2a14088eac
This makes the container file element search the active element list
for `containerfiles/${DIB_RELEASE}` for building. This makes it easy
to write wrappers for ubuntu/fedora/etc. containerfile elements.
Change-Id: I68f1d928e54a70bad76985ddd3e156bb5f978b0d
containerfile
Base element for creating images from container files (aka Dockerfiles).
Usually this element will be called via a more specific distro element which provides an environment for building a full image. This element will search active elements for a container file located in containerfiles/${DIB_RELEASE}.
Alternatively, to use this element directly supply the path to a container file in the environment variable DIB_CONTAINER_FILE.