Merge branch '29-golang-1.12' into 'master'

Rewrite main func for go111 runtime

Closes #29

See merge request tnir/docs.djangoproject.jp!24

Author: tnir

redirect.go

@@ -1,7 +1,10 @@
 package main
 
 import (
+	"fmt"
+	"log"
 	"net/http"
+	"os"
 	"regexp"
 	"strings"
 )
@@ -75,4 +78,13 @@ func redirect(w http.ResponseWriter, r *http.Request) {
 
 func main() {
 	http.HandleFunc("/", redirect)
+
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+		log.Printf("Defaulting to port %s", port)
+	}
+
+	log.Printf("Listening on port %s", port)
+	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
 }