Change needed to add header blocks to all Dockerfiles, similar to the
base.
Use case is to easily run something before packages are installed, e.g.
to COPY a local rpm in that can be added to the package list.
Change-Id: I1bbfdf0b762da0a392aa8bf47781315b45377bee
Closes-Bug: 1618969
nova-spicehtml5proxy service fails on RPM-based systems unless the
spice-html5 RPM is also installed.
Change-Id: I0807159cd68bcc9df4da2d94d7b54a2871236f59
Closes-Bug: #1587212
Updates to ensure commands run in the nova containers
are done as the 'nova' user rather than root.
Change-Id: I0dd0276c2848ad77d92d350dfa0f20161329ed55
Partially-Implements: blueprint drop-root