customize base rootfs arg

customize.sh

@@ -7,7 +7,7 @@ log() {
 
 usage() {
   cat <<'EOF'
-Usage: ./customize.sh <output-rootfs> [--size <size>] [--base-rootfs <path>] [--kernel <path>] [--initrd <path>] [--docker] [--modules <dir>]
+Usage: ./customize.sh <base-rootfs> [--out <path>] [--size <size>] [--kernel <path>] [--initrd <path>] [--docker] [--modules <dir>]
 
 Creates a copy of rootfs.ext4, optionally resizes it, boots a VM using the
 copy as a writable rootfs, then applies base configuration and packages.
@@ -46,18 +46,19 @@ BR_IP="172.16.0.1"
 CIDR="24"
 DNS_SERVER="1.1.1.1"
 
+BASE_ROOTFS=""
 OUT_ROOTFS=""
 SIZE_SPEC=""
 INSTALL_DOCKER=0
 MODULES_DIR="$DIR/wtf/root/lib/modules/6.8.0-94-generic"
 while [[ $# -gt 0 ]]; do
   case "$1" in
-    --size)
-      SIZE_SPEC="${2:-}"
+    --out)
+      OUT_ROOTFS="${2:-}"
       shift 2
       ;;
-    --base-rootfs)
-      BASE_ROOTFS="${2:-}"
+    --size)
+      SIZE_SPEC="${2:-}"
       shift 2
       ;;
     --kernel)
@@ -81,8 +82,8 @@ while [[ $# -gt 0 ]]; do
       exit 0
       ;;
     *)
-      if [[ -z "$OUT_ROOTFS" ]]; then
-        OUT_ROOTFS="$1"
+      if [[ -z "$BASE_ROOTFS" ]]; then
+        BASE_ROOTFS="$1"
         shift
       else
         log "unknown option: $1"
@@ -93,7 +94,7 @@ while [[ $# -gt 0 ]]; do
   esac
 done
 
-if [[ -z "$OUT_ROOTFS" ]]; then
+if [[ -z "$BASE_ROOTFS" ]]; then
   usage
   exit 1
 fi
@@ -102,6 +103,12 @@ if [[ ! -f "$BASE_ROOTFS" ]]; then
   log "base rootfs not found: $BASE_ROOTFS"
   exit 1
 fi
+
+if [[ -z "$OUT_ROOTFS" ]]; then
+  base_dir="$(dirname "$BASE_ROOTFS")"
+  base_name="$(basename "$BASE_ROOTFS")"
+  OUT_ROOTFS="${base_dir}/docker-${base_name}"
+fi
 if [[ ! -f "$KERNEL" ]]; then
   log "kernel not found: $KERNEL"
   exit 1