Merge pull request #51706 from aplanas/fix_fqdns

grains/core: ignore HOST_NOT_FOUND errno in fqdns()

salt/grains/core.py

@@ -104,6 +104,10 @@ def linux_distribution(**kwargs):
 
 _INTERFACES = {}
 
+# Possible value for h_errno defined in netdb.h
+HOST_NOT_FOUND = 1
+NO_DATA = 4
+
 
 def _windows_cpudata():
     '''
@@ -2226,7 +2230,7 @@ def fqdns():
         try:
             fqdns.add(socket.getfqdn(socket.gethostbyaddr(ip)[0]))
         except socket.herror as err:
-            if err.errno == 0:
+            if err.errno in (0, HOST_NOT_FOUND, NO_DATA):
                 # No FQDN for this IP address, so we don't need to know this all the time.
                 log.debug("Unable to resolve address %s: %s", ip, err)
             else:

tests/unit/grains/test_core.py

@@ -1002,6 +1002,38 @@ def test_fqdns_return(self):
             self.assertEqual(len(fqdns['fqdns']), len(ret['fqdns']))
             self.assertEqual(set(fqdns['fqdns']), set(ret['fqdns']))
 
+    @skipIf(not salt.utils.platform.is_linux(), 'System is not Linux')
+    @patch.object(salt.utils, 'is_windows', MagicMock(return_value=False))
+    @patch('salt.utils.network.ip_addrs', MagicMock(return_value=['1.2.3.4']))
+    @patch('salt.utils.network.ip_addrs6', MagicMock(return_value=[]))
+    def test_fqdns_socket_error(self):
+        '''
+        test the behavior on non-critical socket errors of the dns grain
+        '''
+        def _gen_gethostbyaddr(errno):
+            def _gethostbyaddr(_):
+                herror = socket.herror()
+                herror.errno = errno
+                raise herror
+            return _gethostbyaddr
+
+        for errno in (0, core.HOST_NOT_FOUND, core.NO_DATA):
+            mock_log = MagicMock()
+            with patch.object(socket, 'gethostbyaddr',
+                              side_effect=_gen_gethostbyaddr(errno)):
+                with patch('salt.grains.core.log', mock_log):
+                    self.assertEqual(core.fqdns(), {'fqdns': []})
+                    mock_log.debug.assert_called_once()
+                    mock_log.error.assert_not_called()
+
+        mock_log = MagicMock()
+        with patch.object(socket, 'gethostbyaddr',
+                          side_effect=_gen_gethostbyaddr(-1)):
+            with patch('salt.grains.core.log', mock_log):
+                self.assertEqual(core.fqdns(), {'fqdns': []})
+                mock_log.debug.assert_not_called()
+                mock_log.error.assert_called_once()
+
     def test_core_virtual(self):
         '''
         test virtual grain with cmd virt-what