These are now based on https://github.com/rhinstaller/lorax/pull/8
rpm-ostree-toolbox always uses this code path now; we spawn an "ostree trivial-httpd" even for local use. That way the same template can be used for both remote repositories and local ones.
This is migrated from https://github.com/projectatomic/rpm-ostree-toolbox/blob/master/src/py/lorax-embed-repo.tmpl It is a command template to embed content into the installer.