Update makefile rule generate to create temp backend override (#4265)

* Update makefile rule generate to create temp backend override

* Revert "Update makefile rule generate to create temp backend override"

This reverts commit d50cc31.

* Add generate backend override file and update make rule

* Update unit test

* Not make it a tf file when creating the override file

samcli/hook_packages/terraform/hooks/prepare/hook.py

@@ -15,6 +15,7 @@
 import hashlib
 import logging
 import shutil
+import uuid
 
 from samcli.lib.hook.exceptions import PrepareHookException, InvalidSamMetadataPropertiesException
 from samcli.lib.utils import osutils
@@ -46,6 +47,7 @@
 PropertyBuilderMapping = Dict[str, PropertyBuilder]
 
 TERRAFORM_BUILD_SCRIPT = "copy_terraform_built_artifacts.py"
+TF_BACKEND_OVERRIDE_FILENAME = "z_samcli_backend_override"
 
 CFN_CODE_PROPERTIES = {
     CFN_AWS_LAMBDA_FUNCTION: "Code",
@@ -802,6 +804,9 @@ def _generate_makefile(
     if not os.path.exists(output_directory_path):
         os.makedirs(output_directory_path, exist_ok=True)
 
+    # create z_samcli_backend_override.tf in output directory
+    _generate_backend_override_file(output_directory_path)
+
     # copy copy_terraform_built_artifacts.py script into output directory
     copy_terraform_built_artifacts_script_path = os.path.join(
         Path(os.path.dirname(__file__)).parent.parent, TERRAFORM_BUILD_SCRIPT
@@ -814,6 +819,22 @@ def _generate_makefile(
         makefile.writelines(makefile_rules)
 
 
+def _generate_backend_override_file(output_directory_path: str):
+    """
+    Generates an override tf file to use a temporary backend
+
+    Parameters
+    ----------
+    output_directory_path: str
+        the output directory path to write the generated makefile
+    """
+    statefile_filename = f"{uuid.uuid4()}.tfstate"
+    override_content = "terraform {\n" '  backend "local" {\n' f'    path = "./{statefile_filename}"\n' "  }\n" "}\n"
+    override_file_path = os.path.join(output_directory_path, TF_BACKEND_OVERRIDE_FILENAME)
+    with open(override_file_path, "w+") as f:
+        f.write(override_content)
+
+
 def _get_relevant_cfn_resource(
     sam_metadata_resource: SamMetadataResource, cfn_resources: Dict[str, Dict]
 ) -> Tuple[Dict, str]:
@@ -919,14 +940,26 @@ def _generate_makefile_rule_for_lambda_resource(
     """
     target = _get_makefile_build_target(logical_id)
     resource_address = sam_metadata_resource.resource.get("address", "")
+    move_override_recipe = _format_makefile_recipe(
+        "cp "
+        f"{Path(output_dir, TF_BACKEND_OVERRIDE_FILENAME).relative_to(terraform_application_dir)} "
+        f"./{TF_BACKEND_OVERRIDE_FILENAME}.tf"
+    )
+    init_command_recipe = _format_makefile_recipe("terraform init -reconfigure")
     apply_command_template = "terraform apply -target {resource_address} -replace {resource_address} -auto-approve"
     apply_command_recipe = _format_makefile_recipe(apply_command_template.format(resource_address=resource_address))
     show_command_recipe = _format_makefile_recipe(
         _build_show_command(
             python_command_name, output_dir, resource_address, sam_metadata_resource, terraform_application_dir
         )
     )
-    return f"{target}{apply_command_recipe}{show_command_recipe}"
+    return (
+        f"{target}"
+        f"{move_override_recipe}"
+        f"{init_command_recipe}"
+        f"{apply_command_recipe}"
+        f"{show_command_recipe}"
+    )
 
 
 def _build_show_command(

tests/unit/hook_packages/terraform/hooks/prepare/test_hook.py

@@ -2499,10 +2499,15 @@ def test_generate_makefile(
     ):
         mock_os.path.exists.return_value = output_dir_exists
 
+        mock_copy_tf_backend_override_file_path = Mock()
         mock_copy_terraform_built_artifacts_script_path = Mock()
         mock_makefile_path = Mock()
         mock_os.path.dirname.return_value = ""
-        mock_os.path.join.side_effect = [mock_copy_terraform_built_artifacts_script_path, mock_makefile_path]
+        mock_os.path.join.side_effect = [
+            mock_copy_tf_backend_override_file_path,
+            mock_copy_terraform_built_artifacts_script_path,
+            mock_makefile_path,
+        ]
 
         mock_makefile = Mock()
         mock_open.return_value.__enter__.return_value = mock_makefile
@@ -2605,6 +2610,8 @@ def test_get_python_command_name_python_not_found(self, mock_run_side_effect, mo
     @patch("samcli.hook_packages.terraform.hooks.prepare.hook._format_makefile_recipe")
     def test_generate_makefile_rule_for_lambda_resource(self, format_recipe_mock, get_build_target_mock):
         format_recipe_mock.side_effect = [
+            "\tcp .aws-sam-iacs/iacs_metadata/z_samcli_backend_override.tf ./z_samcli_backend_override.tf\n",
+            "\tterraform init -reconfigure\n",
             "\tterraform apply -target null_resource.sam_metadata_aws_lambda_function -auto-approve\n",
             "\tterraform show -json | python3 .aws-sam/iacs_metadata/copy_terraform_built_artifacts.py --expression "
             '"|values|root_module|resources|[?address=="null_resource.sam_metadata_aws_lambda_function"]'
@@ -2624,6 +2631,8 @@ def test_generate_makefile_rule_for_lambda_resource(self, format_recipe_mock, ge
         )
         expected_makefile_rule = (
             "build-function_logical_id:\n"
+            "\tcp .aws-sam-iacs/iacs_metadata/z_samcli_backend_override.tf ./z_samcli_backend_override.tf\n"
+            "\tterraform init -reconfigure\n"
             "\tterraform apply -target null_resource.sam_metadata_aws_lambda_function -auto-approve\n"
             "\tterraform show -json | python3 .aws-sam/iacs_metadata/copy_terraform_built_artifacts.py "
             '--expression "|values|root_module|resources|[?address=="null_resource.sam_metadata_aws_lambda_function"]'