Ignore dependencies when the extension does not have any settings (#2957

) (#2962)

* Ignore dependencies when the extension does not have any settings

* Remove message

---------

Co-authored-by: narrieta <narrieta>
(cherry picked from commit 79bc12c)

azurelinuxagent/common/event.py

@@ -109,6 +109,7 @@ class WALAEventOperation:
     OpenSsl = "OpenSsl"
     Partition = "Partition"
     PersistFirewallRules = "PersistFirewallRules"
+    ProvisionAfterExtensions = "ProvisionAfterExtensions"
     PluginSettingsVersionMismatch = "PluginSettingsVersionMismatch"
     InvalidExtensionConfig = "InvalidExtensionConfig"
     Provision = "Provision"

azurelinuxagent/common/protocol/extensions_goal_state_from_vm_settings.py

@@ -22,6 +22,7 @@
 
 from azurelinuxagent.common import logger
 from azurelinuxagent.common.AgentGlobals import AgentGlobals
+from azurelinuxagent.common.event import WALAEventOperation, add_event
 from azurelinuxagent.common.future import ustr
 from azurelinuxagent.common.protocol.extensions_goal_state import ExtensionsGoalState, GoalStateChannel, VmSettingsParseError
 from azurelinuxagent.common.protocol.restapi import VMAgentFamily, Extension, ExtensionRequestedState, ExtensionSettings
@@ -492,11 +493,28 @@ def _parse_dependency_level(depends_on, extension):
             length = len(depends_on)
             if length > 1:
                 raise Exception('dependsOn should be an array with exactly one item for single-config extensions ({0}) (got {1})'.format(extension.name, depends_on))
-            elif length == 0:
+            if length == 0:
                 logger.warn('dependsOn is an empty array for extension {0}; setting the dependency level to 0'.format(extension.name))
-                extension.settings[0].dependencyLevel = 0
+                dependency_level = 0
             else:
-                extension.settings[0].dependencyLevel = depends_on[0]['dependencyLevel']
+                dependency_level = depends_on[0]['dependencyLevel']
+                depends_on_extension = depends_on[0].get('dependsOnExtension')
+                if depends_on_extension is None:
+                    # TODO: Consider removing this check and its telemetry after a few releases if we do not receive any telemetry indicating
+                    #       that dependsOnExtension is actually missing from the vmSettings
+                    message = 'Missing dependsOnExtension on extension {0}'.format(extension.name)
+                    logger.warn(message)
+                    add_event(WALAEventOperation.ProvisionAfterExtensions, message=message, is_success=False, log_event=False)
+                else:
+                    message = '{0} depends on {1}'.format(extension.name, depends_on_extension)
+                    logger.info(message)
+                    add_event(WALAEventOperation.ProvisionAfterExtensions, message=message, is_success=True, log_event=False)
+            if len(extension.settings) == 0:
+                message = 'Extension {0} does not have any settings. Will ignore dependency (dependency level: {1})'.format(extension.name, dependency_level)
+                logger.warn(message)
+                add_event(WALAEventOperation.ProvisionAfterExtensions, message=message, is_success=False, log_event=False)
+            else:
+                extension.settings[0].dependencyLevel = dependency_level
         else:
             # multi-config
             settings_by_name = {}

azurelinuxagent/ga/agent_update_handler.py

@@ -268,9 +268,6 @@ def __check_if_downgrade_is_requested_and_allowed(self, requested_version):
         """
         if not self._is_requested_version_update:
             if requested_version < CURRENT_VERSION:
-                msg = "Downgrade requested in the GoalState, but downgrades are not supported for self-update version:{0}, " \
-                      "skipping agent update".format(requested_version)
-                self.__log_event(LogLevel.INFO, msg)
                 return False
         return True