData == null</code><code>    isPropertiesSet = true</code><code>} catch(MissingPropertyException e) {</code><code>    println 'ERROR Can\'t create job.'</code><code>    println 'ERROR Missing properties: itemName, xmlData'</code><code>    return</code><code>}</code><code></code><code>String xmlData = """<!-- 1. test-schdule-service -->
<flow-definition>
    <actions></actions>
    <description>this is my first job</description>
    <keepDependencies>false</keepDependencies>
    <properties>
        <hudson.model.ParametersDefinitionProperty>
            <parameterDefinitions>
                <hudson.model.ChoiceParameterDefinition>
                    <choices class='java.util.Arrays$ArrayList'>
                        <a class='string-array'>
                            <string>1</string>
                            <string>2</string>
                            <string>3</string>
                        </a>
                    </choices>
                    <name>test</name>
                    <description></description>
                </hudson.model.ChoiceParameterDefinition>
            </parameterDefinitions>
        </hudson.model.ParametersDefinitionProperty>
        <com.coravy.hudson.plugins.github.GithubProjectProperty>
            <projectUrl>https://github.com/https://gitlab.com/xxx/xxx.git/</projectUrl>
        </com.coravy.hudson.plugins.github.GithubProjectProperty>
    </properties>
    <triggers></triggers>
    <definition class='org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition'>
        <scriptPath>Jenkinsfile</scriptPath>
        <lightweight>false</lightweight>
        <scm class='hudson.plugins.git.GitSCM'>
            <userRemoteConfigs>
                <hudson.plugins.git.UserRemoteConfig>
                    <url>https://github.com/https://gitlab.com/xxx/xxx.git.git</url>
                    <credentialsId>24982560-17fc-4589-819b-bc5bea89da77</credentialsId>
                </hudson.plugins.git.UserRemoteConfig>
            </userRemoteConfigs>
            <branches>
                <hudson.plugins.git.BranchSpec>
                    <name>*/master</name>
                </hudson.plugins.git.BranchSpec>
            </branches>
            <configVersion>2</configVersion>
            <doGenerateSubmoduleConfigurations>false</doGenerateSubmoduleConfigurations>
            <gitTool>Default</gitTool>
            <browser class='hudson.plugins.git.browser.GithubWeb'>
                <url>https://github.com/https://gitlab.com/xxx/xxx.git/</url>
            </browser>
        </scm>
    </definition>
    <disabled>false</disabled>
</flow-definition>
"""</code><code>String itemName = "my-first-pipeline"</code><code></code><code>createOrUpdateJob(itemName, xmlData)

4. Run via Jenkins Script Console

Creation completed.

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Follow the link to the latest tutorial for more details.