[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go
new file mode 100644
index 0000000..f455e40
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go
@@ -0,0 +1,123 @@
+// Copyright 2017 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 etcdhttp
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/raft"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+const (
+	PathMetrics = "/metrics"
+	PathHealth  = "/health"
+)
+
+// HandleMetricsHealth registers metrics and health handlers.
+func HandleMetricsHealth(mux *http.ServeMux, srv etcdserver.ServerV2) {
+	mux.Handle(PathMetrics, promhttp.Handler())
+	mux.Handle(PathHealth, NewHealthHandler(func() Health { return checkHealth(srv) }))
+}
+
+// HandlePrometheus registers prometheus handler on '/metrics'.
+func HandlePrometheus(mux *http.ServeMux) {
+	mux.Handle(PathMetrics, promhttp.Handler())
+}
+
+// NewHealthHandler handles '/health' requests.
+func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			w.Header().Set("Allow", http.MethodGet)
+			http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		h := hfunc()
+		d, _ := json.Marshal(h)
+		if h.Health != "true" {
+			http.Error(w, string(d), http.StatusServiceUnavailable)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+		w.Write(d)
+	}
+}
+
+var (
+	healthSuccess = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "health_success",
+		Help:      "The total number of successful health checks",
+	})
+	healthFailed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "health_failures",
+		Help:      "The total number of failed health checks",
+	})
+)
+
+func init() {
+	prometheus.MustRegister(healthSuccess)
+	prometheus.MustRegister(healthFailed)
+}
+
+// Health defines etcd server health status.
+// TODO: remove manual parsing in etcdctl cluster-health
+type Health struct {
+	Health string `json:"health"`
+}
+
+// TODO: server NOSPACE, etcdserver.ErrNoLeader in health API
+
+func checkHealth(srv etcdserver.ServerV2) Health {
+	h := Health{Health: "true"}
+
+	as := srv.Alarms()
+	if len(as) > 0 {
+		h.Health = "false"
+	}
+
+	if h.Health == "true" {
+		if uint64(srv.Leader()) == raft.None {
+			h.Health = "false"
+		}
+	}
+
+	if h.Health == "true" {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+		_, err := srv.Do(ctx, etcdserverpb.Request{Method: "QGET"})
+		cancel()
+		if err != nil {
+			h.Health = "false"
+		}
+	}
+
+	if h.Health == "true" {
+		healthSuccess.Inc()
+	} else {
+		healthFailed.Inc()
+	}
+	return h
+}