add expand-rootfs.service to be installed on the image

includes/post/expand-rootfs.ksi

@@ -4,7 +4,9 @@ set -x
 # The script that expands root partition
 [ -d /usr/local/bin ] || mkdir --verbose /usr/local/bin
 curl 'https://git.resf.org/thefossguy/sbc-images/raw/branch/rocky-generic/scripts/expand-rootfs.sh' --output /usr/local/bin/expand-rootfs.sh || exit 1
+curl 'https://git.resf.org/thefossguy/sbc-images/raw/branch/rocky-generic/scripts/expand-rootfs.service' --output /etc/systemd/system/expand-rootfs.service || exit 1
 [ -f /usr/local/bin/expand-rootfs.sh ] && \
     chmod --verbose +x /usr/local/bin/expand-rootfs.sh
+systemctl enable expand-rootfs.service
 
 %end

scripts/expand-rootfs.service

@@ -0,0 +1,10 @@
+[Unit]
+Description=Expand root filesystem
+
+[Service]
+ExecStart=$(command -v bash) /usr/local/bin/expand-rootfs.sh
+Type=oneshot
+User=root
+
+[Install]
+WantedBy=default.target

scripts/expand-rootfs.sh

@@ -18,5 +18,12 @@ else
     exit 1
 fi
 
-growpart "${PARENT_ROOT_DEVICE}" "${ROOT_PARTITION}"
-resize2fs "${ROOT_DEVICE}"
+growpart "${PARENT_ROOT_DEVICE}" "${ROOT_PARTITION}" && GP_OK='true'
+resize2fs "${ROOT_DEVICE}" && RESIZE_OK='true'
+
+if [[ "${GP_OK}" == 'true' && "${RESIZE_OK}" == 'true' ]]; then
+    systemctl disable expand-rootfs.service
+    rm /etc/systemd/system/expand-rootfs.service
+    systemctl daemon-reload
+    rm /usr/local/bin/expand-rootfs.sh
+fi