OSB-45: wrong variable usage

LCU/Maintenance/Docker/Jenkinsfile

@@ -11,27 +11,12 @@ pipeline {
                 label 'bob'
             }
             steps {
-            
                 echo 'building tag ${env.DOCKER_TAG}'
-                
-                script {
-                    dir ('LCU/Maintenance/Docker/BaseMaintenance/'){
-                        docker.build "lofar-maintenance-base:${env.DOCKER_TAG}"
-                    }
-                
-                    docker.build("lofar-maintenance-dbinterface:${env.DOCKER_TAG}",  "--build-arg TAG=${DOCKER_TAG}")
-
-                    dir ('LCU/Maintenance/Docker/RESTService/'){
-                        docker.build("lofar-maintenance-restservice:${env.DOCKER_TAG}", "--build-arg TAG=${DOCKER_TAG}")
-                    }
-                    
-                    dir ('LCU/Maintenance/Docker/RESTService/'){
-                        docker.build("lofar-maintenance-nginxproxy:${env.DOCKER_TAG}", "--build-arg TAG=${DOCKER_TAG}")
-                    }
-                    dir ('LCU/Maintenance/Docker/BackgroundWorkers'){
-                        docker.build("lofar-maintenance-backgroundworkers:${env.DOCKER_TAG}", "--build-arg TAG=${DOCKER_TAG}")
-                    }
-                }
+                docker.build "lofar-maintenance-base:${env.DOCKER_TAG} LCU/Maintenance/Docker/BaseMaintenance/"
+                docker.build "lofar-maintenance-dbinterface:${env.DOCKER_TAG} --build-arg TAG=${DOCKER_TAG} -f LCU/Maintenance/Docker/DBInterface/Dockerfile"
+                docker.build "lofar-maintenance-restservice:${env.DOCKER_TAG} --build-arg TAG=${DOCKER_TAG}"
+                docker.build "lofar-maintenance-nginxproxy:${env.DOCKER_TAG} --build-arg TAG=${DOCKER_TAG} LCU/Maintenance/Docker/RESTService/"
+                docker.build "lofar-maintenance-backgroundworkers:${env.DOCKER_TAG} --build-arg TAG=${DOCKER_TAG} LCU/Maintenance/Docker/BackgroundWorkers"
             }
         }
         stage('Test') {