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Want to stop http server remotely

开发者 https://www.devze.com 2023-03-20 04:32 出处:网络
I want to stop the http server remotely (which I can do), but I also want to receive a message indicating that it has been stopped after it has been stopped. That is causing me some problems. The only

I want to stop the http server remotely (which I can do), but I also want to receive a message indicating that it has been stopped after it has been stopped. That is causing me some problems. The only solution that I could find is as shown below, which I do not consider ideal. Can anyone provide a better solution. The problem is that the final message sent to the client is not getting through unless I use the goroutine as shown at the end "go func() {".

Code is as follows:


//*************
func stopServer(ohtWriter http.ResponseWriter, phtRequest *http.Request) {// Stop The Server
//*************

    var iBytesSent  int
    var oOsError    os.Error
    var sErmes  string

    println("Stopping S开发者_Python百科erver")

    iBytesSent,oOsError = ohtWriter.Write([]byte("Message from server - server now stopped."))

    if oOsError != nil {
        sErmes = ". Error = " +oOsError.String()
    } else {
        sErmes = ". No error on write"
    }

    println("stopServer: Bytes sent = " +strconv.Itoa(iBytesSent) +sErmes)

    ohtFlusher, tCanFlush := ohtWriter.(http.Flusher)
    if tCanFlush {
        ohtFlusher.Flush()
    }

    go func() {
        time.Sleep(3e9)
        os.Exit(0)
    }()
}


Yeah I think without support from the http package, a graceful shutdown is not really possible. This is maybe a little bit less cringe-worthy, but will still slam closed any other concurrent requests in flight at the time of this request. Maybe try filing a feature request on the Go issue tracker. Better yet, open up the http package, and add a graceful shutdown method, and submit it.

Edit: I guess if you control all of the http.Handlers in your app, you could keep a count of in-flight requests (using appropriate thread synchronization), and modify the code below to a) refuse new connections once "shutdown" is called and b) wait for all in-flight requests to complete before shutting down...

package main

import (
    "http"
    "os"
    "io"
    "log"
    "strconv"
)

func main() {
    http.HandleFunc("/", ServeHTTP)
    http.ListenAndServe(":8081", nil)
}

const responseString = "Shutting down\n"

func ServeHTTP(w http.ResponseWriter, req *http.Request) {
    w.Header().Set("Content-Type", "text/plain; charset=utf-8")
    w.Header().Set("Content-Length", strconv.Itoa(len(responseString)))
    io.WriteString(w, responseString)

    f, canFlush := w.(http.Flusher)
    if canFlush {
        f.Flush()
    }

    conn, _, err := w.(http.Hijacker).Hijack()
    if err != nil {
        log.Fatalf("error while shutting down: %v", err)
    }

    conn.Close()

    log.Println("Shutting down")
    os.Exit(0)
}   


Haven't tried it yet, but using http.ServerConn directly might work.


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)
}
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