Add TLS flags

doddns-server/server.go

@@ -1,36 +1,69 @@
-package main
-
-import (
-	"flag"
-	"fmt"
-	"log"
-	"net"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strings"
-)
-
-// Handler responds a request with its IP address.
-func Handler(w http.ResponseWriter, r *http.Request) {
-	host, _, err := net.SplitHostPort(r.RemoteAddr)
-	if err != nil {
-		http.Error(w, "unable to get IP address", 500)
-		return
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	fportName = "port"
+	fcertName = "cert"
+	fkeyName  = "key"
+)
+
+// Handler responds a request with its IP address.
+func Handler(w http.ResponseWriter, r *http.Request) {
+	host, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		http.Error(w, "unable to get IP address", 500)
+		return
+	}
+	fmt.Fprintln(w, host)
+}
+
+func flagIsSet(name string) bool {
+	set := false
+	flag.Visit(func(f *flag.Flag) {
+		if f.Name == name {
+			set = true
+		}
+	})
+	return set
+}
+
+func main() {
+	fcert := flag.String(fcertName, "", "the TLS certificate to use")
+	fkey := flag.String(fkeyName, "", "the TLS key to use")
+	fport := flag.Uint("port", 18768, "the port to listen on")
+	flag.Parse()
+	fcertSet := flagIsSet(fcertName)
+	fkeySet := flagIsSet(fkeyName)
+	if fcertSet && !fkeySet {
+		log.Fatalf("%s set without %s", fcertName, fkeyName)
 	}
-	fmt.Fprintln(w, host)
-}
-
-func main() {
-	fport := flag.Uint("port", 18768, "the port to listen on")
-	flag.Parse()
-	logFile, err := os.OpenFile(filepath.Base(strings.TrimSuffix(os.Args[0],
-				filepath.Ext(os.Args[0])))+".log",
-		os.O_APPEND|os.O_CREATE, 0666)
-	if err != nil {
-		log.Fatal("unable to open log file")
-	}
-	log.SetOutput(logFile)
-	http.HandleFunc("/", Handler)
-	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", *fport), nil))
-}
+	if !fcertSet && fkeySet {
+		log.Fatalf("%s set without %s", fkeyName, fcertName)
+	}
+	tls := fcertSet && fkeySet
+	logFile, err := os.OpenFile(filepath.Base(strings.TrimSuffix(os.Args[0],
+				filepath.Ext(os.Args[0])))+".log",
+		os.O_APPEND|os.O_CREATE, 0666)
+	if err != nil {
+		log.Fatal("unable to open log file")
+	}
+	log.SetOutput(logFile)
+	http.HandleFunc("/", Handler)
+	addr := fmt.Sprintf(":%d", *fport)
+	if tls {
+		err = http.ListenAndServeTLS(addr, *fcert, *fkey, nil)
+	} else {
+		err = http.ListenAndServe(addr, nil)
+	}
+	log.Fatal(err)
+}