genericapiserver: move packages

Towards a sane k8s.io/apiserver package structure.

pkg/genericapiserver/server/routes/metrics.go

@@ -0,0 +1,54 @@
+/*
+Copyright 2014 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 routes
+
+import (
+	"io"
+	"net/http"
+
+	apimetrics "k8s.io/apiserver/pkg/metrics"
+	etcdmetrics "k8s.io/apiserver/pkg/storage/etcd/metrics"
+	"k8s.io/kubernetes/pkg/genericapiserver/mux"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// DefaultMetrics installs the default prometheus metrics handler
+type DefaultMetrics struct{}
+
+// Install adds the DefaultMetrics handler
+func (m DefaultMetrics) Install(c *mux.APIContainer) {
+	c.NonSwaggerRoutes.Handle("/metrics", prometheus.Handler())
+}
+
+// MetricsWithReset install the prometheus metrics handler extended with support for the DELETE method
+// which resets the metrics.
+type MetricsWithReset struct{}
+
+// Install adds the MetricsWithReset handler
+func (m MetricsWithReset) Install(c *mux.APIContainer) {
+	defaultMetricsHandler := prometheus.Handler().ServeHTTP
+	c.NonSwaggerRoutes.HandleFunc("/metrics", func(w http.ResponseWriter, req *http.Request) {
+		if req.Method == "DELETE" {
+			apimetrics.Reset()
+			etcdmetrics.Reset()
+			io.WriteString(w, "metrics reset\n")
+			return
+		}
+		defaultMetricsHandler(w, req)
+	})
+}