Robert Collins d7379df8b8 Enable --offline support for Ubuntu root images.
When --offline is set elements should not revalidate cached data. The
ubuntu element had not been updated to match this. SHA checking is
also skipped as we only move a new cached file into place when the
hash matches, and we might download a new hash before updating the
image cache, which would cause persistent --offline failures.

Change-Id: If1a0366b51951a73b7a3ffe23a29a3d910b08938
2013-07-18 13:19:35 +12:00
..

Use Ubuntu cloud images as the baseline for built disk images.

Overrides:

  • To use a non-default URL for downloading base Ubuntu cloud images, use the environment variable DIB_CLOUD_IMAGES
  • To download a non-default release of Ubuntu cloud images, use the environment variable DIB_RELEASE