comp.yaml

apiVersion: apiextensions.crossplane.io/v1
kind: Composition
metadata:
  name: compositepostgresqlinstances.aws.database.example.org
  labels:
    provider: aws
    guide: quickstart
    vpc: default
spec:
  writeConnectionSecretsToNamespace: crossplane-system
  compositeTypeRef:
    apiVersion: database.example.org/v1alpha1
    kind: CompositePostgreSQLInstance
  resources:
    - name: rdsinstance
      base:
        apiVersion: database.aws.crossplane.io/v1beta1
        kind: RDSInstance
        spec:
          forProvider:
            region: us-east-1
            dbInstanceClass: db.t2.small
            masterUsername: masteruser
            engine: postgres
            engineVersion: "9.6"
            skipFinalSnapshotBeforeDeletion: true
            publiclyAccessible: true
          writeConnectionSecretToRef:
            namespace: crossplane-system
      patches:
        - type: CombineFromCompositeFieldPaths
          combineFrom:
            variables:
            - fieldPath: "metadata.name"
            - fieldPath: "spec.somefield"
            strategy: string # maybe "template" in future?
            string:
              fmt: "%s-somestuff-%s"
          toFieldPath: "spec.policy"
          transforms:
          - type: string
            string:
              fmt: "%s-value"
        # The direction? Could it ever be ToComposite?
        # Maybe we can inject random generator?
        # Why "From" prefix? "ConstantValue"?
        - type: FromConstantValue
          constantValue:
            type: int
            int: 55
          toFieldPath: "spec.number"
        # Type has always been about direction AND (if fromMany accepted) form of the input.
        # It's a bit of a departure, similar to PatchSet. We're getting closer to "type can be anything".
        # Maybe use "FromConstantValue" that has random string set and then have "randomString" transform accept it as input set?
        # Though we need to consider whether future Fns could be worth the addition.
        # Once set and don't touch? Is this compatible with current composition mechanics?
        - type: FromFn
          fromFn:
            type: randomString
            randomString: "abcdefdgsdgds"
          toFieldPath: "spec.randomId"
        - fromFieldPath: "metadata.uid"
          toFieldPath: "spec.writeConnectionSecretToRef.name"
          transforms:
            - type: string
              string:
                fmt: "%s-postgresql"
        - fromFieldPath: "spec.parameters.storageGB"
          toFieldPath: "spec.forProvider.allocatedStorage"
      connectionDetails:
        - fromConnectionSecretKey: username
        - fromConnectionSecretKey: password
        - fromConnectionSecretKey: endpoint
        - fromConnectionSecretKey: port