k3s/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go
Darren Shepherd f4ff2bf3a8 Update vendor
2020-06-06 22:38:12 -07:00

131 lines
3.5 KiB
Go

// 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)
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
}