[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/coreos/etcd/etcdserver/api/v2http/metrics.go b/vendor/github.com/coreos/etcd/etcdserver/api/v2http/metrics.go
new file mode 100644
index 0000000..fdfb0c6
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/etcdserver/api/v2http/metrics.go
@@ -0,0 +1,96 @@
+// Copyright 2015 The etcd 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 v2http
+
+import (
+	"strconv"
+	"time"
+
+	"net/http"
+
+	etcdErr "github.com/coreos/etcd/error"
+	"github.com/coreos/etcd/etcdserver"
+	"github.com/coreos/etcd/etcdserver/api/v2http/httptypes"
+	"github.com/coreos/etcd/etcdserver/etcdserverpb"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	incomingEvents = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "http",
+			Name:      "received_total",
+			Help:      "Counter of requests received into the system (successfully parsed and authd).",
+		}, []string{"method"})
+
+	failedEvents = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "http",
+			Name:      "failed_total",
+			Help:      "Counter of handle failures of requests (non-watches), by method (GET/PUT etc.) and code (400, 500 etc.).",
+		}, []string{"method", "code"})
+
+	successfulEventsHandlingTime = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: "etcd",
+			Subsystem: "http",
+			Name:      "successful_duration_seconds",
+			Help:      "Bucketed histogram of processing time (s) of successfully handled requests (non-watches), by method (GET/PUT etc.).",
+			Buckets:   prometheus.ExponentialBuckets(0.0005, 2, 13),
+		}, []string{"method"})
+)
+
+func init() {
+	prometheus.MustRegister(incomingEvents)
+	prometheus.MustRegister(failedEvents)
+	prometheus.MustRegister(successfulEventsHandlingTime)
+}
+
+func reportRequestReceived(request etcdserverpb.Request) {
+	incomingEvents.WithLabelValues(methodFromRequest(request)).Inc()
+}
+
+func reportRequestCompleted(request etcdserverpb.Request, response etcdserver.Response, startTime time.Time) {
+	method := methodFromRequest(request)
+	successfulEventsHandlingTime.WithLabelValues(method).Observe(time.Since(startTime).Seconds())
+}
+
+func reportRequestFailed(request etcdserverpb.Request, err error) {
+	method := methodFromRequest(request)
+	failedEvents.WithLabelValues(method, strconv.Itoa(codeFromError(err))).Inc()
+}
+
+func methodFromRequest(request etcdserverpb.Request) string {
+	if request.Method == "GET" && request.Quorum {
+		return "QGET"
+	}
+	return request.Method
+}
+
+func codeFromError(err error) int {
+	if err == nil {
+		return http.StatusInternalServerError
+	}
+	switch e := err.(type) {
+	case *etcdErr.Error:
+		return (*etcdErr.Error)(e).StatusCode()
+	case *httptypes.HTTPError:
+		return (*httptypes.HTTPError)(e).Code
+	default:
+		return http.StatusInternalServerError
+	}
+}