如何将文件从 docker 虚拟机复制到 OS X 上的主机？

Question

I use OS X 10.13.3 , and my docker version as follow:

Client:
 Version:   17.12.0-ce
 API version:   1.35
 Go version:    go1.9.2
 Git commit:    c97c6d6
 Built: Wed Dec 27 20:03:51 2017
 OS/Arch:   darwin/amd64

Server:
 Engine:
  Version:  17.12.0-ce
  API version:  1.35 (minimum version 1.12)
  Go version:   go1.9.2
  Git commit:   c97c6d6
  Built:    Wed Dec 27 20:12:29 2017
  OS/Arch:  linux/amd64
  Experimental: true

I know docker is running in a vm on OS X, and I can get in by following command:

screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty

In docker's history version, docker use Docker.qcow2 as the image of vm. Local /Users direcotry is mounted into the docker vm, so I can copy a file to my home directory, such as /Users/username/Downloads :

cp /var/lib/docker/image/overlay2/repositories.json /Users/username/Downloads

In latest version, Docker use Docker.raw as the image of vm, and I can't copy file in that way.

How can I copy file from the vm to my OS X?

Answer 1

A possible workaround:

Add a local directory as a volume(bind-mount) for a container. In docker-compose.yml this would be like:

volumes:
       - wpdb:/var/lib/mysql 
       - ./db:/root 

wpdb is a docker volume would be inside the linux vm and inaccessible from the local mac directory

./db would be a bind-mount and accessible in the same directory as your docker-compose.yml file

Any file you copy into the /root directory would be available in your local mac directory ./db .

In the example above:

- ./db:/root 

would be a bind-mount.

This article may explain it more clearly:

Choosing Between Volume & Bind Mount

docker run -v $PWD:/home containername

Answer 2

It can be done by using docker cp

docker cp <CONTAINER_ID>:<SRC_PATH_ON_CONTAINER> <DEST_PATH_ON_LOCAL_MACHINE>

More details: Docker docs