From eb32ef2ea164cebb572f9a6e2ae4f7f8940f00ef Mon Sep 17 00:00:00 2001
From: HouzuoGuo <guohouzuo@gmail.com>
Date: Sun, 26 Nov 2017 17:13:17 +0100
Subject: [PATCH] teach http server to listen on port 80 when launched as
 "insecure http server" without tls

---
 daemon/httpd/httpd.go      | 12 ++++++------
 daemon/httpd/httpd_test.go |  2 +-
 launcher/config_test.go    |  2 +-
 main.go                    |  2 +-
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/daemon/httpd/httpd.go b/daemon/httpd/httpd.go
index 3d8d7e7d..9df9ef27 100644
--- a/daemon/httpd/httpd.go
+++ b/daemon/httpd/httpd.go
@@ -185,20 +185,20 @@ func (daemon *Daemon) Initialise() error {
 StartAndBlockNoTLS starts HTTP daemon and serve unencrypted connections. Blocks caller until StopNoTLS function is called.
 You may call this function only after having called Initialise()!
 */
-func (daemon *Daemon) StartAndBlockNoTLS() error {
+func (daemon *Daemon) StartAndBlockNoTLS(fallbackPort int) error {
 	/*
 		In order to determine the listener's port:
 		- On ElasticBeanstalk (and several other scenarios), listen on port number specified in environment PORT value.
-		- If TLS listener has not yet started, listen on the port specified by user configuration (prone to race condition).
-
-		In this way, caller of the function can determine whether to listen for TLS or ordinary traffic, one or the other.
+		- If TLS configuration does not exist, listen on the port specified by user configuration.
+		- If TLS configuration exists, then listen on the fallback port.
+		Not very elegant, but it should help to launch HTTP daemon in TLS only, TLS + HTTP, and HTTP only scenarios.
 	*/
 	var port int
 	if envPort := strings.TrimSpace(os.Getenv("PORT")); envPort == "" {
-		if daemon.serverWithTLS == nil {
+		if daemon.TLSCertPath == "" {
 			port = daemon.Port
 		} else {
-			return fmt.Errorf("httpd.StartAndBlockNoTLS: was about to listen on port %d but TLS listener is already using it", daemon.Port)
+			port = fallbackPort
 		}
 	} else {
 		iPort, err := strconv.Atoi(envPort)
diff --git a/daemon/httpd/httpd_test.go b/daemon/httpd/httpd_test.go
index 01d309b8..d96966f8 100644
--- a/daemon/httpd/httpd_test.go
+++ b/daemon/httpd/httpd_test.go
@@ -89,7 +89,7 @@ func TestHTTPD_StartAndBlock(t *testing.T) {
 	// HTTP daemon is expected to start in two seconds
 	var stoppedNormally bool
 	go func() {
-		if err := daemon.StartAndBlockNoTLS(); err != nil {
+		if err := daemon.StartAndBlockNoTLS(0); err != nil {
 			t.Fatal(err)
 		}
 		stoppedNormally = true
diff --git a/launcher/config_test.go b/launcher/config_test.go
index 8025f6e9..8f88aa6a 100644
--- a/launcher/config_test.go
+++ b/launcher/config_test.go
@@ -242,7 +242,7 @@ func TestConfig(t *testing.T) {
 	httpDaemon := config.GetHTTPD()
 	// HTTP daemon is expected to start in two seconds
 	go func() {
-		if err := httpDaemon.StartAndBlockNoTLS(); err != nil {
+		if err := httpDaemon.StartAndBlockNoTLS(0); err != nil {
 			t.Fatal(err)
 		}
 	}()
diff --git a/main.go b/main.go
index f48c5b07..6854970f 100644
--- a/main.go
+++ b/main.go
@@ -265,7 +265,7 @@ func main() {
 			}()
 		case launcher.InsecureHTTPDName:
 			go func() {
-				daemonErrs <- config.GetHTTPD().StartAndBlockNoTLS()
+				daemonErrs <- config.GetHTTPD().StartAndBlockNoTLS(80)
 			}()
 		case launcher.MaintenanceName:
 			go func() {