Maven tool is not set in Jenkins pipeline

Question

I have this stage in my Jenkins pipeline:

   stage('Build') {
       def mvnHome = tool 'M3'
       sh '''for f in i7j-*; do
                 (cd $f && ${mvnHome}/bin/mvn clean package)
             done
             wait'''
   }

In Jenkins » Manage Jenkins » Global Tool Configuration I have a Maven installation called M3, version 3.3.9.

When running this pipeline, mvnHome is empty because I get this in the log:

+ /bin/mvn clean install -Dmaven.test.skip=true
/var/lib/jenkins/jobs/***SNIP***/script.sh: 3: /var/lib/jenkins/jobs/***SNIP***/script.sh: /bin/mvn: not found

I did find a path /var/lib/jenkins/tools/hudson.tasks.Maven_MavenInstallation/M3 on the Jenkins server, which works, but I would prefer not to use a hard coded path to mvn in this script.

How do I fix this?

---

EDIT: Summary of the answer, using tool and withEnv.

My working code is now:

   stage('Build') {
        def mvn_version = 'M3'
        withEnv( ["PATH+MAVEN=${tool mvn_version}/bin"] ) {
        sh '''for f in i7j-*; do
                (cd $f && mvn clean package -Dmaven.test.skip=true -Dadditionalparam=-Xdoclint:none  | tee ../jel-mvn-$f.log) &
              done
              wait'''
        }
   }

Answer 1

You can use your Tools in Jenkinsfile with the tool and withEnv snippets.

Should looks like this:

def mvn_version = 'M3'
withEnv( ["PATH+MAVEN=${tool mvn_version}/bin"] ) {
  //sh "mvn clean package"
}

Answer 2

The easiest way should be to use is tools directives:

pipeline {
  agent any
  tools {
    maven 'M3'
  }
  stages {
    stage('Build') {
      steps {
        sh 'mvn -B -DskipTests clean package'
      }
    }
  }
}

M3 is the name pre-configured in Global Tool Configuration, see the docs: https://jenkins.io/doc/book/pipeline/syntax/#tools