What happens when I update something on Docker Hub?
This is a trivial Dockerfile to test out the linkage between a local registry and Docker Hub.
sudo docker run -it cpswan/testver will pull down the
:latest version from Docker Hub when it is first run.
Next time I run
sudo docker run -it cpswan/testver (or even
cpswan/testver:latest) docker will look in my local registry and find the image there.
If Docker Hub has been updated with a newer version then I have to explicitly
sudo docker pull cpswan/testver in order to get it.