Slightly simplify the build

alpine/build-rootfs.sh

@@ -4,6 +4,8 @@ set -euo pipefail
 
 /preload-k8s-images.sh || exit 1
 
+export CTL_BIN_LAYER=$( skopeo inspect docker-daemon:localhost/monok8s/control-agent:dev | jq -r '.Layers[0] | sub("^sha256:"; "")' )
+
 mkdir -p "$ROOTFS/var/cache/apk"
 mkdir -p "$ROOTFS/opt/monok8s/config"
 mkdir -p "$ROOTFS/build"
@@ -25,7 +27,6 @@ mount --bind /run  "$ROOTFS/run"
 cp /usr/bin/qemu-aarch64-static "$ROOTFS/usr/bin/"
 cp /etc/resolv.conf "$ROOTFS/etc/resolv.conf"
 cp /build/crio.tar.gz "$ROOTFS/build/"
-cp -r /build/rootfs/* "$ROOTFS/"
 
 chroot "$ROOTFS" /bin/sh -c "ln -s /var/cache/apk /etc/apk/cache"
 # chroot "$ROOTFS" /bin/sh -c "apk update"