vendor/google.golang.org/appengine/internal/main_vm.go


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// Copyright 2011 Google Inc. All rights reserved.
// Use of this source code is governed by the Apache 2.0
// license that can be found in the LICENSE file.

// +build !appengine

package internal

import (
    "io"
    "log"
    "net/http"
    "net/url"
    "os"
)

func Main() {
    installHealthChecker(http.DefaultServeMux)

    port := "8080"
    if s := os.Getenv("PORT"); s != "" {
        port = s
    }

    host := ""
    if IsDevAppServer() {
        host = "127.0.0.1"
    }
    if err := http.ListenAndServe(host+":"+port, http.HandlerFunc(handleHTTP)); err != nil {
        log.Fatalf("http.ListenAndServe: %v", err)
    }
}

func installHealthChecker(mux *http.ServeMux) {
    // If no health check handler has been installed by this point, add a trivial one.
    const healthPath = "/_ah/health"
    hreq := &http.Request{
        Method: "GET",
        URL: &url.URL{
            Path: healthPath,
        },
    }
    if _, pat := mux.Handler(hreq); pat != healthPath {
        mux.HandleFunc(healthPath, func(w http.ResponseWriter, r *http.Request) {
            io.WriteString(w, "ok")
        })
    }
}