Store ns in db

backend/src/apiserver/resource/model_converter.go

@@ -200,17 +200,15 @@ func (r *ResourceManager) toModelResourceReferences(
 			return nil, util.Wrap(err, "Failed to find the referred resource")
 		}
 		//TODO(gaoning777) further investigation: Is the plain namespace a good option?  maybe uuid for distinctness even with namespace deletion/recreation.
-		if apiRef.Key.Type != api.ResourceType_NAMESPACE {
-			modelRef := &model.ResourceReference{
-				ResourceUUID:  resourceId,
-				ResourceType:  resourceType,
-				ReferenceUUID: apiRef.Key.Id,
-				ReferenceName: referenceName,
-				ReferenceType: modelReferenceType,
-				Relationship:  modelRelationship,
-			}
-			modelRefs = append(modelRefs, modelRef)
-		}
+		modelRef := &model.ResourceReference{
+			ResourceUUID:  resourceId,
+			ResourceType:  resourceType,
+			ReferenceUUID: apiRef.Key.Id,
+			ReferenceName: referenceName,
+			ReferenceType: modelReferenceType,
+			Relationship:  modelRelationship,
+		}
+		modelRefs = append(modelRefs, modelRef)
 	}
 	return modelRefs, nil
 }

backend/src/apiserver/resource/model_converter_test.go

@@ -206,7 +206,7 @@ func TestToModelResourceReferences_NamespaceRef(t *testing.T) {
 		{Key: &api.ResourceKey{Type: api.ResourceType_NAMESPACE, Id: "e1"}, Relationship: api.Relationship_OWNER},
 	})
 	assert.Nil(t, err)
-	assert.Equal(t, 0, len(modelRefs))
+	assert.Equal(t, 1, len(modelRefs))
 }
 
 func TestToModelResourceReferences_UnknownRelationship(t *testing.T) {

backend/src/apiserver/server/api_converter.go

@@ -268,6 +268,8 @@ func toApiResourceType(modelType common.ResourceType) api.ResourceType {
 		return api.ResourceType_JOB
 	case common.PipelineVersion:
 		return api.ResourceType_PIPELINE_VERSION
+	case common.Namespace:
+		return api.ResourceType_NAMESPACE
 	default:
 		return api.ResourceType_UNKNOWN_RESOURCE_TYPE
 	}

backend/src/apiserver/storage/resource_reference_store.go

@@ -64,6 +64,10 @@ func (s *ResourceReferenceStore) checkReferenceExist(tx *sql.Tx, referenceId str
 		selectBuilder = sq.Select("1").From("experiments").Where(sq.Eq{"uuid": referenceId})
 	case common.PipelineVersion:
 		selectBuilder = sq.Select("1").From("pipeline_versions").Where(sq.Eq{"uuid": referenceId})
+	case common.Namespace:
+		// This function is called to check the data validity when the data are transformed according to the DB schema.
+		// Since there is not a separate table to store the namespace data, thus always returning true.
+		return true
 	default:
 		return false
 	}