cli:try:generate: avoid calling 'daemon-reload' through NetworkManager integration during 'netplan try'

Author: slyon

netplan_cli/cli/commands/generate.py

@@ -41,6 +41,7 @@ def run(self):
                                  help='Display the netplan device ID/backend/interface name mapping and exit.')
 
         self.func = self.command_generate
+        self._rootdir = '/'
 
         self.parse_args()
         self.run_command()
@@ -78,12 +79,25 @@ def command_generate(self):
         argv = [utils.get_configure_path()]
         if self.root_dir:
             argv += ['--root-dir', self.root_dir]
+            self._rootdir = self.root_dir
         if self.mapping:
             argv += ['--mapping', self.mapping]
 
+        self._netplan_try_stamp = os.path.join(self._rootdir, self.try_ready_stamp)
         if self.mapping:  # XXX: get rid of the legacy "--mapping" option
             argv[0] = utils.get_generator_path()
             res = subprocess.call(argv)
+        elif os.path.isfile(self._netplan_try_stamp):
+            # Avoid calling the Netplan generator if 'netplan try' is restoring
+            # a previous configuration. See https://github.com/canonical/netplan/pull/548
+            # This is especially relevant when NetworkManager is calling 'netplan generate'
+            # before loading connection profiles, as this would trigger a 'systemctl daemon-reload'
+            # and remove the /run/systemd/generator[.late]/ directories while the sd-generator
+            # itself would be blocked from re-generating the files due to the
+            # /run/netplan/netplan-try.ready stamp.
+            logging.debug('Skipping daemon-reload... \'netplan try\' is restoring configuration, '
+                          'remove %s to force re-run.', self._netplan_try_stamp)
+            res = 1
         else:
             logging.debug('executing Netplan systemd-generator via daemon-reload')
             if self.root_dir:  # for testing purposes

netplan_cli/cli/commands/try_command.py

@@ -50,7 +50,7 @@ def __init__(self):
         self.t_settings = None
         self.t = None
         self._rootdir = os.environ.get('DBUS_TEST_NETPLAN_ROOT', '/')
-        self._netplan_try_stamp = os.path.join(self._rootdir, 'run', 'netplan', 'netplan-try.ready')
+        self._netplan_try_stamp = os.path.join(self._rootdir, self.try_ready_stamp)
 
     @property
     def config_manager(self):  # pragma: nocover (called by later commands)

netplan_cli/cli/utils.py

@@ -297,6 +297,7 @@ def __init__(self, command_id, description, leaf=True, testing=False):
         self.subcommands = {}
         self.subcommand = None
         self.func = None
+        self.try_ready_stamp = 'run/netplan/netplan-try.ready'
         self.generator_dir = '/run/systemd/generator/'
         self.generator_early_dir = '/run/systemd/generator.early/'
         self.generator_late_dir = '/run/systemd/generator.late/'

tests/cli_legacy.py

@@ -183,6 +183,29 @@ def test_mapping_for_renamed_iface(self):
         self.assertNotEqual(b'', out)
         self.assertIn('renamediface', out.decode('utf-8'))
 
+    def test_netplan_try_ready_stamp_skip(self):
+        os.environ.setdefault('NETPLAN_GENERATE_PATH', os.path.join(rootdir, 'generate'))
+        os.environ.setdefault('NETPLAN_CONFIGURE_PATH', os.path.join(rootdir, 'configure'))
+        c = os.path.join(self.workdir.name, 'etc', 'netplan')
+        os.makedirs(c)
+        path_a = os.path.join(c, 'a.yaml')
+        with open(path_a, 'w') as f:
+            f.write('''network:
+  version: 2
+  ethernets:
+    myif:
+      dhcp4: yes
+''')
+        os.chmod(path_a, mode=0o600)
+
+        stamp_file = os.path.join(self.workdir.name, 'run', 'netplan', 'netplan-try.ready')
+        os.makedirs(self.workdir.name + '/run/netplan', mode=0o700, exist_ok=True)
+        open(stamp_file, 'w').close()  # create stamp file
+        res = subprocess.run(exe_cli + ['--debug', 'generate', '--root-dir', self.workdir.name],
+                             text=True, stderr=subprocess.PIPE)
+        self.assertEqual(res.returncode, 1)
+        self.assertIn('DEBUG:Skipping daemon-reload... \'netplan try\' is restoring configuration', res.stderr)
+
 
 class TestIfupdownMigrate(unittest.TestCase):