image / create_chroot - support OS images that are compressed with xz

Image files for Raspberry Pi OS buster (oldstable) and bulleye are now single files compressed with .xz instead of the zip files used previously.

Add support for decompressing xz as well as an additional check to make sure the image was extracted ok before continuing. Added return codes to the function.

Author: joolswills

scriptmodules/admin/image.sh

@@ -15,7 +15,7 @@ rp_module_section=""
 rp_module_flags=""
 
 function depends_image() {
-    local depends=(kpartx unzip binfmt-support rsync parted squashfs-tools dosfstools e2fsprogs)
+    local depends=(kpartx unzip binfmt-support rsync parted squashfs-tools dosfstools e2fsprogs xz-utils)
     isPlatform "x86" && depends+=(qemu-user-static)
     getDepends "${depends[@]}"
 }
@@ -34,12 +34,15 @@ function create_chroot_image() {
 
     local url
     local image
+    local fmt=".img.xz"
     case "$dist" in
         jessie)
             url="https://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2017-07-05/2017-07-05-raspbian-jessie-lite.zip"
+            fmt=".zip"
             ;;
         stretch)
             url="https://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2019-04-09/2019-04-08-raspbian-stretch-lite.zip"
+            fmt=".zip"
             ;;
         buster)
             url="https://downloads.raspberrypi.org/raspios_oldstable_lite_armhf_latest"
@@ -56,12 +59,24 @@ function create_chroot_image() {
     local base="raspbian-${dist}-lite"
     local image="$base.img"
     if [[ ! -f "$image" ]]; then
-        download "$url" "$base.zip"
-        unzip -o "$base.zip"
-        mv "$(unzip -Z -1 "$base.zip")" "$image"
-        rm "$base.zip"
+        local dest="$base$fmt"
+        case "$fmt" in
+            .zip)
+                download "$url" "$dest"
+                unzip -o "$dest"
+                mv "$(unzip -Z -1 "$dest")" "$image"
+                rm "$dest"
+                ;;
+            .img.xz)
+                download "$url" "$dest"
+                xz -d -v "$dest"
+                ;;
+        esac
     fi
 
+    # abort if there is no extracted image present
+    [[ ! -f "$image" ]] && return 1
+
     # mount image
     local partitions=($(kpartx -s -a -v "$image" | awk '{ print "/dev/mapper/"$3 }'))
     local part_boot="${partitions[0]}"
@@ -82,6 +97,7 @@ function create_chroot_image() {
     kpartx -d "$image"
 
     popd
+    return 0
 }
 
 function install_rp_image() {