fix(rds): add the dependency on proxy targets to ensure dbInstance (#…

…12237)

availability while creating the proxy

Fixes: #11311


----

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

packages/@aws-cdk/aws-rds/lib/proxy.ts

@@ -447,13 +447,15 @@ export class DatabaseProxy extends DatabaseProxyBase
       throw new Error('Cannot specify both dbInstanceIdentifiers and dbClusterIdentifiers');
     }
 
-    new CfnDBProxyTargetGroup(this, 'ProxyTargetGroup', {
+    const proxyTargetGroup = new CfnDBProxyTargetGroup(this, 'ProxyTargetGroup', {
       targetGroupName: 'default',
       dbProxyName: this.dbProxyName,
       dbInstanceIdentifiers,
       dbClusterIdentifiers,
       connectionPoolConfigurationInfo: toConnectionPoolConfigurationInfo(props),
     });
+
+    bindResult.dbClusters?.forEach((c) => proxyTargetGroup.node.addDependency(c));
   }
 
   /**

packages/@aws-cdk/aws-rds/test/test.proxy.ts

@@ -1,4 +1,4 @@
-import { ABSENT, expect, haveResourceLike } from '@aws-cdk/assert';
+import { ABSENT, expect, haveResourceLike, ResourcePart } from '@aws-cdk/assert';
 import * as ec2 from '@aws-cdk/aws-ec2';
 import { AccountPrincipal, Role } from '@aws-cdk/aws-iam';
 import * as secretsmanager from '@aws-cdk/aws-secretsmanager';
@@ -263,4 +263,42 @@ export = {
 
     test.done();
   },
+
+  'DBProxyTargetGroup should have dependency on the proxy targets'(test: Test) {
+    // GIVEN
+    const cluster = new rds.DatabaseCluster(stack, 'cluster', {
+      engine: rds.DatabaseClusterEngine.AURORA,
+      instanceProps: {
+        vpc,
+      },
+    });
+
+    //WHEN
+    new rds.DatabaseProxy(stack, 'proxy', {
+      proxyTarget: rds.ProxyTarget.fromCluster(cluster),
+      secrets: [cluster.secret!],
+      vpc,
+    });
+
+    // THEN
+    expect(stack).to(haveResourceLike('AWS::RDS::DBProxyTargetGroup', {
+      Properties: {
+        DBProxyName: {
+          Ref: 'proxy3A1DA9C7',
+        },
+        TargetGroupName: 'default',
+      },
+      DependsOn: [
+        'clusterInstance183584D40',
+        'clusterInstance23D1AD8B2',
+        'cluster611F8AFF',
+        'clusterSecretAttachment69BFCEC4',
+        'clusterSecretE349B730',
+        'clusterSecurityGroupF441DCEA',
+        'clusterSubnets81E3593F',
+      ],
+    }, ResourcePart.CompleteDefinition));
+
+    test.done();
+  },
 };