cache-devstack
Pre-cache a range of things into CI images. This element uses the
source-repositories element to acquire files to be cached.
The standard cache location is /opt/cache/files.
A number of strategies are used to get the files to be cached.
We have a number of source-repository-* files for each
package package that should be cached into images.
extra-data.d/55-cache-devstack-repos goes through each
devstack branch and runs the tools/image_list.sh script to
dynamically build a list of files to cache as requested by devstack.
This is mostly virtual machine images, but also some other peripheral
packages.