Aegir is a very clever Drupal hosting system built using Drupal and Drush. It is divided into two parts: the frontend and the backend. The frontend is essentially just a standard Drupal site that stores its data in the database and then some drush scripts that manipulate the data. The backend (provision) is just a collection of drush scripts, and it stores its data in Aegir contexts which are essentially just arrays of data stored in text files on disk. One of the most mysterious processes in Aegir is sending data from the frontend to the backend to be stored in these contexts. Recently I cracked this mystery, and I'm going to explain how.