scripts: Arch dependant repo url for fedora

Changed rootfs-builder/fedora/rootfs_lib.sh to select
repo URL based on arch.

Fixes #21.

Signed-off-by: Harshal Patil <harshal.patil@in.ibm.com>

rootfs-builder/fedora/Dockerfile

@@ -1,3 +1,3 @@
 From fedora:27
 
-RUN dnf -y update && dnf install -y git golang  systemd pkgconfig
+RUN dnf -y update && dnf install -y git golang redhat-release systemd pkgconfig

rootfs-builder/fedora/rootfs_lib.sh

@@ -28,9 +28,9 @@ installonly_limit=3
 reposdir=/root/mash
 
 [kata]
-name=fedora
+name=Fedora \$releasever - \$basearch
 failovermethod=priority
-baseurl=${REPO_URL}
+metalink=https://mirrors.fedoraproject.org/metalink?repo=fedora-\$releasever&arch=\$basearch
 enabled=1
 gpgcheck=0
 EOF
@@ -41,10 +41,6 @@ build_rootfs()
 	# Mandatory
 	local ROOTFS_DIR=$1
 
-	#In case rootfs is created usig repositories allow user to modify
-	# the default URL
-	local REPO_URL=${REPO_URL:-http://mirror.math.princeton.edu/pub/fedora/linux/releases/$OS_VERSION/Everything/x86_64/os/}
-
 	# In case of support EXTRA packages, use it to allow
 	# users add more packages to the base rootfs
 	local EXTRA_PKGS=${EXTRA_PKGS:-""}
@@ -70,8 +66,6 @@ build_rootfs()
 		die "neither yum nor dnf is installed"
 	fi
 
-	info "Using : ${PKG_MANAGER} to pull packages from ${REPO_URL}"
-
 	DNF="${PKG_MANAGER} --config=$DNF_CONF -y --installroot=${ROOTFS_DIR} --noplugins"
 	$DNF install ${EXTRA_PKGS} ${PACKAGES}