docker container cp

docker container cp

Description

Copy files/folders between a container and the local filesystem

Usage

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

Options

Parent command

Extended description

Copy files/folders between a container and the local filesystem

Use ‘-‘ as the source to read a tar archive from stdin and extract it to a directory destination in a container. Use ‘-‘ as the destination to stream a tar archive of a container source to stdout.

Examples

Suppose a container has finished producing some output as a file it saves to somewhere in its filesystem. This could be the output of a build job or some other computation. You can copy these outputs from the container to a location on your local host.

If you want to copy the /tmp/foo directory from a container to the existing /tmp directory on your host. If you run docker container cp in your ~ (home) directory on the local host:

$ docker container cp compassionate_darwin:tmp/foo /tmp

Docker creates a /tmp/foo directory on your host. Alternatively, you can omit the leading slash in the command. If you execute this command from your home directory:

$ docker container cp compassionate_darwin:tmp/foo tmp

If ~/tmp does not exist, Docker will create it and copy the contents of /tmp/foo from the container into this new directory. If ~/tmp already exists as a directory, then Docker will copy the contents of /tmp/foo from the container into a directory at ~/tmp/foo.

When copying a single file to an existing LOCALPATH, the docker container cp command will either overwrite the contents of LOCALPATH if it is a file or place it into LOCALPATH if it is a directory, overwriting an existing file of the same name if one exists. For example, this command:

$ docker container cp sharp_ptolemy:/tmp/foo/myfile.txt /test

If /test does not exist on the local machine, it will be created as a file with the contents of /tmp/foo/myfile.txt from the container. If /test exists as a file, it will be overwritten. Lastly, if /test exists as a directory, the file will be copied to /test/myfile.txt.

Next, suppose you want to copy a file or folder into a container. For example, this could be a configuration file or some other input to a long running computation that you would like to place into a created container before it starts. This is useful because it does not require the configuration file or other input to exist in the container image.

If you have a file, config.yml, in the current directory on your local host and wish to copy it to an existing directory at /etc/my-app.d in a container, this command can be used:

$ docker container cp config.yml myappcontainer:/etc/my-app.d

If you have several files in a local directory /config which you need to copy to a directory /etc/my-app.d in a container:

$ docker container cp /config/. myappcontainer:/etc/my-app.d

The above command will copy the contents of the local /config directory into the directory /etc/my-app.d in the container.

Finally, if you want to copy a symbolic link into a container, you typically want to copy the linked target and not the link itself. To copy the target, use the -L option, for example:

$ ln -s /tmp/somefile /tmp/somefile.ln
$ docker container cp -L /tmp/somefile.ln myappcontainer:/tmp/

This command copies content of the local /tmp/somefile into the file /tmp/somefile.ln in the container. Without -L option, the /tmp/somefile.ln preserves its symbolic link but not its content.