What is the recommended workflow for using docker? Say I have: * a base Ubuntu container with a few utilities installed like htop and my user account * a ba

What is the recommended workflow for using docker? Say I have: * a base Ubuntu container with a few utilities installed like htop and my user account * a base Python web container with Nginx and libxml, libjpeg, etc * a specific Python web app If I update my app should I save the container state and push it to all my web servers or use something like fabric to update the app on all my app servers? If Nginx has a security release and I update my base Python web container, do I now need to rebuild all my Python web containers or is there some way to merge? When the next LTS release of Ubuntu comes out and I upgrade, do I have to manually apply that to every container or just the base?