docker cp <containerId>:/file/path/within/container /host/path/target
参考自:
http://stackoverflow.com/questions/22907231/copying-files-from-host-to-docker-container
 
docker run -v /path/to/hostdir:/mnt $container 在容器内拷贝 cp /mnt/sourcefile /path/to/destfile
 
A. 获取容器名称或者id :
$ docker ps
 
B. 获取整个容器的id
$ docker inspect -f   ‘{{.Id}}‘  步骤A获取的名称或者id
 
C. 在主机上拷贝文件:
$ sudo cp path-file-host /var/lib/docker/aufs/mnt/FULL_CONTAINER_ID/PATH-NEW-FILE 或者 $ sudo cp path-file-host /var/lib/docker/devicemapper/mnt/123abc<<id>>/rootfs/root
 
例子:
$ docker ps
CONTAINER ID      IMAGE    COMMAND       CREATED      STATUS       PORTS        NAMES
d8e703d7e303   solidleon/ssh:latest      /usr/sbin/sshd -D                      cranky_pare
$ docker inspect -f   ‘{{.Id}}‘ cranky_pare
or 
$ docker inspect -f   ‘{{.Id}}‘ d8e703d7e303
d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5
$ sudo cp file.txt /var/lib/docker/aufs/mnt/**d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5
 
docker run -i ubuntu /bin/bash -c ‘cat > /path/to/container/file‘ < /path/to/host/file/
或者
docker exec -it <container_id> bash -c ‘cat > /path/to/container/file‘ < /path/to/host/file/
 
原文:http://blog.csdn.net/yangzhenping/article/details/43667785