centos-release-gluster9 provides the YUM repository file for the CentOS Storage SIG that provide GlusterFS 9.
This package needs to get built against the following targets so that the packages land at the right tag for inclusion in CentOS Extras:
Building the package can be done like this:
$ rpmbuild -bs \
--define "_sourcedir $PWD/SOURCES" --define "_srcrpmdir $PWD" \
--define "dist .el7.centos" \
SPECS/centos-release-gluster9.spec
$ cbs build core7-extras-common-el7.centos \
centos-release-gluster9-0.1-1.el7.centos.src.rpm