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?
This question is related to
docker
docker-container
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
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
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.
I simply copy the file directly from where the container is located from the host machine.
For example:
First find out the container id:
root@**3aed62678d54**:/home#
And then from the host, let's say the file is in the home directory:
root@saasdock:/home/dnepangue# cp cheering_nasa.gif /var/lib/docker/aufs/mnt/**3aed62678d54**a5df47a4a00a58bb0312009c2902f8a37498a1427052e8ac454b/home/
Back to the container...
root@**3aed62678d54**:/home# ls cheering_nasa.gif
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/
The simpliest way to achieve this is,
docker cp <filename> <container-id>:<path>
Another workaround is using the good old scp
. This is useful in the case you need to copy a directory.
From your host run:
scp FILE_PATH_ON_YOUR_HOST IP_CONTAINER:DESTINATION_PATH
scp foo.txt 172.17.0.2:foo.txt
In the case you need to copy a directory:
scp -r DIR_PATH_ON_YOUR_HOST IP_CONTAINER:DESTINATION_PATH
scp -r directory 172.17.0.2:directory
be sure to install ssh into your container too.
apt-get install openssh-server
The best way for copying files to the container I found is mounting a directory on host using -v
option of docker run command.
One thing which I tried and it worked
Once you spin up your docker container and if you create any file under that container; You can easily access that file from below location of your docker host:-
Try once!
Get container name or short container id:
$ docker ps
Get full container id:
$ docker inspect -f '{{.Id}}' SHORT_CONTAINER_ID-or-CONTAINER_NAME
Copy file:
$ sudo cp path-file-host /var/lib/docker/aufs/mnt/FULL_CONTAINER_ID/PATH-NEW-FILE
$ 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
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
Copy from container to host dir
docker cp [container-name/id]:./app/[index.js] index.js
(assume you have created a workdir /app in your dockerfile)
Copy from host to container
docker cp index.js [container-name/id]:./app/index.js
Where you don't have a directory defined as a volume in the Dockerfile, the /var/lib/docker/aufs/mnt// will work. But there are cases where the directory within the container is defined as a volume. In this case, the contents under aufs/mnt/*/ and the contents seen by the container are different.
You will need to inspect the container using docker inspect and then, look for volumes. There you will find a mention for something like /var/lib/docker/vfs/dir/fe940b... (the id). You will need to add/modify the files here instead of under aufs/mnt/*.
The confusing part is that the files also appear under /aufs/mnt/*. I spent quite a while scratching my head why changes here didn't work for me. Hope this helps someone.
I usually create python server using this command
python -m SimpleHTTPServer
in the particular directory and then just use wget to transfer file in the desired location in docker. I know it is not the best way to do it but I find it much easier.
If using Windows as host, you can use WinSCP to connect to Docker and transfer files through the GUI.
If on Linux, the scp
command would also work through the terminal.
My favorite method:
CONTAINER_ID=$(docker ps | grep <string> | awk '{ print $1 }' | xargs docker inspect -f '{{.Id}}')
mv -f file.txt /var/lib/docker/devicemapper/mnt/$CONTAINER_ID/rootfs/root/file.txt
or
mv -f file.txt /var/lib/docker/aufs/mnt/$CONTAINER_ID/rootfs/root/file.txt
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?.
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/
In my opinion you have not to copy files inside image but you can use GIT or SVN for your files and then set a volume synchronized with a local folder. Use a script while runing container who can check if data already exist in local folder if not copy it from GIT repository. That make your image very lightweight.
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/
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.
The following is a fairly ugly way of doing it but it works.
docker run -i ubuntu /bin/bash -c 'cat > file' < file
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
.
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.
Try docker cp
.
Usage:
docker cp CONTAINER:PATH HOSTPATH
It copies files/folders from PATH
to the HOSTPATH
.
real deal is:
docker volume create xdata
docker volume inspect xdata
so you see its mount poit dir.
just copy your stuff there
then
docker run --name=example1 --mount source=xdata,destination=/xdata -it yessa bash
where yessa
is image name
Typically there are three types:
From a container to the host
docker cp container_id:./bar/foo.txt .
From the host to a container
docker exec -i container_id sh -c 'cat > ./bar/foo.txt' < ./foo.txt
Second approach to copy from host to container:
docker cp foo.txt mycontainer:/foo.txt
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
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.
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.
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.
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.
I'd mount and then run the image with a daemon, just any as given here;
docker run -d -v /blah1/blah2:/mnt --name mntcontainer ubuntu /bin/sh -c "while true; do echo hello world; sleep 1; done"
then
docker exec -it mntcontainer bash
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
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.
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"
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
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/$(docker inspect --format "{{.State.Pid}}" <containerid>)/root
This cmd will copy all contents of data
directory to /
of container with id "containerid".
The solution is given below,
root@123abc:/root# <-- get the container ID
cp thefile.txt /var/lib/docker/devicemapper/mnt/123abc<bunch-o-hex>/rootfs/root
The file shall be directly copied to the location where the container sits on the filesystem.
Docker cp command is a handy utility that allows to copy files and folders between a container and the host system.
If you want to copy files from your host system to the container, you should use docker cp command like this:
docker cp host_source_path container:destination_path
List your running containers first using docker ps command:
abhishek@linuxhandbook:~$ 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
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!
Create a new dockerfile and use the existing image as your base.
FROM myName/myImage:latest
ADD myFile.py bin/myFile.py
Then build the container:
docker build .
Source: Stackoverflow.com