mirror of
https://github.com/k3s-io/k3s.git
synced 2024-06-07 19:41:36 +00:00
131 lines
3.5 KiB
Go
131 lines
3.5 KiB
Go
// Copyright 2017 The etcd Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package etcdhttp
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import (
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"context"
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"encoding/json"
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"net/http"
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"time"
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"go.etcd.io/etcd/etcdserver"
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"go.etcd.io/etcd/etcdserver/etcdserverpb"
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"go.etcd.io/etcd/raft"
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"github.com/prometheus/client_golang/prometheus"
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"github.com/prometheus/client_golang/prometheus/promhttp"
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)
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const (
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PathMetrics = "/metrics"
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PathHealth = "/health"
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)
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// HandleMetricsHealth registers metrics and health handlers.
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func HandleMetricsHealth(mux *http.ServeMux, srv etcdserver.ServerV2) {
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mux.Handle(PathMetrics, promhttp.Handler())
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mux.Handle(PathHealth, NewHealthHandler(func() Health { return checkHealth(srv) }))
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}
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// HandlePrometheus registers prometheus handler on '/metrics'.
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func HandlePrometheus(mux *http.ServeMux) {
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mux.Handle(PathMetrics, promhttp.Handler())
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}
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// NewHealthHandler handles '/health' requests.
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func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
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return func(w http.ResponseWriter, r *http.Request) {
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if r.Method != http.MethodGet {
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w.Header().Set("Allow", http.MethodGet)
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http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
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plog.Warningf("/health error (status code %d)", http.StatusMethodNotAllowed)
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return
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}
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h := hfunc()
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d, _ := json.Marshal(h)
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if h.Health != "true" {
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http.Error(w, string(d), http.StatusServiceUnavailable)
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return
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}
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w.WriteHeader(http.StatusOK)
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w.Write(d)
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}
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}
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var (
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healthSuccess = prometheus.NewCounter(prometheus.CounterOpts{
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Namespace: "etcd",
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Subsystem: "server",
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Name: "health_success",
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Help: "The total number of successful health checks",
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})
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healthFailed = prometheus.NewCounter(prometheus.CounterOpts{
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Namespace: "etcd",
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Subsystem: "server",
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Name: "health_failures",
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Help: "The total number of failed health checks",
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})
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)
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func init() {
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prometheus.MustRegister(healthSuccess)
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prometheus.MustRegister(healthFailed)
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}
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// Health defines etcd server health status.
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// TODO: remove manual parsing in etcdctl cluster-health
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type Health struct {
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Health string `json:"health"`
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}
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// TODO: server NOSPACE, etcdserver.ErrNoLeader in health API
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func checkHealth(srv etcdserver.ServerV2) Health {
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h := Health{Health: "true"}
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as := srv.Alarms()
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if len(as) > 0 {
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h.Health = "false"
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for _, v := range as {
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plog.Warningf("/health error due to an alarm %s", v.String())
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}
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}
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if h.Health == "true" {
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if uint64(srv.Leader()) == raft.None {
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h.Health = "false"
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plog.Warningf("/health error; no leader (status code %d)", http.StatusServiceUnavailable)
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}
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}
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if h.Health == "true" {
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ctx, cancel := context.WithTimeout(context.Background(), time.Second)
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_, err := srv.Do(ctx, etcdserverpb.Request{Method: "QGET"})
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cancel()
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if err != nil {
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h.Health = "false"
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plog.Warningf("/health error; QGET failed %v (status code %d)", err, http.StatusServiceUnavailable)
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}
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}
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if h.Health == "true" {
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healthSuccess.Inc()
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plog.Infof("/health OK (status code %d)", http.StatusOK)
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} else {
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healthFailed.Inc()
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}
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return h
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}
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