From 590f0c075c87555c3e0e4664fbcb8bb54e110dc6 Mon Sep 17 00:00:00 2001
From: Adam Moussa <166072409+amoussa1229@users.noreply.github.com>
Date: Wed, 15 Jul 2026 15:54:14 -0400
Subject: [PATCH] fix(infra): grant KB role rds:DescribeDBClusters (prod deploy
 blocker) (#229)

The seahaven-prod deploy failed at CreateKnowledgeBase: the Bedrock KB execution
role (proposal-system-kb-role) was denied rds:DescribeDBClusters, which Bedrock
calls to validate the Aurora pgvector store config. Add it. rds:DescribeDBClusters
does NOT support resource-level scoping (account/region list action) so it must be
Resource:*; the role's sensitive actions (rds-data:*, s3, InvokeModel, secret) stay
tightly scoped. GPT-4.1 cross-review APPROVE (caught the Resource:* requirement).
---
 infra/lib/compute-stack.ts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/infra/lib/compute-stack.ts b/infra/lib/compute-stack.ts
index 95b88b0..867d38c 100644
--- a/infra/lib/compute-stack.ts
+++ b/infra/lib/compute-stack.ts
@@ -86,6 +86,17 @@ export class ComputeStack extends cdk.Stack {
       resources: [`arn:aws:bedrock:us-east-1::foundation-model/amazon.titan-embed-text-v2:0`],
     }));
 
+    // Bedrock validates the Aurora vector-store config at KB-create time by calling
+    // rds:DescribeDBClusters — required or CreateKnowledgeBase 400s with "storage
+    // configuration provided is invalid" / rds:DescribeDBClusters AccessDenied.
+    // NOTE: rds:DescribeDBClusters does NOT support resource-level permissions (it is an
+    // account/region list action), so it must be Resource:* — scoping to the cluster ARN
+    // grants nothing. Read-only metadata; the role's sensitive actions stay scoped.
+    kbRole.addToPolicy(new iam.PolicyStatement({
+      actions: ['rds:DescribeDBClusters'],
+      resources: ['*'],
+    }));
+
     // KB queries the pgvector table via the RDS Data API as bedrock_user.
     kbRole.addToPolicy(new iam.PolicyStatement({
       actions: [