redirect non-tls port

main.go

@@ -2,9 +2,11 @@ package main
 
 import (
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"strconv"
+	"strings"
 )
 
 const usage = "servetls <cert file> <key file>"
@@ -18,7 +20,17 @@ func main() {
 
 	http.HandleFunc("/", handler)
 
-	port := 8443
+	tlsPort := 8443
+	if os.Getenv("TLS_PORT") != "" {
+		p, err := strconv.Atoi(os.Getenv("TLS_PORT"))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "could not parse TLS_PORT variable: %s\n", os.Getenv("TLS_PORT"))
+			os.Exit(1)
+		}
+		tlsPort = p
+	}
+
+	port := 8000
 	if os.Getenv("PORT") != "" {
 		p, err := strconv.Atoi(os.Getenv("PORT"))
 		if err != nil {
@@ -27,8 +39,22 @@ func main() {
 		}
 		port = p
 	}
-	addr := fmt.Sprintf(":%d", port)
-	fmt.Printf("serving on %s", addr)
+
+	go func() {
+		b := &bouncer{tlsPort}
+
+		sm := http.NewServeMux()
+		sm.Handle("/", b)
+
+		addr := fmt.Sprintf(":%d", port)
+		if err := http.ListenAndServe(addr, sm); err != nil {
+			panic(err)
+		}
+	}()
+
+	fmt.Printf("redirecting on :%d\n", port)
+	fmt.Printf("serving on :%d\n", tlsPort)
+	addr := fmt.Sprintf(":%d", tlsPort)
 	err := http.ListenAndServeTLS(addr, cert, key, nil)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", err)
@@ -39,3 +65,23 @@ func main() {
 func handler(w http.ResponseWriter, req *http.Request) {
 	fmt.Fprintf(w, "if you see this without complaints things are likely set up correctly\n")
 }
+
+type bouncer struct {
+	port int
+}
+
+func (b *bouncer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	var host string
+	var err error
+	if strings.Contains(req.Host, ":") {
+		host, _, err = net.SplitHostPort(req.Host)
+		if err != nil {
+			http.Error(w, "couldn't parse hostname from requeest", http.StatusBadRequest)
+			return
+		}
+	} else {
+		host = req.Host
+	}
+	url := fmt.Sprintf("https://%s:%d/", host, b.port)
+	http.Redirect(w, req, url, http.StatusMovedPermanently)
+}