Fix ModuleNotFoundError for older pinned functions versions

Author: gavin-aguiar

azure_functions_worker/functions.py

@@ -5,7 +5,7 @@
 import pathlib
 import typing
 
-from azure.functions import DataType, Function
+from azure_functions_worker.utils.library_importer import Function
 
 from . import bindings as bindings_utils
 from . import protos
@@ -216,8 +216,7 @@ def validate_function_params(params: dict, bound_params: dict,
                         param_bind_type, param_py_type)
 
                 if not checks_out:
-                    if binding.data_type is not DataType(
-                            protos.BindingInfo.undefined):
+                    if binding.data_type is not protos.BindingInfo.undefined:
                         raise FunctionLoadError(
                             func_name,
                             f'{param.name!r} binding type "{binding.type}" '

azure_functions_worker/loader.py

@@ -12,7 +12,7 @@
 from os import PathLike, fspath
 from typing import List, Optional, Dict
 
-from azure.functions import Function, FunctionApp
+from .utils.library_importer import Function, FunctionApp
 
 from . import protos, functions
 from .constants import MODULE_NOT_FOUND_TS_URL, SCRIPT_FILE_NAME, \

azure_functions_worker/utils/library_importer.py

@@ -0,0 +1,33 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+import logging
+
+"""
+File to import library dependencies.
+This file should be used to import any dependency from the library since
+directly importing azure.functions may cause ModuleNotFound error is the user
+has pinned their azure.functions to an older release version.
+
+"""
+
+
+def get_azure_function():
+    try:
+        from azure.functions import Function as func
+        return func
+    except ImportError:
+        logging.error("azure.functions is pinned to an older version. "
+                      "Please pin azure.functions to version 1.10.1 or higher")
+
+
+def get_azure_function_app():
+    try:
+        from azure.functions import FunctionApp as funcApp
+        return funcApp
+    except ImportError:
+        logging.error("azure.functions is pinned to an older version. "
+                      "Please pin azure.functions to version 1.10.1 or higher")
+
+
+Function = get_azure_function()
+FunctionApp = get_azure_function_app()