% DOCKER(1) Docker User Manuals % Docker Community % JUNE 2014 # NAME docker-cp - Copy files/folders between a container and the local filesystem. # SYNOPSIS **docker cp** [**--help**] CONTAINER:SRC_PATH DEST_PATH|- **docker cp** [**--help**] SRC_PATH|- CONTAINER:DEST_PATH # DESCRIPTION The `docker cp` utility copies the contents of `SRC_PATH` to the `DEST_PATH`. You can copy from the container's file system 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 `docker cp` command assumes container paths are relative to the container's `/` (root) directory. 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 `docker cp` is run. The `cp` command behaves like the Unix `cp -a` command in that directories are copied recursively with permissions preserved if possible. Ownership is set to the user and primary group at the destination. For example, files copied to a container are created with `UID:GID` of the root user. Files copied to the local machine are created with the `UID:GID` of the user which invoked the `docker cp` command. If you specify the `-L` option, `docker cp` follows any symbolic link in the `SRC_PATH`. `docker cp` does *not* create parent directories for `DEST_PATH` if they do not exist. 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` - `DEST_PATH` does not exist and ends with `/` - Error condition: the destination 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` does not end with `/.` - the source directory is copied into this directory - `SRC_PATH` does end with `/.` - 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 link, not the target, is copied by default. To copy the link target and not the link, specify the `-L` option. 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` 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 `SRC_PATH` streams the contents of `STDIN` as a tar archive. The command extracts the content of the tar to the `DEST_PATH` in container's filesystem. In this case, `DEST_PATH` must specify a directory. Using `-` as the `DEST_PATH` streams the contents of the resource as a tar archive to `STDOUT`. # OPTIONS **-L**, **--follow-link**=*true*|*false* Follow symbol link in SRC_PATH **--help** Print usage statement # 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 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 `/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 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. 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 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. # HISTORY 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 May 2015, updated by Josh Hawn