Make Topic Name an immutable field (#65)

Issue [#2196](aws-controllers-k8s/community#2196)

Description of changes:
* Make topic name immutable
* Add e2e test checking for error after topic name change

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

apis/v1alpha1/ack-generate-metadata.yaml

@@ -1,13 +1,13 @@
 ack_generate_info:
-  build_date: "2024-10-24T02:09:19Z"
-  build_hash: 36c2d234498c2bc4f60773ab8df632af4067f43b
+  build_date: "2024-10-25T16:48:58Z"
+  build_hash: ab15f9206796e9660c51695fab0ff07a09ea28e2
   go_version: go1.23.2
-  version: v0.39.1
+  version: v0.39.1-2-gab15f92
 api_directory_checksum: 07a2ec03f194442b69cf147a88a4cc33badaa895
 api_version: v1alpha1
 aws_sdk_go_version: v1.49.0
 generator_config_info:
-  file_checksum: e95b5fd9a0571826102c9546eae4cc73228a8395
+  file_checksum: da7d9b038cf0421583a14109fe0e04628911ab69
   original_file_name: generator.yaml
 last_modification:
   reason: API generation

apis/v1alpha1/generator.yaml

@@ -62,6 +62,8 @@ resources:
       sdk_get_attributes_post_set_output:
         template_path: hooks/topic/sdk_get_attributes_post_set_output.go.tpl
     fields:
+      Name:
+        is_immutable: true
       TopicArn:
         is_attribute: true
         is_arn: true

generator.yaml

@@ -62,6 +62,8 @@ resources:
       sdk_get_attributes_post_set_output:
         template_path: hooks/topic/sdk_get_attributes_post_set_output.go.tpl
     fields:
+      Name:
+        is_immutable: true
       TopicArn:
         is_attribute: true
         is_arn: true

pkg/resource/topic/hooks.go

@@ -16,6 +16,7 @@ package topic
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	ackv1alpha1 "github.com/aws-controllers-k8s/runtime/apis/core/v1alpha1"
 	ackcompare "github.com/aws-controllers-k8s/runtime/pkg/compare"
@@ -60,6 +61,10 @@ func (rm *resourceManager) customUpdate(
 	defer func() {
 		exit(err)
 	}()
+	if immutableFieldChanges := rm.getImmutableFieldChanges(delta); len(immutableFieldChanges) > 0 {
+		msg := fmt.Sprintf("Immutable Spec fields have been modified: %s", strings.Join(immutableFieldChanges, ","))
+		return nil, ackerr.NewTerminalError(fmt.Errorf(msg))
+	}
 	if delta.DifferentAt("Spec.Tags") {
 		if err := rm.syncTags(ctx, desired, latest); err != nil {
 			return nil, err

templates/hooks/topic/sdk_get_attributes_pre_set_output.go.tpl

@@ -1,13 +1,11 @@
 
-	// If the Name field is empty, populate it with the last part of the topic ARN
+	// Populate the name field with the last part of the topic ARN
 	// This is a workaround for the fact that the Name field is required by the
 	// CreateTopic API call, but not by the GetTopicAttributes API call
 	// Use case: adopting an existing topic by topic ARN
-	if ko.Spec.Name == nil {
-		topicName, err := rm.getTopicNameFromARN(tmpARN)
-		if err != nil {
-			return nil, err
-		}
-		ko.Spec.Name = &topicName
+	topicName, err := rm.getTopicNameFromARN(tmpARN)
+	if err != nil {
+		return nil, err
 	}
+	ko.Spec.Name = &topicName
 

test/e2e/tests/test_topic.py

@@ -177,6 +177,19 @@ def test_crud(self, simple_topic):
             expect_after_update_tags, latest_tags,
         )
 
+        updates = {
+            "spec": {"name": "my-simple-topic-edited"}
+        }
+        k8s.patch_custom_resource(ref, updates)
+        time.sleep(MODIFY_WAIT_AFTER_SECONDS)
+        k8s.wait_resource_consumed_by_controller(ref)
+        condition.assert_type_status(ref, condition.CONDITION_TYPE_TERMINAL) 
+
+        expected_msg = "Immutable Spec fields have been modified: Name"
+        terminal_condition = k8s.get_resource_condition(ref, condition.CONDITION_TYPE_TERMINAL)
+        # The name is immutable, testing if we get a terminal error
+        assert expected_msg in terminal_condition['message']
+
     def test_crud_fifo(self, fifo_topic):
         ref, res = fifo_topic