1907
votes

I am trying to build a backup and restore solution for the Docker containers that we work with.

I have Docker base image that I have created, ubuntu:base, and do not want have to rebuild it each time with a Docker file to add files to it.

I want to create a script that runs from the host machine and creates a new container using the ubuntu:base Docker image and then copies files into that container.

How can I copy files from the host to the container?

30
If you don't want to rebuild, why not "docker commit" ? That saves your image.Berend de Boer
Just a remark on a notion nobody has addressed: in general, treat containers as "ephemeral". There ARE use cases to copy files into/from a running container (testing, prototyping). But if you find yourself in a position where you can't rebuild what you need using Dockerfiles and/or compose, then you may be in a bad place. You generally don't want to be backing up containers as if they were OS or even VM objects. Generally speaking :-)Scott Prive
@BerenddeBoer's link is now outdated, here's the new URL: docs.docker.com/engine/reference/commandline/commitErin

30 Answers

3237
votes

The cp command can be used to copy files.

One specific file can be copied TO the container like:

docker cp foo.txt mycontainer:/foo.txt

One specific file can be copied FROM the container like:

docker cp mycontainer:/foo.txt foo.txt

For emphasis, mycontainer is a container ID, not an image ID.

Multiple files contained by the folder src can be copied into the target folder using:

docker cp src/. mycontainer:/target
docker cp mycontainer:/src/. target

Reference: Docker CLI docs for cp

In Docker versions prior to 1.8 it was only possible to copy files from a container to the host. Not from the host to a container.

201
votes
  1. Get container name or short container id:

    $ docker ps
    
  2. Get full container id:

    $ docker inspect -f   '{{.Id}}'  SHORT_CONTAINER_ID-or-CONTAINER_NAME
    
  3. Copy file:

    $ sudo cp path-file-host /var/lib/docker/aufs/mnt/FULL_CONTAINER_ID/PATH-NEW-FILE
    

EXAMPLE:

$ docker ps

CONTAINER ID      IMAGE    COMMAND       CREATED      STATUS       PORTS        NAMES

d8e703d7e303   solidleon/ssh:latest      /usr/sbin/sshd -D                      cranky_pare

$ docker inspect -f   '{{.Id}}' cranky_pare

or

$ docker inspect -f   '{{.Id}}' d8e703d7e303

d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5

$ sudo cp file.txt /var/lib/docker/aufs/mnt/**d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5**/root/file.txt
153
votes

The cleanest way is to mount a host directory on the container when starting the container:

{host} docker run -v /path/to/hostdir:/mnt --name my_container my_image
{host} docker exec -it my_container bash
{container} cp /mnt/sourcefile /path/to/destfile
122
votes

The following is a fairly ugly way of doing it but it works.

docker run -i ubuntu /bin/bash -c 'cat > file' < file
48
votes

If you need to do this on a running container you can use docker exec (added in 1.3).

First, find the container's name or ID:

$ docker ps
CONTAINER ID        IMAGE                        COMMAND             CREATED             STATUS              PORTS                   NAMES
b9b7400ddd8f        ubuntu:latest                "/bin/bash"         2 seconds ago       Up 2 seconds                                elated_hodgkin

In the example above we can either use b9b7400ddd8f or elated_hodgkin.

If you wanted to copy everything in /tmp/somefiles on the host to /var/www in the container:

$ cd /tmp/somefiles
$ tar -cv * | docker exec -i elated_hodgkin tar x -C /var/www

We can then exec /bin/bash in the container and verify it worked:

$ docker exec -it elated_hodgkin /bin/bash
root@b9b7400ddd8f:/# ls /var/www
file1  file2
48
votes

Typically there are three types:

  1. From a container to the host

    docker cp container_id:./bar/foo.txt .
    

dev1

  1. From the host to a container

    docker exec -i container_id sh -c 'cat > ./bar/foo.txt' < ./foo.txt
    
  2. Second approach to copy from host to container:

    docker cp foo.txt mycontainer:/foo.txt
    

dev2

  1. From a container to a container mixes 1 and 2

    docker cp container_id1:./bar/foo.txt .
    
    docker exec -i container_id2 sh -c 'cat > ./bar/foo.txt' < ./foo.txt
    

dev3

43
votes
  1. Create a new dockerfile and use the existing image as your base.

    FROM myName/myImage:latest
    
    ADD myFile.py bin/myFile.py
    
  2. Then build the container:

    docker build .
    
41
votes

The solution is given below,

From the Docker shell,

root@123abc:/root#  <-- get the container ID

From the host

cp thefile.txt /var/lib/docker/devicemapper/mnt/123abc<bunch-o-hex>/rootfs/root

The file shall be directly copied to the location where the container sits on the filesystem.

33
votes

Another solution for copying files into a running container is using tar:

tar -c foo.sh | docker exec -i theDockerContainer /bin/tar -C /tmp -x

Copies the file foo.sh into /tmp of the container.

Edit: Remove reduntant -f, thanks to Maartens comment.

24
votes

To copy a file from host to running container

docker exec -i $CONTAINER /bin/bash -c "cat > $CONTAINER_PATH" < $HOST_PATH

Based on Erik's answer and Mikl's and z0r's comments.

20
votes

This is a direct answer to the question 'Copying files from host to Docker container' raised in this question in the title.

Try docker cp. It is the easiest way to do that and works even on my Mac. Usage:

docker cp /root/some-file.txt some-docker-container:/root

This will copy the file some-file.txt in the directory /root on your host machine into the Docker container named some-docker-container into the directory /root. It is very close to the secure copy syntax. And as shown in the previous post, you can use it vice versa. I.e., you also copy files from the container to the host.

And before you downlink this post, please enter docker cp --help. Reading the documentation can be very helpful, sometimes...

If you don't like that way and you want data volumes in your already created and running container, then recreation is your only option today. See also How can I add a volume to an existing Docker container?.

18
votes

I tried most of the (upvoted) solutions here but in docker 17.09 (in 2018) there is no longer /var/lib/docker/aufs folder.

This simple docker cp solved this task.

docker cp c:\path\to\local\file container_name:/path/to/target/dir/

How to get container_name?

 docker ps 

There is a NAMES section. Don't use aIMAGE.

16
votes

With Docker 1.8, docker cp is able to copy files from host to container. See the Docker blog post Announcing Docker 1.8: Content Trust, Toolbox, and Updates to Registry and Orchestration.

14
votes

To copy files/folders between a container and the local filesystem, type the command:

docker cp {SOURCE_FILE} {DESTINATION_CONTAINER_ID}:/{DESTINATION_PATH}

For example,

docker cp /home/foo container-id:/home/dir

To get the contianer id, type the given command:

docker ps

The above content is taken from docker.com.

8
votes

Assuming the container is already running, type the given command:

# cat /path/to/host/file/ | docker exec -i -t <container_id> bash -c "/bin/cat > /path/to/container/file"

To share files using shared directory, run the container by typing the given command:

# docker run -v /path/to/host/dir:/path/to/container/dir ...

Note: Problems with permissions might arise as container's users are not the same as the host's users.

8
votes

This is the command to copy data from Docker to Host:

docker cp container_id:file path/filename /hostpath

docker cp a13fb9c9e674:/tmp/dgController.log /tmp/

Below is the command to copy data from host to docker:

docker cp a.txt ccfbeb35116b:/home/
7
votes

In a docker environment, all containers are found in the directory:

/var/lib/docker/aufs/required-docker-id/

To copy the source directory/file to any part of the container, type the given command:

sudo cp -r mydir/ /var/lib/docker/aufs/mnt/required-docker-id/mnt/

7
votes

Docker cp command is a handy utility that allows to copy files and folders between a container and the host system.

If you want to copy files from your host system to the container, you should use docker cp command like this:

docker cp host_source_path container:destination_path

List your running containers first using docker ps command:

abhishek@linuxhandbook:~$ sudo docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              
  PORTS               NAMES
  8353c6f43fba        775349758637        "bash"              8 seconds ago       Up 7 
  seconds                            ubu_container

You need to know either the container ID or the container name. In my case, the docker container name is ubu_container. and the container ID is 8353c6f43fba.

If you want to verify that the files have been copied successfully, you can enter your container in the following manner and then use regular Linux commands:

docker exec -it ubu_container bash

Copy files from host system to docker container Copying with docker cp is similar to the copy command in Linux.

I am going to copy a file named a.py to the home/dir1 directory in the container.

docker cp a.py ubu_container:/home/dir1

If the file is successfully copied, you won’t see any output on the screen. If the destination path doesn’t exist, you would see an error:

abhishek@linuxhandbook:~$ sudo docker cp a.txt ubu_container:/home/dir2/subsub
        Error: No such container:path: ubu_container:/home/dir2

If the destination file already exists, it will be overwritten without any warning.

You may also use container ID instead of the container name:

docker cp a.py 8353c6f43fba:/home/dir1
6
votes

If the host is CentOS or Fedora, there is a proxy NOT in /var/lib/docker/aufs, but it is under /proc:

cp -r /home/user/mydata/* /proc/$(docker inspect --format "{{.State.Pid}}" <containerid>)/root

This cmd will copy all contents of data directory to / of container with id "containerid".

5
votes

tar and docker cp are a good combo for copying everything in a directory.

Create a data volume container

docker create --name dvc --volume /path/on/container cirros

To preserve the directory hierarchy

tar -c -C /path/on/local/machine . | docker cp - dvc:/path/on/container

Check your work

docker run --rm --volumes-from dvc cirros ls -al /path/on/container
5
votes

In case it is not clear to someone like me what mycontainer in @h3nrik answer means, it is actually the container id. To copy a file WarpSquare.mp4 in /app/example_scenes/1440p60 from an exited docker container to current folder I used this.

docker cp `docker ps -q -l`:/app/example_scenes/1440p60/WarpSquare.mp4 .

where docker ps -q -l pulls up the container id of the last exited instance. In case it is not an exited container you can get it by docker container ls or docker ps

5
votes
docker cp SRC_PATH CONTAINER_ID:DEST_PATH

For example, I want to copy my file xxxx/download/jenkins to tomcat

I start to get the id of the container Tomcat

docker ps

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                    NAMES
63686740b488        tomcat              "catalina.sh run"   12 seconds ago      Up 11 seconds       0.0.0.0:8080->8080/tcp   peaceful_babbage

docker cp xxxx/download/jenkins.war  63686740b488:usr/local/tomcat/webapps/
5
votes

Container Up Syntax:

docker run -v /HOST/folder:/Container/floder 

In docker File

COPY hom* /myFolder/        # adds all files starting with "hom"
COPY hom?.txt /myFolder/    # ? is replaced with any single character, e.g., "home.txt"
4
votes

Many that find this question may actually have the problem of copying files into a Docker image while it is being created (I did).

In that case, you can use the COPY command in the Dockerfile that you use to create the image.

See the documentation.

4
votes

You can just trace the IP address of your local machine using

ifconfig

Then just enter into your Docker container and type

scp user_name@ip_address:/path_to_the_file destination

In any case if you don't have an SSH client and server installed, just install it using:

sudo apt-get install openssh-server
4
votes

This is a onliner for copying a single file while running a tomcat container.

docker run -v /PATH_TO_WAR/sample.war:/usr/local/tomcat/webapps/myapp.war -it -p 8080:8080 tomcat

This will copy the war file to webapps directory and get your app running in no time.

3
votes

The best way for copying files to the container I found is mounting a directory on host using -v option of docker run command.

3
votes

There are good answers, but too specific. I find out docker ps is good way to get container id you're interested in. Then do

mount | grep <id>

to see where the volume is mounted. That's

/var/lib/docker/devicemapper/mnt/<id>/rootfs/

for me, but it might be a different path depending on the OS and configuration. Now simply copy files to that path.

Using -v is not always practical.

3
votes

I just started using docker to compile VLC, here's what you can do to copy files back and forth from containers:

su -
cd /var/lib/docker
ls -palR > /home/user/dockerfilelist.txt

Search for a familiar file in that txt and you'll have the folder, cd to it as root and voila! copy all you want.

There might be a path with "merged" in it, I guess you want the one with "diff" in it.

Also if you exit the container and want to be back where you left off:

docker ps -a
docker start -i containerid

I guess that's usefull when you didn't name anything with a command like

docker run -it registry.videolan.org:5000/vlc-debian-win64 /bin/bash

Sure the hacker method but so what!

2
votes

My favorite method:

CONTAINERS:

CONTAINER_ID=$(docker ps | grep <string> | awk '{ print $1 }' | xargs docker inspect -f '{{.Id}}')

file.txt

mv -f file.txt /var/lib/docker/devicemapper/mnt/$CONTAINER_ID/rootfs/root/file.txt

or

mv -f file.txt /var/lib/docker/aufs/mnt/$CONTAINER_ID/rootfs/root/file.txt