docker rootfs defaults

make-rootfs.sh

@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+log() {
+  printf '[make-rootfs] %s\n' "$*"
+}
+
+usage() {
+  cat <<'EOF'
+Usage: ./make-rootfs.sh [--size <size>] [--base-rootfs <path>]
+
+Builds rootfs-docker.ext4 using customize.sh. If --base-rootfs is omitted,
+the first existing file is used:
+  ./rootfs.ext4
+  ./ubuntu-noble-rootfs/rootfs.ext4
+  ./ubuntu-lts/rootfs.ext4
+EOF
+}
+
+DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+OUT_ROOTFS="$DIR/rootfs-docker.ext4"
+SIZE_SPEC="6G"
+BASE_ROOTFS=""
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --size)
+      SIZE_SPEC="${2:-}"
+      shift 2
+      ;;
+    --base-rootfs)
+      BASE_ROOTFS="${2:-}"
+      shift 2
+      ;;
+    -h|--help)
+      usage
+      exit 0
+      ;;
+    *)
+      log "unknown option: $1"
+      usage
+      exit 1
+      ;;
+  esac
+done
+
+if [[ -f "$OUT_ROOTFS" ]]; then
+  log "already exists: $OUT_ROOTFS"
+  exit 0
+fi
+
+if [[ -z "$BASE_ROOTFS" ]]; then
+  if [[ -f "$DIR/rootfs.ext4" ]]; then
+    BASE_ROOTFS="$DIR/rootfs.ext4"
+  elif [[ -f "$DIR/ubuntu-noble-rootfs/rootfs.ext4" ]]; then
+    BASE_ROOTFS="$DIR/ubuntu-noble-rootfs/rootfs.ext4"
+  elif [[ -f "$DIR/ubuntu-lts/rootfs.ext4" ]]; then
+    BASE_ROOTFS="$DIR/ubuntu-lts/rootfs.ext4"
+  else
+    log "no base rootfs found"
+    exit 1
+  fi
+fi
+
+log "building $OUT_ROOTFS from $BASE_ROOTFS"
+exec "$DIR/customize.sh" "$OUT_ROOTFS" \
+  --size "$SIZE_SPEC" \
+  --base-rootfs "$BASE_ROOTFS" \
+  --docker