如何在docker容器和主机之间共享数据？

Question

I tried to share data between the docker container and the host, for example by adding the parameter -v /Users/name/Desktop/Tutorials:/cntk/Tutorials to the docker run command, but I noticed that it also deletes all the files on the docker contained in /cntk/Tutorials.

My question is how to make the same link, but having instead all the files in /cntk/Tutorials copied to the host (at /Users/name/Desktop/Tutorials)

Thank you

Answer 1

Unfortunately that it is not possible, take a look here . That is because this is how mounting works in Linux.

Answer 2

It is not correct to say that the files were deleted. They are still present in the underlying image, but the act of mounting another directory at the same path has obscured them. They exist, but are not accessible in this condition.

One way you can accomplish this is by mounting a volume into your container at a different path , and then copying the container's files to that path. Something like this.

Mount a host volume using a different path than the one the container already has for the files you are interested in.

docker run -v /Users/name/Desktop/Tutorials:/cntk/Tutorials2 [...]

Now, execute a command that will copy the files already in the docker image, into the mounted volume from the outside host.

docker exec <container-id> cp -r /cntk/Tutorials /cntk/Tutorials2

Answer 3

The docker cp command allows you to copy files/folders on demand between host and the container:

docker cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH|-
docker cp [OPTIONS] SRC_PATH|- CONTAINER:DEST_PATH

docker cp ContainerName:/home/data.txt . <== copy from container to host

docker cp ./test.txt ContainerName:/test.txt <== copy from host to container
docker cp ContainerName:/test.txt ./test2.txt <== copy from container to host

For details run docker cp --help