proper return codes and warnings if reboot is required

bin/sau

@@ -45,8 +45,13 @@ def init():
     log.addHandler(handler)
 
 
-def fork_and_reboot():
+def fork_and_reboot(report_success=True):
     log = logging.getLogger(sau.LOGNAME)
+    if report_success:
+        exit_code=0
+    else:
+        exit_code=1
+
     if os.path.exists('/proc/1/comm'):
         with open('/proc/1/comm', 'r') as f:
             if f.readline().strip() == 'systemd':
@@ -56,7 +61,7 @@ def fork_and_reboot():
     try:
         pid = os.fork()
         if pid != 0:
-            sys.exit(0)
+            sys.exit(exit_code)
     except OSError as err:
         log.error("Fork #1 failed when going for reboot: {}".format(err))
         sys.exit(1)
@@ -83,8 +88,6 @@ def fork_and_reboot():
     os.dup2(stdout.fileno(), sys.stdout.fileno())
     os.dup2(stderr.fileno(), sys.stderr.fileno())
 
-    log.warning("New fork!")
-
     # sleep for a short while to give parent time to exit
     time.sleep(30)
     try:
@@ -121,7 +124,16 @@ def main():
         elif reboot_recommended:
             log.info('Rebooting because service restarts did not close all deleted files')
         if reboot_required or reboot_recommended:
-            fork_and_reboot()
+            fork_and_reboot(report_success=conf.getboolean('default', 'reboot_is_success', Fallback=True))
+
+    if reboot_required:
+        log.warning("Upgrade was success, but a reboot is required due to a system upgrade")
+        return 1
+    elif reboot_recommended:
+        log.warning("Some services still uses old, deleted, files. You probably want to reboot")
+        return 1
+
+    return 0
 
 
 def _conf_level_to_logging_level(conf_level):

config.cfg

@@ -16,6 +16,9 @@ version_sensitivity=1
 # not close all deleted files (any platform)
 do_reboot=no
 
+# Set to 0 to exit with failure code when going for reboot.
+reboot_is_success=yes
+
 # Attempt to do a system upgrade
 # FreeBSD: upgrade to latest patch version using freebsd-update fetch install
 # Gentoo: allow upgrade of sys-kernel/-packages, clean old kernels, and update grub-config