The 'None' Datasource does not exist in precise 12.04 (which uses
cloud-init 0.6.3), so conditionally ensure that we are not including
this in the datasource_list in case we're building a precise image.
Partial-bug: 1329068
Change-Id: I6efb91e17bf896bbf7d67c31c4eb5098d5d61a71
This moves cloud-init data source configuration to a general purpose
cloud-init-datasources element that can be used to explicitly configure
the list of cloud-init sources that will be queried on first boot.
cloud-init-nocloud now depends on this new element to configure the
datasource_list while continuing to prep the image for a nocloud first boot.
Change-Id: Ibcc3b86d6ca567a23f89b7a1a36bc713e444ef68
Closes-bug: #1316475