% DOCKER(1) Docker User Manuals % Docker Community % JUNE 2014
docker-cp - Copy files/folders between a container and the local filesystem.
docker cp [--help] CONTAINER:PATH LOCALPATH|- LOCALPATH|- CONTAINER:PATH
In the first synopsis form, the docker cp
utility copies the contents of PATH
from the filesystem of CONTAINER
to the LOCALPATH
(or stream as a tar archive to STDOUT
if -
is specified).
In the second synopsis form, the contents of LOCALPATH
(or a tar archive streamed from STDIN
if -
is specified) are copied from the local machine to PATH
in the filesystem of CONTAINER
.
You can copy to or from either a running or stopped container. The PATH
can be a file or directory. The docker cp
command assumes all CONTAINER:PATH
values are relative to the /
(root) directory of the container. 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. If a LOCALPATH
value is not absolute, is it considered relative to the current working directory.
Behavior is similar to the common Unix utility cp -a
in that directories are copied recursively with permissions preserved if possible. Ownership is set to the user and primary group on the receiving end of the transfer. For example, files copied to a container will be created with UID:GID
of the root user. Files copied to the local machine will be created with the UID:GID
of the user which invoked the docker cp
command.
Assuming a path separator of /
, a first argument of SRC_PATH
and second argument of DST_PATH
, the behavior is as follows:
SRC_PATH
specifies a fileDST_PATH
does not existDST_PATH
DST_PATH
does not exist and ends with /
DST_PATH
exists and is a fileDST_PATH
exists and is a directorySRC_PATH
SRC_PATH
specifies a directoryDST_PATH
does not existDST_PATH
is created as a directory and the contents of the source directory are copied into this directoryDST_PATH
exists and is a fileDST_PATH
exists and is a directorySRC_PATH
does not end with /.
SRC_PATH
does end with /.
The command requires SRC_PATH
and DST_PATH
to exist according to the above rules. If SRC_PATH
is local and is a symbolic link, the symbolic link, not the target, is copied.
A colon (:
) is used as a delimiter between CONTAINER
and PATH
, but :
could also be in a valid LOCALPATH
, like file:name.txt
. This ambiguity is resolved by requiring a LOCALPATH
with a :
to be made explicit with a relative or absolute path, for example:
`/path/to/file:name.txt` or `./file:name.txt`
It is not possible to copy certain system files such as resources under /proc
, /sys
, /dev
, and mounts created by the user in the container.
Using -
as the first argument in place of a LOCALPATH
will stream the contents of STDIN
as a tar archive which will be extracted to the PATH
in the filesystem of the destination container. In this case, PATH
must specify a directory.
Using -
as the second argument in place of a LOCALPATH
will stream the contents of the resource from the source container as a tar archive to STDOUT
.
--help Print usage statement
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 cp
in your ~
(home) directory on the local host:
$ docker 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 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 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 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 /tmp
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 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 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.
April 2014, Originally compiled by William Henry (whenry at redhat dot com) based on docker.com source material and internal work. June 2014, updated by Sven Dowideit SvenDowideit@home.org.au May 2015, updated by Josh Hawn josh.hawn@docker.com