Provide an exit code when raising SystemExit.

This will make it easier for scripts which call OpenStack tools to
detect failure if SystemExit isn't caught by the calling code.

Change-Id: Ic829b704d1629fcb0d926118367af122c25b7fba

oslo_config/cfg.py

@@ -2990,7 +2990,7 @@ class ConfigOpts(abc.Mapping):
             except ValueError:
                 sys.stderr.write("argument --%s: Invalid %s value: %s\n" % (
                     opt.dest, repr(opt.type), value))
-                raise SystemExit
+                raise SystemExit(1)
 
     def _reload_config_files(self):
         namespace = self._parse_config_files()

oslo_config/generator.py

@@ -826,7 +826,7 @@ def main(args=None):
     except cfg.RequiredOptError:
         conf.print_help()
         if not sys.argv[1:]:
-            raise SystemExit
+            raise SystemExit(1)
         raise
     generate(conf)
 

oslo_config/validator.py

@@ -227,7 +227,7 @@ def main():
     except cfg.RequiredOptError:
         conf.print_help()
         if not sys.argv[1:]:
-            raise SystemExit
+            raise SystemExit(1)
         raise
     return _validate(conf)