if [ -f $target/etc/apt/sources.list -a -n "$release" ]; then
grep -q 'file generated by fai-cd' $target/etc/apt/sources.list && cat <<EOF > $target/etc/apt/sources.list
deb $apt_cdn/debian $release main contrib non-free
if [ -f $target/etc/apt/sources.list -a -n "$release" ]; then
grep -q 'file generated by fai-cd' $target/etc/apt/sources.list && cat <<EOF > $target/etc/apt/sources.list
deb $apt_cdn/debian $release main contrib non-free