Remove option to use Rugged from WriteRef RPC
Today, Gitaly mostly uses git update-ref
to update refs except in the WriteRef RPC, where we have an explicit option in the RPC to use Rugged (libgit2) instead.
We have had an issue with libgit2 ref updates in the past where the conclusion was that git update-ref
is safer. But we never fully eliminated the use of libgit2 ref updates from the application (in part because prior to Gitaly it was hard to enforce discipline on this sort of thing).
Considering that there is now a new issue where libgit2 ref updates are suspected of failing in a bad way, it would perhaps make sense to change WriteRef so it can no longer use libgit2.