refactor: use bubble instead

image/overlay/daemon/update-keys.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+# VARIABLES: _REVISION_ _REPO_
+
+set -euo pipefail
+mkdir -p /users && chown keeper /users && chmod 644 /users
+
+su keeper
+
+init_repo(){ 
+    git clone -b _REVISION_ _REPO_ /users
+}
+
+if [[ ! -d /users/.git ]]; then
+    init_repo
+elif [[ -d /users && cd /users && ! git pull origin _REVISION_ ]]; then
+    init_repo
+fi