Add helper to rebake iso with config

tools-image/add-cloud-init.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# docker run --entrypoint /add-cloud-init.sh -v $PWD:/work -ti --rm test https://github.com/kairos-io/kairos/releases/download/v1.1.2/kairos-alpine-v1.1.2.iso /work/test.iso /work/config.yaml
+
+set -ex
+
+ISO=$1
+OUT=$2
+CONFIG=$3
+
+case ${ISO} in
+http*)
+    curl -L "${ISO}" -o in.iso
+    ISO=in.iso
+    ;;
+esac
+
+# Needs xorriso >=1.5.4
+xorriso -indev $ISO -outdev $OUT -map $CONFIG /config.yaml -boot_image any replay