add live_system config option

This is to be used in environments where reboot is strictly unneeded;
such as when building packages in a chroot

bin/sau

@@ -115,6 +115,9 @@ def main():
         log.error(f'Upgrade failed: {e}')
         return 1
 
+    if not conf.getboolean('default', 'live_system', True):
+        return 0
+
     if conf.getboolean('default', 'do_service_restart', fallback=True):
         reboot_recommended = sau.services.restart_services()
 

config.cfg

@@ -12,6 +12,10 @@
 # 1.0.1 -> 1.0.1.1 (3)
 version_sensitivity=1
 
+# Set to no if you're using sau in an environment where running processes
+# shouldn't be touched and reboots shouldn't be done, for example in chroots
+live_system=yes
+
 # sau can reboot on system upgrades (FreeBSD) or if the service restarts does
 # not close all deleted files (any platform)
 do_reboot=no