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106 lines
2.7 KiB
Go
106 lines
2.7 KiB
Go
/*
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Copyright 2014 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 small utility to just serve the hostname on TCP and/or UDP.
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package main
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import (
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"flag"
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"fmt"
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"log"
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"net"
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"net/http"
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"os"
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"os/signal"
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"syscall"
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"time"
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)
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var (
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doTCP = flag.Bool("tcp", false, "Serve raw over TCP.")
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doUDP = flag.Bool("udp", false, "Serve raw over UDP.")
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doHTTP = flag.Bool("http", true, "Serve HTTP.")
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port = flag.Int("port", 9376, "Port number.")
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)
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func main() {
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flag.Parse()
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if *doHTTP && (*doTCP || *doUDP) {
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log.Fatalf("Can't server TCP/UDP mode and HTTP mode at the same time")
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}
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hostname, err := os.Hostname()
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if err != nil {
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log.Fatalf("Error from os.Hostname(): %s", err)
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}
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if *doTCP {
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listener, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
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if err != nil {
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log.Fatalf("Error from net.Listen(): %s", err)
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}
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go func() {
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for {
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conn, err := listener.Accept()
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if err != nil {
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log.Fatalf("Error from Accept(): %s", err)
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}
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log.Printf("TCP request from %s", conn.RemoteAddr().String())
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conn.Write([]byte(hostname))
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conn.Close()
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}
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}()
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}
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if *doUDP {
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addr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", *port))
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if err != nil {
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log.Fatalf("Error from net.ResolveUDPAddr(): %s", err)
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}
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sock, err := net.ListenUDP("udp", addr)
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if err != nil {
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log.Fatalf("Error from ListenUDP(): %s", err)
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}
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go func() {
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var buffer [16]byte
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for {
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_, cliAddr, err := sock.ReadFrom(buffer[0:])
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if err != nil {
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log.Fatalf("Error from ReadFrom(): %s", err)
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}
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log.Printf("UDP request from %s", cliAddr.String())
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sock.WriteTo([]byte(hostname), cliAddr)
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}
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}()
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}
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if *doHTTP {
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http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
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log.Printf("HTTP request from %s", r.RemoteAddr)
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fmt.Fprintf(w, "%s", hostname)
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})
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go func() {
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// Run in a closure so http.ListenAndServe doesn't block
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log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", *port), nil))
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}()
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}
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log.Printf("Serving on port %d.\n", *port)
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signals := make(chan os.Signal)
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signal.Notify(signals, syscall.SIGTERM)
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sig := <-signals
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log.Printf("Shutting down after receiving signal: %s.\n", sig)
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log.Printf("Awaiting pod deletion.\n")
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time.Sleep(60 * time.Second)
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}
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