86 lines
2.2 KiB
Go
86 lines
2.2 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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*/
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// A webserver that only serves a 404 page. Used as a default backend.
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package main
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import (
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"context"
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"flag"
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"fmt"
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"net/http"
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"os"
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"os/signal"
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"strconv"
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"syscall"
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"time"
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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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var port = flag.Int("port", 8080, "Port number to serve default backend 404 page.")
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func init() {
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// Register the summary and the histogram with Prometheus's default registry.
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prometheus.MustRegister(requestCount)
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prometheus.MustRegister(requestDuration)
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}
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func main() {
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flag.Parse()
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http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
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start := time.Now()
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w.WriteHeader(http.StatusNotFound)
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fmt.Fprint(w, "default backend - 404")
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duration := time.Now().Sub(start).Seconds() * 1e3
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proto := strconv.Itoa(r.ProtoMajor)
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proto = proto + "." + strconv.Itoa(r.ProtoMinor)
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requestCount.WithLabelValues(proto).Inc()
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requestDuration.WithLabelValues(proto).Observe(duration)
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})
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http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
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w.WriteHeader(http.StatusOK)
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fmt.Fprint(w, "ok")
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})
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http.Handle("/metrics", promhttp.Handler())
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srv := &http.Server{
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Addr: fmt.Sprintf(":%d", *port),
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}
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go func() {
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err := srv.ListenAndServe()
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if err != http.ErrServerClosed {
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fmt.Fprintf(os.Stderr, "could not start http server: %s\n", err)
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os.Exit(1)
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}
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}()
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stop := make(chan os.Signal, 1)
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signal.Notify(stop, syscall.SIGTERM)
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<-stop
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ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
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defer cancel()
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err := srv.Shutdown(ctx)
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if err != nil {
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fmt.Fprintf(os.Stderr, "could not graceful shutdown http server: %s\n", err)
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}
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}
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