How do I stop a Listening server in Go

Question

I\'ve been trying to find a way to stop a listening server in Go gracefully. Because listen.Accept blocks it is necessary to close the listening socket to sign

Answer 1

Here's a simple way that's good enough for local development.

http://www.sergiotapia.me/how-to-stop-your-go-http-server/

---

package main

import (  
    "net/http"
    "os"

    "github.com/bmizerany/pat"
)

var mux = pat.New()

func main() {  
    mux.Get("/kill", http.HandlerFunc(kill))
    http.Handle("/", mux)
    http.ListenAndServe(":8080", nil)
}

func kill(w http.ResponseWriter, r *http.Request) {  
    os.Exit(0)
}

Answer 2

Something among these lines might work in this case, I hope:

// Listen for incoming connections
func (es *EchoServer) serve() {
        for {
                conn, err := es.listen.Accept()
                if err != nil {
                    if x, ok := err.(*net.OpError); ok && x.Op == "accept" { // We're done
                            log.Print("Stoping")
                            break
                    }

                    log.Printf("Accept failed: %v", err)
                    continue
                }
                go es.respond(conn.(*net.TCPConn))
        }
        es.done <- true
}

Answer 3

I would handle this by using es.done to send a signal before it closes the connection. In addition to the following code you'd need to create es.done with make(chan bool, 1) so that we can put a single value in it without blocking.

// Listen for incoming connections
func (es *EchoServer) serve() {
  for {
    conn, err := es.listen.Accept()
    if err != nil {
      select {
      case <-es.done:
        // If we called stop() then there will be a value in es.done, so
        // we'll get here and we can exit without showing the error.
      default:
        log.Printf("Accept failed: %v", err)
      }
      return
    }
    go es.respond(conn.(*net.TCPConn))
  }
}

// Stop the server by closing the listening listen
func (es *EchoServer) stop() {
  es.done <- true   // We can advance past this because we gave it buffer of 1
  es.listen.Close() // Now it the Accept will have an error above
}

Answer 4

Check some "is it time to stop" flag in your loop right after the accept() call, then flip it from your main, then connect to your listening port to get server socket "un-stuck". This is very similar to the old "self-pipe trick".