Work in progress, these steps do not work.

Create a persistent storage location for your images

sudo mkdir /mnt/docker

Download and run the docker registry image

docker run -d -p 5000:5000 -v /mnt/docker:/tmp/registry registry:2

Tag your images with your registry location

This will make a copy of the existing image with the new name.

docker tag <ImageId> <hostname>:<port>/<image_name>:<tag>

Push your images to the registry

docker push localhost:5000/mywebapp