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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"
"path/filepath"
"runtime"
)
func Main() {
MainPath = filepath.Dir(findMainPath())
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)
}
}
// Find the path to package main by looking at the root Caller.
func findMainPath() string {
pc := make([]uintptr, 100)
n := runtime.Callers(2, pc)
frames := runtime.CallersFrames(pc[:n])
for {
frame, more := frames.Next()
// Tests won't have package main, instead they have testing.tRunner
if frame.Function == "main.main" || frame.Function == "testing.tRunner" {
return frame.File
}
if !more {
break
}
}
return ""
}
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")
})
}
}
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