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+This role is for the (currently single) server that performs
+rpm-ostree tree composes.  It takes as input two primary data sets:
+
+1) The Fedora package set for a particular branch (f21, rawhide)
+2) A git repository, https://git.fedorahosted.org/cgit/fedora-atomic.git
+
+This output gets written into an OSTree repository which is pushed to:
+http://dl.fedoraproject.org/pub/fedora/linux/atomic/
+
+This is only for Fedora 21.  rawhide trees are handled via
+https://git.fedorahosted.org/cgit/releng/tree/scripts/run-pungi
+
+It uses lmacken's
+
+https://github.com/fedora-infra/fedmsg-atomic-composer
+
+which has the ability to listen for fedmsg notifications of package
+set changes, but is not actually doing so at the moment due to
+concerns about fedmsg reliability (?).
+