Fix bug with dependent extensions with no settings (#2285) (#2349)

Co-authored-by: Laveesh Rohra <larohra@microsoft.com>

azurelinuxagent/ga/exthandlers.py

@@ -563,9 +563,13 @@ def wait_for_handler_completion(handler_i, wait_until, extension=None):
         Check the status of the extension being handled. Wait until it has a terminal state or times out.
         :raises: Exception if it is not handled successfully.
         """
-
         extension_name = handler_i.get_extension_full_name(extension)
 
+        # If the handler had no settings, we should not wait at all for handler to report status.
+        if extension is None:
+            logger.info("No settings found for {0}, not waiting for it's status".format(extension_name))
+            return
+
         try:
             ext_completed, status = False, None
 
@@ -1652,7 +1656,9 @@ def get_status_file_path(self, extension=None):
     def collect_ext_status(self, ext):
         self.logger.verbose("Collect extension status for {0}".format(self.get_extension_full_name(ext)))
         seq_no, ext_status_file = self.get_status_file_path(ext)
-        if seq_no == -1:
+
+        # We should never try to read any status file if the handler has no settings, returning None in that case
+        if seq_no == -1 or ext is None:
             return None
 
         data = None

tests/data/wire/ext_conf_dependencies_with_empty_settings.xml

@@ -0,0 +1,32 @@
+<Extensions version="1.0.0.0" goalStateIncarnation="9">
+    <GuestAgentExtension
+            xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
+        <GAFamilies>
+            <GAFamily>
+                <Name>Prod</Name>
+                <Uris>
+                    <Uri>http://mock-goal-state/manifest_of_ga.xml</Uri>
+                </Uris>
+            </GAFamily>
+            <GAFamily>
+                <Name>Test</Name>
+                <Uris>
+                    <Uri>http://mock-goal-state/manifest_of_ga.xml</Uri>
+                </Uris>
+            </GAFamily>
+        </GAFamilies>
+    </GuestAgentExtension>
+    <Plugins>
+        <Plugin name="OSTCExtensions.ExampleHandlerLinux" version="1.0.0" location="http://mock-goal-state/rdfepirv2hknprdstr03.blob.core.windows.net/b01058962be54ceca550a390fa5ff064/Microsoft.OSTCExtensions_ExampleHandlerLinux_asiaeast_manifest.xml" config="" state="enabled" autoUpgrade="false" failoverlocation="http://mock-goal-state/rdfepirv2hknprdstr04.blob.core.windows.net/b01058962be54ceca550a390fa5ff064/Microsoft.OSTCExtensions_ExampleHandlerLinux_asiaeast_manifest.xml" runAsStartupTask="false" isJson="true" />
+        <Plugin name="OSTCExtensions.OtherExampleHandlerLinux" version="1.0.0" location="http://mock-goal-state/rdfepirv2hknprdstr03.blob.core.windows.net/b01058962be54ceca550a390fa5ff064/Microsoft.OSTCExtensions_OtherExampleHandlerLinux_asiaeast_manifest.xml" config="" state="enabled" autoUpgrade="false" failoverlocation="http://mock-goal-state/rdfepirv2hknprdstr04.blob.core.windows.net/b01058962be54ceca550a390fa5ff064/Microsoft.OSTCExtensions_OtherExampleHandlerLinux_asiaeast_manifest.xml" runAsStartupTask="false" isJson="true" />
+    </Plugins>
+    <PluginSettings>
+        <Plugin name="OSTCExtensions.ExampleHandlerLinux" version="1.0.0">
+            <DependsOn dependencyLevel="1">
+                <DependsOnExtension handler="OSTCExtensions.OtherExampleHandlerLinux" />
+            </DependsOn>
+            <RuntimeSettings seqNo="0">{"runtimeSettings":[{"handlerSettings":{"protectedSettingsCertThumbprint":"4037FBF5F1F3014F99B5D6C7799E9B20E6871CB3","protectedSettings":"MIICWgYJK","publicSettings":{"foo":"bar"}}}]}</RuntimeSettings>
+        </Plugin>
+    </PluginSettings>
+    <StatusUploadBlob statusBlobType="BlockBlob">https://test.blob.core.windows.net/vhds/test-cs12.test-cs12.test-cs12.status?sr=b&amp;sp=rw&amp;se=9999-01-01&amp;sk=key1&amp;sv=2014-02-14&amp;sig=hfRh7gzUE7sUtYwke78IOlZOrTRCYvkec4hGZ9zZzXo</StatusUploadBlob>
+</Extensions>

tests/ga/test_extension.py

@@ -994,6 +994,38 @@ def test_ext_handler_sequencing(self, *args):
                 (dep_ext_level_5, ExtensionCommandNames.UNINSTALL)
             )
 
+    def test_it_should_process_sequencing_properly_even_if_no_settings_for_dependent_extension(
+            self, mock_get, mock_crypt, *args):
+        test_data_file = DATA_FILE.copy()
+        test_data_file["ext_conf"] = "wire/ext_conf_dependencies_with_empty_settings.xml"
+        test_data = mockwiredata.WireProtocolData(test_data_file)
+        exthandlers_handler, protocol = self._create_mock(test_data, mock_get, mock_crypt, *args)
+
+        ext_1 = extension_emulator(name="OSTCExtensions.ExampleHandlerLinux")
+        ext_2 = extension_emulator(name="OSTCExtensions.OtherExampleHandlerLinux")
+
+        with enable_invocations(ext_1, ext_2) as invocation_record:
+            exthandlers_handler.run()
+            exthandlers_handler.report_ext_handlers_status()
+
+            # Ensure no extension status was reported for OtherExampleHandlerLinux as no settings provided for it
+            self._assert_handler_status(protocol.report_vm_status, "Ready", 0, "1.0.0",
+                                        expected_handler_name="OSTCExtensions.OtherExampleHandlerLinux")
+
+            # Ensure correct status reported back for the other extension with settings
+            self._assert_handler_status(protocol.report_vm_status, "Ready", 1, "1.0.0",
+                                        expected_handler_name="OSTCExtensions.ExampleHandlerLinux")
+            self._assert_ext_status(protocol.report_vm_status, "success", 0,
+                                    expected_handler_name="OSTCExtensions.ExampleHandlerLinux")
+
+            # Ensure the invocation order follows the dependency levels
+            invocation_record.compare(
+                (ext_2, ExtensionCommandNames.INSTALL),
+                (ext_2, ExtensionCommandNames.ENABLE),
+                (ext_1, ExtensionCommandNames.INSTALL),
+                (ext_1, ExtensionCommandNames.ENABLE)
+            )
+
     def test_ext_handler_sequencing_should_fail_if_handler_failed(self, mock_get, mock_crypt, *args):
         test_data = mockwiredata.WireProtocolData(mockwiredata.DATA_FILE_EXT_SEQUENCING)
         exthandlers_handler, protocol = self._create_mock(test_data, mock_get, mock_crypt, *args)