115 lines
3.1 KiB
Go
115 lines
3.1 KiB
Go
// Copyright 2016 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 grpcproxy
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import (
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"fmt"
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"io/ioutil"
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"math/rand"
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"net/http"
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"strings"
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"time"
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"github.com/prometheus/client_golang/prometheus"
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"go.etcd.io/etcd/etcdserver/api/etcdhttp"
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)
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var (
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watchersCoalescing = prometheus.NewGauge(prometheus.GaugeOpts{
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Namespace: "etcd",
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Subsystem: "grpc_proxy",
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Name: "watchers_coalescing_total",
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Help: "Total number of current watchers coalescing",
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})
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eventsCoalescing = prometheus.NewCounter(prometheus.CounterOpts{
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Namespace: "etcd",
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Subsystem: "grpc_proxy",
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Name: "events_coalescing_total",
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Help: "Total number of events coalescing",
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})
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cacheKeys = prometheus.NewGauge(prometheus.GaugeOpts{
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Namespace: "etcd",
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Subsystem: "grpc_proxy",
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Name: "cache_keys_total",
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Help: "Total number of keys/ranges cached",
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})
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cacheHits = prometheus.NewGauge(prometheus.GaugeOpts{
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Namespace: "etcd",
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Subsystem: "grpc_proxy",
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Name: "cache_hits_total",
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Help: "Total number of cache hits",
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})
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cachedMisses = prometheus.NewGauge(prometheus.GaugeOpts{
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Namespace: "etcd",
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Subsystem: "grpc_proxy",
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Name: "cache_misses_total",
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Help: "Total number of cache misses",
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})
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)
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func init() {
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prometheus.MustRegister(watchersCoalescing)
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prometheus.MustRegister(eventsCoalescing)
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prometheus.MustRegister(cacheKeys)
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prometheus.MustRegister(cacheHits)
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prometheus.MustRegister(cachedMisses)
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}
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// HandleMetrics performs a GET request against etcd endpoint and returns '/metrics'.
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func HandleMetrics(mux *http.ServeMux, c *http.Client, eps []string) {
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// random shuffle endpoints
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r := rand.New(rand.NewSource(int64(time.Now().Nanosecond())))
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if len(eps) > 1 {
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eps = shuffleEndpoints(r, eps)
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}
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pathMetrics := etcdhttp.PathMetrics
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mux.HandleFunc(pathMetrics, func(w http.ResponseWriter, r *http.Request) {
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target := fmt.Sprintf("%s%s", eps[0], pathMetrics)
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if !strings.HasPrefix(target, "http") {
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scheme := "http"
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if r.TLS != nil {
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scheme = "https"
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}
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target = fmt.Sprintf("%s://%s", scheme, target)
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}
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resp, err := c.Get(target)
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if err != nil {
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http.Error(w, "Internal server error", http.StatusInternalServerError)
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}
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defer resp.Body.Close()
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w.Header().Set("Content-Type", "text/plain; version=0.0.4")
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body, _ := ioutil.ReadAll(resp.Body)
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fmt.Fprintf(w, "%s", body)
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})
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}
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func shuffleEndpoints(r *rand.Rand, eps []string) []string {
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// copied from Go 1.9<= rand.Rand.Perm
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n := len(eps)
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p := make([]int, n)
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for i := 0; i < n; i++ {
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j := r.Intn(i + 1)
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p[i] = p[j]
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p[j] = i
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}
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neps := make([]string, n)
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for i, k := range p {
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neps[i] = eps[k]
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}
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return neps
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}
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