node('docker') {
    stage('Build within docker') {
        // path to the workspace on the local machine and wthin the docker image
        workspace = env.WORKSPACE
        workspaceDocker = '/workspace'

        image = docker.image("ubuntu:18.04")
        image.pull()

        image.inside("-v ${workspace}:${workspaceDocker}") {
            sh 'pwd'

            sh """#!/bin/sh
            cd ${workspaceDocker}
            pwd
            """

            // this fails with the following error:
            // java.nio.file.AccessDeniedException: /workspace
            dir(workspaceDocker) {
                sh 'pwd'
            }
        }
    }
}