Using yum to build chroot

yum chroot

mkdir /path/to/chroot
rpm --root /path/to/chroot --initdb
wget http://repo_url/centos-release-version.rpm
rpm -i --nodeps --root /path/to/chroot /path/to/centos-release-version.rpm

yum --installroot=/path/to/chroot --nogpgcheck install -y yum rpm-build
# -or-
yum --installroot=/path/to/chroot --nogpgcheck groupinstall -y Base

# to use yum inside the chroot
mount --bind /proc /path/to/chroot/proc
mount --bind /dev /path/to/chroot/dev