Add --detailed-exit-codes

This patch adds a new --detailed-exit-codes option which can
be used to optionally enable the os-net-config CLI to return
exit code 2 if there have been modifications. Detailed
exit codes are useful if you need to trigger subsequent
external actions based whether os-net-config made changes or not.

Change-Id: I8f22fa15335d1276f4e444a6454a24ff486e1495

os_net_config/cli.py

@@ -48,6 +48,13 @@ def parse_opts(argv):
     parser.add_argument('-r', '--root-dir', metavar='ROOT_DIR',
                         help="""The root directory of the filesystem.""",
                         default='')
+    parser.add_argument('--detailed-exit-codes',
+                        action='store_true',
+                        help="""Enable detailed exit codes. """
+                        """If enabled an exit code of '2' means """
+                        """that files were modified."""
+                        """Disabled by default.""",
+                        default=False)
     parser.add_argument(
         '-d', '--debug',
         dest="debug",
@@ -183,6 +190,10 @@ def main(argv=sys.argv):
             print("File: %s\n" % location)
             print(data)
             print("----")
+
+    if opts.detailed_exit_codes and len(files_changed) > 0:
+        return 2
+
     return 0
 
 

os_net_config/tests/test_cli.py

@@ -17,7 +17,9 @@
 import os.path
 import sys
 
+import os_net_config
 from os_net_config import cli
+from os_net_config import impl_ifcfg
 from os_net_config.tests import base
 import six
 
@@ -121,3 +123,26 @@ class TestCli(base.TestCase):
                                                '-c %s' % (provider, bond_yaml))
             self.assertEqual('', stderr)
             self.assertIn('File: /rootfs/', stdout_yaml)
+
+    def test_interface_noop_detailed_exit_codes(self):
+        interface_yaml = os.path.join(SAMPLE_BASE, 'interface.yaml')
+        stdout_yaml, stderr = self.run_cli('ARG0 --provider=ifcfg --noop '
+                                           '-c %s --detailed-exit-codes'
+                                           % interface_yaml, exitcodes=(2,))
+
+    def test_interface_noop_detailed_exit_codes_no_changes(self):
+        interface_yaml = os.path.join(SAMPLE_BASE, 'interface.yaml')
+
+        class TestImpl(os_net_config.NetConfig):
+
+            def add_interface(self, interface):
+                pass
+
+            def apply(self, cleanup=False, activate=True):
+                # this fake implementation returns no changes
+                return {}
+
+        self.stubs.Set(impl_ifcfg, 'IfcfgNetConfig', TestImpl)
+        stdout_yaml, stderr = self.run_cli('ARG0 --provider=ifcfg --noop '
+                                           '-c %s --detailed-exit-codes'
+                                           % interface_yaml, exitcodes=(0,))