Fix type errors from cached unstructured object

The cacheClient may have saved in memory an unstructured object which is
not assignable to the native struct type. In this situation do JSON
marshaling

Signed-off-by: Darren Shepherd <darren@acorn.io>

pkg/runtime/copy.go

@@ -1,13 +1,22 @@
 package runtime
 
 import (
+	"encoding/json"
 	"fmt"
 	"reflect"
 
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
 func CopyInto(dst, src runtime.Object) error {
+	if _, ok := src.(*unstructured.Unstructured); ok {
+		data, err := json.Marshal(src)
+		if err != nil {
+			return err
+		}
+		return json.Unmarshal(data, dst)
+	}
 	src = src.DeepCopyObject()
 	dstVal := reflect.ValueOf(dst)
 	srcVal := reflect.ValueOf(src)