app-database-postgresql.yaml

apiVersion: apiextensions.crossplane.io/v1
kind: Composition
metadata:
  name: sql.db.aws.salaboy.com
  labels:
    type: dev
    provider: aws
    kind: sql
spec:
  writeConnectionSecretsToNamespace: crossplane-system
  compositeTypeRef:
    apiVersion: salaboy.com/v1alpha1
    kind: Database
  resources:  
    - name: rdsinstance
      base:
        apiVersion: database.aws.crossplane.io/v1beta1
        kind: RDSInstance
        metadata:
          annotations:
            crossplane.io/external-name: # patched
        spec:
          providerConfigRef:
            name: default
          forProvider:
            region: us-west-2
            allocatedStorage: 5
            dbInstanceClass: db.t3.micro
            engine: postgres
            engineVersion: "13"
            masterUsername: salaboy
            port: 5432
          writeConnectionSecretToRef:
            namespace: crossplane-system
            name: postgresql
      patches:
        - fromFieldPath: metadata.name
          toFieldPath: metadata.annotations[crossplane.io/external-name]
          policy:
            fromFieldPath: Required
        - fromFieldPath: metadata.name
          toFieldPath: metadata.name
          transforms:
            - type: string
              string:
                fmt: "%s-postgres"
      connectionDetails:
        - fromConnectionSecretKey: username
        - fromConnectionSecretKey: password
        - fromConnectionSecretKey: endpoint
        - fromConnectionSecretKey: port