Compose an RDS managed resource and expose it via a Crossplane claim

Steps

1. Install the AWS provider for Crossplane and configure a ProviderConfig with credentials; the RDS managed resource kind is typically RDSInstance or DBInstance depending on the provider family version—check the provider CRDs.
2. Create a CompositeResourceDefinition (XRD) that defines the custom API type (e.g., XDatabase) with the claim names and schema for inputs such as engine, instanceClass, and storageGB.
3. Write a Composition referencing the XRD that uses a function pipeline (or classic P&T patches) to map XR fields to the RDS managed resource spec fields such as spec.forProvider.dbInstanceClass.
4. Configure writeConnectionSecretToRef in the managed resource spec to store the generated endpoint, username, and password in a Kubernetes Secret; propagate the connection secret to the claim level via connectionDetails in the Composition.
5. Create a namespaced Claim resource (the kind defined in XRD's claimNames) in an application namespace; Crossplane creates the composite resource and the RDS instance automatically.
6. Wait for the managed resource status.conditions to include type: Ready with status: True before consuming the connection secret in application Deployments.