Autodetect incus/lxd unless specific YNHDEV_BACKEND

lib/common.sh

@@ -33,9 +33,9 @@ assert_we_are_connected_to_the_internets() {
 
 assert_we_have_all_dependencies() {
     deps=("lynx" "jq" "python3" "pip3")
-    if [[ "${YNHDEV_BACKEND:-}" == "incus" ]]; then
+    if [[ "${lxc}" == "incus" ]]; then
         deps+=(incus)
-    else
+    elif [[ "${lxc}" == "lxc" ]]; then
         deps+=(lxc lxd)
     fi
 
@@ -87,7 +87,7 @@ function set_incus_remote()
 
 function check_lxc_setup()
 {
-    if [[ "${YNHDEV_BACKEND:-}" == "incus" ]]; then
+    if [[ "${lxc}" == "incus" ]]; then
         check_incus_setup
     else
         check_lxd_setup

lib/lxc.sh

@@ -3,10 +3,15 @@
 # Check for LXC or Incus
 function switch_lxc_incus()
 {
-    if [[ "${YNHDEV_BACKEND:-}" == "incus" ]]; then
-        lxc=incus
+    if [[ -z "${YNHDEV_BACKEND:-}" ]]; then
+        # Autodetect because no preference was specified
+        if command -v incus 2>&1 >/dev/null; then
+            lxc="incus"
         else
-        lxc=lxc
+            lxc="lxc"
+        fi
+    else
+        lxc="${YNHDEV_BACKEND}"
     fi
 }
 

package_check.sh

@@ -24,7 +24,7 @@ print_help() {
     -S, --storage-dir DIRECTORY Where to store temporary test files like yunohost backups
     -h, --help                  Display this help
 
-    Pass YNHDEV_BACKEND=incus to use incus instead of lxd.
+    Pass YNHDEV_BACKEND=incus|lxd to use a specific LXD-compatible backend.
 
 EOF
 exit 0