[VOL-4291] Rw-core updates for gRPC migration
Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/coreos/etcd/etcdserver/api/etcdhttp/metrics.go b/vendor/github.com/coreos/etcd/etcdserver/api/etcdhttp/metrics.go
new file mode 100644
index 0000000..2f6a0a7
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/etcdserver/api/etcdhttp/metrics.go
@@ -0,0 +1,130 @@
+// 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"
+
+ "github.com/coreos/etcd/etcdserver"
+ "github.com/coreos/etcd/etcdserver/etcdserverpb"
+ "github.com/coreos/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)
+ plog.Warningf("/health error (status code %d)", 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"
+ for _, v := range as {
+ plog.Warningf("/health error due to an alarm %s", v.String())
+ }
+ }
+
+ if h.Health == "true" {
+ if uint64(srv.Leader()) == raft.None {
+ h.Health = "false"
+ plog.Warningf("/health error; no leader (status code %d)", http.StatusServiceUnavailable)
+ }
+ }
+
+ 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"
+ plog.Warningf("/health error; QGET failed %v (status code %d)", err, http.StatusServiceUnavailable)
+ }
+ }
+
+ if h.Health == "true" {
+ healthSuccess.Inc()
+ plog.Infof("/health OK (status code %d)", http.StatusOK)
+ } else {
+ healthFailed.Inc()
+ }
+ return h
+}