Hi. if I understood well, You need to write files out of container, in your local filesystem and use them inside the container, right?....Well, you can use docker volumns (-v option):

$ docker run -it --name test-hadoop -p 9864:9864 -p 9870:9870 -p 8088:8088 -v <local_filesystem_path>:/home/hduser/ --hostname <myhost> hadoop

When you write files into <local_filesystem_path> these will write into the container as well.

Let me know if this help you.

Cheers.