test(vm_extensions): add CustomScript boot validation test case

lisa/microsoft/testsuites/vm_extensions/runtime_extensions/custom_script.py

@@ -103,6 +103,52 @@ def before_case(self, log: Logger, **kwargs: Any) -> None:
         node: Node = kwargs.pop("node")
         check_waagent_version_supported(node=node)
 
+    @TestCaseMetadata(
+        description="""
+        Basic boot validation for the Custom Script VM extension.
+
+        Installs the extension with a single inline commandToExecute and no file
+        uris, so it needs no storage account or public blob access. Verifies that
+        provisioning succeeds, then removes the extension.
+
+        The extension publisher, type and version are read from runbook variables
+        (extension_publisher, extension_type, extension_version), defaulting to the
+        Custom Script extension. The deployed extension is named
+        '<publisher>_<extension_type>_boot_validation_test'.
+        """,
+        priority=1,
+    )
+    def microsoft_azure_extensions_customscript_boot_validation_test(
+        self, log: Logger, node: Node, variables: Dict[str, Any]
+    ) -> None:
+        publisher: str = variables.get(
+            "extension_publisher", "Microsoft.Azure.Extensions"
+        ).strip()
+        extension_type: str = variables.get("extension_type", "CustomScript").strip()
+        version: str = variables.get("extension_version", "2.1").strip()
+
+        extension_name = f"{publisher}_{extension_type}_boot_validation_test"
+        settings = {"commandToExecute": "echo 'CSE test success'"}
+
+        extension = node.features[AzureExtension]
+        extension.delete(name=extension_name, ignore_not_found=True)
+
+        log.info(f"Installing extension '{extension_name}'...")
+        result = extension.create_or_update(
+            name=extension_name,
+            publisher=publisher,
+            type_=extension_type,
+            type_handler_version=version,
+            auto_upgrade_minor_version=True,
+            settings=settings,
+        )
+
+        assert_that(result["provisioning_state"]).described_as(
+            "Expected the extension to succeed"
+        ).is_equal_to("Succeeded")
+
+        extension.delete(name=extension_name, ignore_not_found=True)
+
     @TestCaseMetadata(
         description="""
         Runs the Custom Script VM extension with a public Azure storage file uri.