Daemon should remove stale published_hostname file and log useful war…

…ning (#3016)

* Daemon should remove published_hostname file and log useful warning

* Clean up fast track file if vm id has changed

* Clean up initial_goal_state file if vm id has changed

* Clean up rsm_update file if vm id has changed

azurelinuxagent/pa/deprovision/default.py

@@ -158,7 +158,11 @@ def del_lib_dir_files(self, warnings, actions):  # pylint: disable=W0613
             'partition',
             'Protocol',
             'SharedConfig.xml',
-            'WireServerEndpoint'
+            'WireServerEndpoint',
+            'published_hostname',
+            'fast_track.json',
+            'initial_goal_state',
+            'rsm_update.json'
         ]
         known_files_glob = [
             'Extensions.*.xml',

azurelinuxagent/pa/provision/default.py

@@ -172,9 +172,11 @@ def check_provisioned_file(self):
         s = fileutil.read_file(ProvisionHandler.provisioned_file_path()).strip()
         if not self.osutil.is_current_instance_id(s):
             if len(s) > 0:
-                logger.warn("VM is provisioned, "
-                            "but the VM unique identifier has changed -- "
-                            "clearing cached state")
+                msg = "VM is provisioned, but the VM unique identifier has changed. This indicates the VM may be " \
+                      "created from an image that was not properly deprovisioned or generalized, which can result in " \
+                      "unexpected behavior from the guest agent -- clearing cached state"
+                logger.warn(msg)
+                self.report_event(msg)
                 from azurelinuxagent.pa.deprovision \
                     import get_deprovision_handler
                 deprovision_handler = get_deprovision_handler()