Jenkinsfile to run a command on each node

runon-each-node.groovy

/*
Created by: Marcos Cano
Team: DevOps
Date: 7/7/17
*/ 
stage("Run cmd on each node") {

	def node_names=nodeNames()

	for (String item:node_names) {
	  	println "************* RUNNING IN: ${item} *************"
	  	try{
		  	timeout(time: 100, unit: 'SECONDS'){
			    node(item) {	    
			      stdout = sh (
			      	script: "uname -a",
			      	returnStdout: true,
			      	returnStderr: true
			      	).trim()
			      println stdout
			      writeFile file: "${item}.txt", text: stdout
			      
			      archiveArtifacts '*.txt'
			    }

			}
		}catch(e){
			println "ERROR " +item " Timed Out"  
			println e
		}
	}



}

@NonCPS
def nodeNames() {
   return jenkins.model.Jenkins.instance.nodes.collect { node -> 
   	  node.name
  }
}

Thank you!
Unfortunately I did not have enough access rights for Jenkins.instance.nodes, so I just created a static list of nodes.