debugger/go/skdebugger/main.go

package main

import (
	"flag"
	"html/template"
	"net/http"
	"path/filepath"
	"runtime"

	"github.com/gorilla/mux"
	"github.com/skia-dev/glog"
	"go.skia.org/infra/go/common"
	"go.skia.org/infra/go/httputils"
	"go.skia.org/infra/go/influxdb"
)

// flags
var (
	local        = flag.Bool("local", false, "Running locally if true. As opposed to in production.")
	port         = flag.String("port", ":8000", "HTTP service address (e.g., ':8000')")
	resourcesDir = flag.String("resources_dir", "", "The directory to find templates, JS, and CSS files. If blank the current directory will be used.")

	influxHost     = flag.String("influxdb_host", influxdb.DEFAULT_HOST, "The InfluxDB hostname.")
	influxUser     = flag.String("influxdb_name", influxdb.DEFAULT_USER, "The InfluxDB username.")
	influxPassword = flag.String("influxdb_password", influxdb.DEFAULT_PASSWORD, "The InfluxDB password.")
	influxDatabase = flag.String("influxdb_database", influxdb.DEFAULT_DATABASE, "The InfluxDB database.")
)

var (
	templates *template.Template
)

func loadTemplates() {
	templates = template.Must(template.New("").ParseFiles(
		filepath.Join(*resourcesDir, "templates/index.html"),
	))
}

func templateHandler(name string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/html")
		w.Header().Set("Access-Control-Allow-Origin", "*")
		if *local {
			loadTemplates()
		}
		if err := templates.ExecuteTemplate(w, name, struct{}{}); err != nil {
			glog.Errorln("Failed to expand template:", err)
		}
	}
}

func Init() {
	if *resourcesDir == "" {
		_, filename, _, _ := runtime.Caller(0)
		*resourcesDir = filepath.Join(filepath.Dir(filename), "../..")
	}
	loadTemplates()
}

func makeResourceHandler() func(http.ResponseWriter, *http.Request) {
	fileServer := http.FileServer(http.Dir(*resourcesDir))
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Cache-Control", "max-age=300")
		w.Header().Set("Access-Control-Allow-Origin", "*")
		fileServer.ServeHTTP(w, r)
	}
}

func main() {
	defer common.LogPanic()
	common.InitWithMetrics2("debugger", influxHost, influxUser, influxPassword, influxDatabase, local)
	Init()

	router := mux.NewRouter()
	router.PathPrefix("/res/").HandlerFunc(makeResourceHandler())
	router.HandleFunc("/", templateHandler("index.html"))
	http.Handle("/", httputils.LoggingGzipRequestResponse(router))

	glog.Infoln("Ready to serve.")
	glog.Fatal(http.ListenAndServe(*port, nil))
}