fix: retry setting the computer title

.gitignore

@@ -34,3 +34,5 @@ landscape-client_ppc64el*.txt
 landscape-client_s390x*.txt
 landscape_client.egg-info
 .pybuild
+venv
+.venv

landscape/client/deployment.py

@@ -2,8 +2,10 @@
 import os.path
 import subprocess
 import sys
+import time
 from datetime import datetime
 from datetime import timezone
+from logging import debug
 from optparse import SUPPRESS_HELP
 
 from twisted.logger import globalLogBeginner
@@ -198,7 +200,7 @@ def juju_filename(self):
         backwards-compatibility."""
         return os.path.join(self.data_path, "juju-info.json")
 
-    def auto_configure(self):
+    def auto_configure(self, retry=False, delay=120, max_retries=5):
         """Automatically configure the client snap."""
         client_conf = snap_http.get_conf("landscape-client").result
         auto_enroll_conf = client_conf.get("auto-register", {})
@@ -208,14 +210,24 @@ def auto_configure(self):
         if not enabled or configured:
             return
 
-        title = generate_computer_title(auto_enroll_conf)
-        if title:
-            self.computer_title = title
-            self.write()
+        for _ in range(max_retries):
+            title = generate_computer_title(auto_enroll_conf)
+            if title:
+                self.computer_title = title
+                self.write()
 
-            auto_enroll_conf["configured"] = True
-            client_conf["auto-register"] = auto_enroll_conf
-            snap_http.set_conf("landscape-client", client_conf)
+                auto_enroll_conf["configured"] = True
+                client_conf["auto-register"] = auto_enroll_conf
+                snap_http.set_conf("landscape-client", client_conf)
+                break
+
+            if not retry:
+                break
+
+            # retry until we get the computer title (exponential backoff)
+            # number of retries capped by `max_retries`
+            time.sleep(delay)
+            delay *= 2
 
 
 def get_versioned_persist(service):
@@ -243,11 +255,13 @@ def generate_computer_title(auto_enroll_config):
     snap_info = get_snap_info()
     wait_for_serial = auto_enroll_config.get("wait-for-serial-as", True)
     if "serial" not in snap_info and wait_for_serial:
+        debug(f"No serial assertion in snap info {snap_info}, waiting...")
         return
 
     hostname = get_fqdn()
     wait_for_hostname = auto_enroll_config.get("wait-for-hostname", False)
     if hostname == "localhost" and wait_for_hostname:
+        debug("Waiting for hostname...")
         return
 
     nics = get_active_device_info(default_only=True)

landscape/client/tests/test_deployment.py

@@ -354,6 +354,29 @@ def test_auto_configuration_no_title_generated(
         self.assertIsNone(self.config.get("computer_title"))
         mock_snap_http.set_conf.assert_not_called()
 
+    @mock.patch("landscape.client.deployment.generate_computer_title")
+    @mock.patch("landscape.client.deployment.snap_http")
+    def test_auto_configuration_no_title_generated_retry(
+        self,
+        mock_snap_http,
+        mock_generate_title,
+    ):
+        """The client is not configured."""
+        mock_snap_http.get_conf.return_value = SnapdResponse(
+            "sync",
+            200,
+            "OK",
+            {"auto-register": {"enabled": True, "configured": False}},
+        )
+        mock_generate_title.return_value = None
+
+        self.assertIsNone(self.config.get("computer_title"))
+
+        self.config.auto_configure(retry=True, delay=0.01, max_retries=2)
+        assert mock_generate_title.call_count == 2
+        self.assertIsNone(self.config.get("computer_title"))
+        mock_snap_http.set_conf.assert_not_called()
+
 
 class GetVersionedPersistTest(LandscapeTest):
     def test_upgrade_service(self):
@@ -424,10 +447,12 @@ def test_generate_computer_title(
         )
         self.assertEqual(title, "classic-f315cab5")
 
+    @mock.patch("landscape.client.deployment.debug")
     @mock.patch("landscape.client.deployment.get_snap_info")
     def test_generate_computer_title_wait_for_serial_no_serial_assertion(
         self,
         mock_snap_info,
+        mock_debug,
     ):
         """Returns `None`."""
         mock_snap_info.return_value = {}
@@ -442,13 +467,18 @@ def test_generate_computer_title_wait_for_serial_no_serial_assertion(
             },
         )
         self.assertIsNone(title)
+        mock_debug.assert_called_once_with(
+            "No serial assertion in snap info {}, waiting..."
+        )
 
+    @mock.patch("landscape.client.deployment.debug")
     @mock.patch("landscape.client.deployment.get_fqdn")
     @mock.patch("landscape.client.deployment.get_snap_info")
     def test_generate_computer_title_wait_for_hostname(
         self,
         mock_snap_info,
         mock_fqdn,
+        mock_debug,
     ):
         """Returns `None`."""
         mock_snap_info.return_value = {
@@ -468,6 +498,7 @@ def test_generate_computer_title_wait_for_hostname(
             },
         )
         self.assertIsNone(title)
+        mock_debug.assert_called_once_with("Waiting for hostname...")
 
     @mock.patch("landscape.client.deployment.subprocess")
     @mock.patch("landscape.client.deployment.get_active_device_info")

landscape/client/tests/test_watchdog.py

@@ -1527,5 +1527,5 @@ def test_is_snap(self, mock_auto_configure):
         with mock.patch("landscape.client.watchdog.pwd", new=self.fake_pwd):
             run(["--log-dir", self.makeDir()], reactor=reactor)
 
-        mock_auto_configure.assert_called_once_with()
+        mock_auto_configure.assert_called_once_with(retry=True)
         self.assertTrue(reactor.running)

landscape/client/watchdog.py

@@ -721,7 +721,7 @@ def run(args=sys.argv, reactor=None):
     init_logging(config, "watchdog")
 
     if IS_SNAP:
-        config.auto_configure()
+        config.auto_configure(retry=True)
 
     application = Application("landscape-client")
     watchdog_service = WatchDogService(config)