Can I check if Environment variable exist or not in Jenkinsfile

Question

I am running Multibranch pipeline for my project.

The behaviour of Jenkinsfile should change according to the trigger. There are two events that triggeres the pipeline 1. Push event 2. Pull Request.

I am trying to check Environment variable 'CHANGE_ID' ('CHANGE_ID' will be available for Pull Request only).Reference .

So if pipeline is triggred by Push event and If check the 'CHANGE_ID' variable it throws exception (code works fine if pipeline gets triggered by Pull Request).

Code:

stage('groovyTest'){     node('mynode1') {         if (CHANGE_ID!=NULL){             echo "This is Pull request"         }else{             echo "This is Push request"         }     } } 

Error:

groovy.lang.MissingPropertyException: No such property: CHANGE_ID for class: groovy.lang.Binding     at groovy.lang.Binding.getVariable(Binding.java:63)     at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onGetProperty(SandboxInterceptor.java:224)     at org.kohsuke.groovy.sandbox.impl.Checker$4.call(Checker.java:241)     at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:238)     at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:221)     at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:221)     at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.getProperty(SandboxInvoker.java:28)     at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:20)     at WorkflowScript.run(WorkflowScript:5)     at ___cps.transform___(Native Method) 

How can I check the 'CHANGE_ID' variable exist or not in Jenkinsfile?

Answer 1

You may check it before use it:

 if (env.CHANGE_ID) {  ... 

From the doc

Environment variables accessible from Scripted Pipeline, for example: env.PATH or env.BUILD_ID. Consult the built-in Global Variable Reference for a complete, and up to date, list of environment variables available in Pipeline.

Answer 2

This is how it would look like for a declarative pipeline:

pipeline {     // ...     stages {         // ...         stage('Build') {             when {                 allOf {                     expression { env.CHANGE_ID != null }                     expression { env.CHANGE_TARGET != null }                 }             }             steps {                 echo "Building PR #${env.CHANGE_ID}"             }         }     } } 

To run a stage only when not building a PR:

when { expression { env.CHANGE_ID == null } }