Code enhancements

Jenkinsfile

@@ -83,7 +83,7 @@ pipeline {
           for (String item : service_update.split()) {
             echo "Updating ${item}"
             sh "set"
-            sh "docker node ls"
+            sh "DOCKER_HOST=${DHOST} docker node ls"
             try{
                sh "docker service update ${item} --image ${DOCKER_REGISTRY}/iru/${DOCKER_IMAGE}:${NEWTAG}"
             }