Copy files or directories between host and container filesystems. More information: https://docs.docker.com/engine/reference/commandline/cp.
docker cp path/to/file_or_directory_on_host container_name:path/to/file_or_directory_in_container
docker cp container_name:path/to/file_or_directory_in_container path/to/file_or_directory_on_host
docker cp --follow-link path/to/symlink_on_host container_name:path/to/file_or_directory_in_container