How to add the VirtualBox keyring to Debian and Ubuntu

This blog post explains how to add the Sun and Oracle VirtualBox keyring to Debian and Ubuntu, to prevent apt-get update from complaining.

If apt-get update gives you a warning with NO_PUBKEY 54422A4B98AB5139, then do this to fix it:

$ wget -q http://download.virtualbox.org/virtualbox/debian/sun_vbox.asc -O- |
  sudo apt-key add -
$ wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- |
  sudo apt-key add -
$ sudo apt-get update