Add reference for Configuration to kafka cluster

apis/kafka/v1beta1/reference.go

@@ -0,0 +1,24 @@
+package v1beta1
+
+import (
+	"github.com/crossplane/crossplane-runtime/pkg/fieldpath"
+	"github.com/crossplane/crossplane-runtime/pkg/reference"
+	xpresource "github.com/crossplane/crossplane-runtime/pkg/resource"
+)
+
+// Lovingly ripped off from config/common/ARNExtractor. Is there a better way?
+func GetConfigurationRevision() reference.ExtractValueFn {
+	return func(mg xpresource.Managed) string {
+		paved, err := fieldpath.PaveObject(mg)
+		if err != nil {
+			// todo(hasan): should we log this error?
+			return ""
+		}
+		r, err := paved.GetString("status.atProvider.revision")
+		if err != nil {
+			// todo(hasan): should we log this error?
+			return ""
+		}
+		return r
+	}
+}

config/kafka/config.go

@@ -25,6 +25,14 @@ func Configure(p *config.Provider) {
 		r.References["broker_node_group_info.security_groups"] = config.Reference{
 			Type: "github.com/upbound/provider-aws/apis/ec2/v1beta1.SecurityGroup",
 		}
+		r.References["configuration_info.arn"] = config.Reference{
+			Type:      "Configuration",
+			Extractor: common.PathARNExtractor,
+		}
+		r.References["configuration_info.revision"] = config.Reference{
+			Type:      "Configuration",
+			Extractor: "GetConfigurationRevision()",
+		}
 		r.UseAsync = true
 	})
 }

examples/kafka/cluster.yaml

@@ -10,13 +10,20 @@ spec:
       - clientSubnetsRefs:
           - name: subnet-az1
           - name: subnet-az2
-        instanceType: kafka.m5.large
+        instanceType: kafka.t3.small
         securityGroupsRefs:
           - name: sg
         storageInfo:
           - ebsStorageInfo:
               - volumeSize: 1000
     clusterName: example
+    configurationInfo:
+      arnSelector:
+        matchLabels:
+          testing.upbound.io/example-name: example
+      revisionSelector:
+        matchLabels:
+          testing.upbound.io/example-name: example
     encryptionInfo:
       - encryptionAtRestKmsKeyArnSelector:
           matchLabels:
@@ -42,6 +49,24 @@ spec:
 
 ---
 
+apiVersion: kafka.aws.upbound.io/v1beta1
+kind: Configuration
+metadata:
+  labels:
+    testing.upbound.io/example-name: example
+  name: example
+spec:
+  forProvider:
+    kafkaVersions:
+      - 2.6.0
+    name: example
+    region: us-west-1
+    serverProperties: |
+      auto.create.topics.enable = true
+      delete.topic.enable = true
+
+---
+
 apiVersion: iam.aws.upbound.io/v1beta1
 kind: Role
 metadata: