How to move Docker containers between different hosts?

Solution 1:

Alternatively, if you do not wish to push to a repository:

1. Export the container to a tarball

   docker export <CONTAINER ID> > /home/export.tar
   

2. Move your tarball to new machine

3. Import it back

   cat /home/export.tar | docker import - some-name:latest
   

Solution 2:

You cannot move a running docker container from one host to another.

You can commit the changes in your container to an image with docker commit, move the image onto a new host, and then start a new container with docker run. This will preserve any data that your application has created inside the container.

Nb: It does not preserve data that is stored inside volumes; you need to move data volumes manually to new host.

Solution 3:

What eventually worked for me, after lot's of confusing manuals and confusing tutorials, since Docker is obviously at time of my writing at peek of inflated expectations, is:

1. Save the docker image into archive:
   docker save image_name > image_name.tar
2. copy on another machine
3. on that other docker machine, run docker load in a following way:
   cat image_name.tar | docker load

Export and import, as proposed in another answers does not export ports and variables, which might be required for your container to run. And you might end up with stuff like "No command specified" etc... When you try to load it on another machine.

So, difference between save and export is that save command saves whole image with history and metadata, while export command exports only files structure (without history or metadata).

Needless to say is that, if you already have those ports taken on the docker hyper-visor you are doing import, by some other docker container, you will end-up in conflict, and you will have to reconfigure exposed ports.

Note: In order to move data with docker, you might be having persistent storage somewhere, which should also be moved alongside with containers.

Solution 4:

Use this script: https://github.com/ricardobranco777/docker-volumes.sh

This does preserve data in volumes.

Example usage:

# Stop the container   
docker stop $CONTAINER

# Create a new image   
docker commit $CONTAINER $CONTAINER

# Save image
docker save -o $CONTAINER.tar $CONTAINER

# Save the volumes (use ".tar.gz" if you want compression)
docker-volumes.sh $CONTAINER save $CONTAINER-volumes.tar

# Copy image and volumes to another host
scp $CONTAINER.tar $CONTAINER-volumes.tar $USER@$HOST:

# On the other host:
docker load -i $CONTAINER.tar
docker create --name $CONTAINER [<PREVIOUS CONTAINER OPTIONS>] $CONTAINER

# Load the volumes
docker-volumes.sh $CONTAINER load $CONTAINER-volumes.tar

# Start container
docker start $CONTAINER