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% podman-cp(1)

NAME

podman-cp - Copy files/folders between a container and the local filesystem

SYNOPSIS

podman cp [container:]src_path [container:]dest_path

podman container cp [container:]src_path [container:]dest_path

DESCRIPTION

Copy the contents of src_path to the dest_path. You can copy from the container's filesystem to the local machine or the reverse, from the local filesystem to the container. If - is specified for either the SRC_PATH or DEST_PATH, you can also stream a tar archive from STDIN or to STDOUT.

The CONTAINER can be a running or stopped container. The src_path or dest_path can be a file or directory.

The podman cp command assumes container paths are relative to the container's root directory (i.e., /).

This means supplying the initial forward slash is optional;

The command sees compassionate_darwin:/tmp/foo/myfile.txt and compassionate_darwin:tmp/foo/myfile.txt as identical.

Local machine paths can be an absolute or relative value. The command interprets a local machine's relative paths as relative to the current working directory where podman cp is run.

Assuming a path separator of /, a first argument of src_path and second argument of dest_path, the behavior is as follows:

src_path specifies a file

  • dest_path does not exist
    • the file is saved to a file created at dest_path (note that parent directory must exist)
  • dest_path exists and is a file
    • the destination is overwritten with the source file's contents
  • dest_path exists and is a directory
    • the file is copied into this directory using the basename from src_path

src_path specifies a directory

  • dest_path does not exist
    • dest_path is created as a directory and the contents of the source directory are copied into this directory
  • dest_path exists and is a file
    • Error condition: cannot copy a directory to a file
  • dest_path exists and is a directory
    • src_path ends with /
      • the source directory is copied into this directory
    • src_path ends with /. (i.e., slash followed by dot)
      • the content of the source directory is copied into this directory

The command requires src_path and dest_path to exist according to the above rules.

If src_path is local and is a symbolic link, the symbolic target, is copied by default.

A colon (:) is used as a delimiter between CONTAINER and its path.

You can also use : when specifying paths to a src_path or dest_path on a local machine, for example, file:name.txt.

If you use a : in a local machine path, you must be explicit with a relative or absolute path, for example: /path/to/file:name.txt or ./file:name.txt

Using - as the src_path streams the contents of STDIN as a tar archive. The command extracts the content of the tar to the DEST_PATH in the container. In this case, dest_path must specify a directory. Using - as the dest_path streams the contents of the resource (can be a directory) as a tar archive to STDOUT.

Note that podman cp ignores permission errors when copying from a running rootless container. The TTY devices inside a rootless container are owned by the host's root user and hence cannot be read inside the container's user namespace.

OPTIONS

ALTERNATIVES

Podman has much stronger capabilities than just podman cp to achieve copy files between host and container.

Using standard podman-mount and podman-umount takes advantage of the entire linux tool chain, rather then just cp.

If a user wants to copy contents out of a container or into a container, they can execute a few simple commands.

You can copy from the container's file system to the local machine or the reverse, from the local filesystem to the container.

If you want to copy the /etc/foobar directory out of a container and onto /tmp on the host, you could execute the following commands:

mnt=$(podman mount CONTAINERID)
cp -R ${mnt}/etc/foobar /tmp
podman umount CONTAINERID

If you want to untar a tar ball into a container, you can execute these commands:

mnt=$(podman mount CONTAINERID)
tar xf content.tgz -C ${mnt}
podman umount CONTAINERID

One last example, if you want to install a package into a container that does not have dnf installed, you could execute something like:

mnt=$(podman mount CONTAINERID)
dnf install --installroot=${mnt} httpd
chroot ${mnt} rm -rf /var/log/dnf /var/cache/dnf
podman umount CONTAINERID

This shows that using podman mount and podman umount you can use all of the standard linux tools for moving files into and out of containers, not just the cp command.

EXAMPLE

podman cp /myapp/app.conf containerID:/myapp/app.conf

podman cp /home/myuser/myfiles.tar containerID:/tmp

podman cp containerID:/myapp/ /myapp/

podman cp containerID:/home/myuser/. /home/myuser/

podman cp - containerID:/myfiles.tar.gz < myfiles.tar.gz

SEE ALSO

podman(1), podman-mount(1), podman-umount(1)