The docker export and docker commit commands do not save the container volumes. Use this script to save and load the container volumes.
docker-volumes.sh [-v|--verbose] CONTAINER [save|load] TARBALL
Let's migrate a container to another host with all its volumes.
# Stop the container
docker stop $CONTAINER
# Create a new image
docker commit $CONTAINER $CONTAINER
# Save and load image to another host
docker save $CONTAINER | ssh $USER@$HOST docker load
# Save the volumes (use ".tar.gz" if you want compression)
docker-volumes.sh $CONTAINER save $CONTAINER-volumes.tar
# Copy volumes to another host
scp $CONTAINER-volumes.tar $USER@$HOST:
### On the other host:
# Create container with the same options used in the previous container
docker create --name $CONTAINER [<PREVIOUS CONTAINER OPTIONS>] $CONTAINER
# Load the volumes
docker-volumes.sh $CONTAINER load $CONTAINER-volumes.tar
# Start container
docker start $CONTAINER
- This script could have been written in Python or Go, but the tarfile module and the tar package lack support for writing sparse files.
- We use the Ubuntu 18.04 Docker image with GNU tar v1.29 that uses SEEK_DATA/SEEK_HOLE to manage sparse files.
- To see the volumes that would be processed run
docker container inspect -f '{{json .Mounts}}' $CONTAINER
and pipe it to eitherjq
orpython -m json.tool
.