This session will be for brainstorming about adding extensions to Glance. We need to cover: * What exactly *is* an extension? Is an extension a truly optional component that can be switched on or off at-will? Must an extension always add to the Images API? Or can an extension change existing behaviour in a documented way? Or can an extension exist that does not modify the API in any way at all (think: transparent caching extension)? * Use cases for extensions * Possible implementation ideas for extensions * Where to put extensions? Where to document them?