Load podTemplate from K8s ConfigMap

Jenkinsfile.groovy

// Pull the configmap from the K8 API using the Jenkins service account and store it in the podTemplateYaml variable
def podTemplateYaml = ''
openshift.withCluster() {
    openshift.withProject() {
        cmsel = opeshift.selector("configmap", [role: 'jenkins-slave' ])
        cmsel.watch {
            podTemplateYaml = it.object().data[bw-maven]
        }
    }
}

pipeline {
    agent {
        kubernetes {
          label "zaproxy-maven-sidecars-${env.BUILD_ID}"
          defaultContainer 'jenkins-slave-mvn'
          yaml podTemplateYaml                              // Use the podTemplateYaml variable HERE to define the agent in Jenkins
        }
    }
    options {
        timeout(time: 15, unit: 'MINUTES')
    }
    environment {
        PROJECT_NAME = 'adjective-service'
    }
    triggers {
        gitlab(
            triggerOnPush: true, 
            triggerOnMergeRequest: true, 
            branchFilterType: 'NameBasedFilter', 
            includeBranchesSpec: 'master',
            addVoteOnMergeRequest: true,
            triggerOnNoteRequest: false,
            addNoteOnMergeRequest: true,
            acceptMergeRequestOnSuccess: false
        )
    }
  
  // Stages and steps here.
}