title: How can I copy a directory or file to a docker image from localhost on ubuntu14.04?
body: <p>when i add a file or directory to docker image by a Dockerfile, I use ADD or COPY , but the file  path i want to add or copy must a relative path to the Dockerfile's directory. Is there a method for adding a file or directory from localhost to docker image by using absolute path? by the way, why the "docker cp" can only support copying file from docker image to localhost? on the contrary , it doesn't work ?</p>