update default EKS cluster entity transformer

This change has no functional effect, but it seems like a helpful illustration
for adopters embarking on writing the first EKS cluster entity transformer of
their own.

Signed-off-by: Jamie Klassen <jamie.klassen@broadcom.com>

.changeset/dull-dolphins-explain.md

@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-catalog-backend-module-aws': patch
+---
+
+The default EKS cluster entity transformer now sets the new
+`kubernetes.io/x-k8s-aws-id` annotation.

plugins/catalog-backend-module-aws/src/lib/defaultTransformers.ts

@@ -18,6 +18,7 @@ import {
   ANNOTATION_KUBERNETES_API_SERVER,
   ANNOTATION_KUBERNETES_API_SERVER_CA,
   ANNOTATION_KUBERNETES_AUTH_PROVIDER,
+  ANNOTATION_KUBERNETES_AWS_CLUSTER_ID,
 } from '@backstage/plugin-kubernetes-common';
 import type { EksClusterEntityTransformer } from '../processors/types';
 import { ANNOTATION_AWS_ACCOUNT_ID, ANNOTATION_AWS_ARN } from '../constants';
@@ -29,6 +30,7 @@ import { ANNOTATION_AWS_ACCOUNT_ID, ANNOTATION_AWS_ARN } from '../constants';
 export const defaultEksClusterEntityTransformer: EksClusterEntityTransformer =
   async (cluster: Cluster, accountId: string) => {
     const { arn, endpoint, certificateAuthority, name } = cluster;
+    const normalizedName = normalizeName(name as string);
     return {
       apiVersion: 'backstage.io/v1alpha1',
       kind: 'Resource',
@@ -40,8 +42,9 @@ export const defaultEksClusterEntityTransformer: EksClusterEntityTransformer =
           [ANNOTATION_KUBERNETES_API_SERVER_CA]:
             certificateAuthority?.data || '',
           [ANNOTATION_KUBERNETES_AUTH_PROVIDER]: 'aws',
+          [ANNOTATION_KUBERNETES_AWS_CLUSTER_ID]: normalizedName,
         },
-        name: normalizeName(name as string),
+        name: normalizedName,
         namespace: 'default',
       },
       spec: {

plugins/catalog-backend-module-aws/src/processors/AwsEKSClusterProcessor.test.ts

@@ -67,6 +67,7 @@ describe('AwsEKSClusterProcessor', () => {
               'kubernetes.io/api-server-certificate-authority':
                 cluster.cluster?.certificateAuthority?.data,
               'kubernetes.io/auth-provider': 'aws',
+              'kubernetes.io/x-k8s-aws-id': 'backstage-test',
             },
             name: 'backstage-test',
             namespace: 'default',