% 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`, tmpfs, and mounts created by the user in the container. However, you can still copy such files by manually running `tar` in `docker exec`. For example (consider `SRC_PATH` and `DEST_PATH` are directories): $ docker exec foo tar Ccf $(dirname SRC_PATH) - $(basename SRC_PATH) | tar Cxf DEST_PATH - or $ tar Ccf $(dirname SRC_PATH) - $(basename SRC_PATH) | docker exec -i foo tar Cxf DEST_PATH - 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 <SvenDowideit@home.org.au> May 2015, updated by Josh Hawn <josh.hawn@docker.com>