Return empty mapping for non scaling ops requests (#64)

Signed-off-by: Tamal Saha <[email protected]>

api/constants.go

@@ -16,7 +16,11 @@ limitations under the License.
 
 package api
 
-import core "k8s.io/api/core/v1"
+import (
+	"errors"
+
+	core "k8s.io/api/core/v1"
+)
 
 type PodRole string
 
@@ -56,6 +60,8 @@ const (
 	PodRoleRouters          PodRole = "routers"
 )
 
+var ErrMissingRefObject = errors.New("referenced object not found")
+
 type ReplicaList map[PodRole]int64
 
 type PodInfo struct {

ops.kubedb.com/v1alpha1/scale.go

@@ -18,9 +18,10 @@ package v1alpha1
 
 import (
 	"errors"
-	"fmt"
 	"strings"
 
+	"kmodules.xyz/resource-metrics/api"
+
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
@@ -69,7 +70,14 @@ func extractReferencedObject(opsObj map[string]interface{}, refDbPath ...string)
 	}
 	dbObj, found, _ := unstructured.NestedMap(opsObj, refDbPath...)
 	if !found {
-		return nil, errors.New("referenced db object not found")
+		return nil, api.ErrMissingRefObject
+	}
+
+	_, foundApiVersion := dbObj["apiVersion"]
+	_, foundKind := dbObj["kind"]
+	_, foundMetadata := dbObj["metadata"]
+	if !foundApiVersion || !foundKind || !foundMetadata {
+		return nil, api.ErrMissingRefObject
 	}
 
 	return dbObj, nil
@@ -106,5 +114,5 @@ func getMapping(opsObj OpsReqObject, opsMapper OpsPathMapper) (map[OpsReqPath]Re
 		return opsMapper.VolumeExpansionPathMapping(), nil
 	}
 
-	return nil, fmt.Errorf("scaling type `%s` not supported", scalingType)
+	return nil, nil
 }