Compose stacks with kro

What's been set up for you

• The kro EKS-managed capability is ACTIVE on the cluster, with the resourcegraphdefinitions.kro.run CRD registered.
• The ACK DynamoDB capability from Lab 1 is still ACTIVE — kro will compose its Table custom resource alongside native Kubernetes objects.
• The pre-provisioned ${EKS_CLUSTER_AUTO_NAME}-carts-dynamo IAM role is wildcard-scoped to ${EKS_CLUSTER_AUTO_NAME}-carts-* tables, so the same role covers Lab 1's -carts-fastpath table and Lab 3's -carts-kro table without changes.

In Lab 1 you applied three separate manifests — a Table custom resource, a ConfigMap override, and a Pod Identity association — to migrate carts onto an AWS-managed DynamoDB table. That's the right altitude for a one-off, but a platform team running this for many services would want one user-facing CR that captures the whole stack.

In this lab you'll do exactly that with the kro EKS capability. kro lets you define a ResourceGraphDefinition (RGD) — a schema for a higher-level CR plus the graph of resources it expands into — and apply a single instance that bundles a Namespace, an ACK Table, a ConfigMap, and a ServiceAccount. The kro controllers run in AWS-owned infrastructure outside the cluster; you only see the CRDs they registered.

Throughout this lab, we will:

1. Verify the kro capability is ACTIVE and the resourcegraphdefinitions.kro.run CRD is present.
2. Apply a CartsStack ResourceGraphDefinition that composes Namespace + ACK Table + ConfigMap + ServiceAccount + Deployment + Service.
3. Apply a CartsStack instance, observe kro reconcile its child resources in order, then bind a Pod Identity association so the carts Pod can read and write the new table.

A single CartsStack apply produces this graph:

                you apply:
                CartsStack/carts-kro          (one CR, two required fields)
                       │
                       ▼  kro reconciler expands the RGD
                       │
   ┌──────────┬────────┴──┬──────────┬─────────────┬──────────┐
   ▼          ▼           ▼          ▼             ▼          ▼
Namespace   Table     ConfigMap     SA        Deployment    Service
                        │                          │
                        ▼                          ▼
                   ACK DynamoDB                 Pod (carts-…)
                    controller                       │
                        │                            │ + aws eks create-pod-identity-association
                        ▼                            ▼
                AWS DynamoDB table          AWS_CONTAINER_CREDENTIALS
                (eks-workshop-…-carts-kro)   via Pod Identity Agent

備考

kro itself does not call AWS APIs — it only reconciles Kubernetes resources. Anything that needs to create an AWS resource flows through a controller that does (in this lab, the ACK DynamoDB controller from Lab 1). Pod Identity is an EKS API rather than a Kubernetes API, so the binding step at the end of this lab is a one-line aws eks command, not part of the RGD.