Refactoring of kubernetes informers and local caches

internal/ingress/controller/store/configmap.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package store
+
+import (
+	"fmt"
+
+	apiv1 "k8s.io/api/core/v1"
+	"k8s.io/client-go/tools/cache"
+)
+
+// ConfigMapLister makes a Store that lists Configmaps.
+type ConfigMapLister struct {
+	cache.Store
+}
+
+// ByKey searches for a configmap in the local configmaps Store
+func (cml *ConfigMapLister) ByKey(key string) (*apiv1.ConfigMap, error) {
+	s, exists, err := cml.GetByKey(key)
+	if err != nil {
+		return nil, err
+	}
+	if !exists {
+		return nil, fmt.Errorf("configmap %v was not found", key)
+	}
+	return s.(*apiv1.ConfigMap), nil
+}