cli:status fail cleanly if systemd-networkd is not present

This has a clean and clear error message instead of a python stack trace if systemd-networkd is not present on the system.

Author: jonathanspw

netplan_cli/cli/state.py

@@ -433,6 +433,9 @@ def __init__(self, ifname=None, all=False):
                               'but systemd-networkd.service is masked. '
                               'Please start it.')
                 sys.exit(1)
+            if not utils.systemctl_is_installed('systemd-networkd.service'):
+                logging.error('systemd-networkd is required for \'netplan status\' functionality')
+                sys.exit(1)
             logging.debug('systemd-networkd.service is not active. Starting...')
             utils.systemctl('start', ['systemd-networkd.service'], True)
 

tests/cli/test_status.py

@@ -531,6 +531,18 @@ def test_call_cli_networkd_masked(self, is_masked_mock, is_active_mock):
         self.assertEqual(1, e.exception.code)
         self.assertIn('systemd-networkd.service is masked', cm.output[0])
 
+    @patch('netplan_cli.cli.utils.systemctl_is_installed')
+    @patch('netplan_cli.cli.utils.systemctl_is_active')
+    @patch('netplan_cli.cli.utils.systemctl_is_masked')
+    def test_call_cli_networkd_installed_false(self, is_installed_mock, is_active_mock, is_masked_mock):
+        is_active_mock.return_value = False
+        is_masked_mock.return_value = False
+        is_installed_mock.return_value = False
+        with self.assertLogs() as cm, self.assertRaises(SystemExit) as e:
+            self._call([])
+        self.assertEqual(1, e.exception.code)
+        self.assertIn('systemd-networkd is required for \'netplan status\' functionality', cm.output[0])
+
     @patch('netplan_cli.cli.state.NetplanConfigState.__init__')
     @patch('netplan_cli.cli.state_diff.NetplanDiffState.__init__')
     @patch('netplan_cli.cli.state_diff.NetplanDiffState.get_diff')