Merge pull request #4 from gptankit/master_tls_management

Improvements to optional tls management

listener.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"crypto/rand"
+	"crypto/tls"
+	"model"
+	"net"
+	"time"
+)
+
+func getListener(sqp model.ServiceQProperties) (net.Listener, error) {
+
+	transport := "tcp"
+	addr := ":" + sqp.ListenerPort
+	certificate := sqp.SSLCertificateFile
+	key := sqp.SSLPrivateKeyFile
+
+	if !sqp.SSLEnabled {
+		return newListener(transport, addr)
+	} else {
+		return newListener(transport, addr, applyTLS(certificate, key))
+	}
+}
+
+func newListener(transport string, addr string, options ...func(*net.Listener) error) (net.Listener, error) {
+
+	listener, err := net.Listen(transport, addr)
+	if err != nil {
+		return listener, err
+	}
+
+	for _, option := range options {
+		err = option(&listener)
+		if err != nil {
+			return listener, err // further options won't be executed
+		}
+	}
+
+	return listener, nil
+}
+
+func applyTLS(certificate string, key string) func(*net.Listener) error {
+
+	return func(l *net.Listener) error {
+
+		cert, err := tls.LoadX509KeyPair(certificate, key)
+		if err != nil {
+			return err
+		}
+
+		tlsConfig := &tls.Config{
+			Certificates: []tls.Certificate{cert},
+			ServerName:   "serviceq",
+			NextProtos:   []string{"http/1.1", "http/1.0"},
+			Time:         time.Now,
+			Rand:         rand.Reader,
+		}
+		tlsConfig.BuildNameToCertificate()
+		tlsConfig.PreferServerCipherSuites = true
+
+		*l = tls.NewListener(*l, tlsConfig)
+		return nil
+	}
+}

serviceq.go

@@ -1,8 +1,6 @@
 package main
 
 import (
-	"crypto/rand"
-	"crypto/tls"
 	"fmt"
 	"model"
 	"net"
@@ -35,28 +33,6 @@ func main() {
 	}
 }
 
-func getListener(sqp model.ServiceQProperties) (net.Listener, error) {
-
-	if sqp.SSLEnabled {
-		cert, err := tls.LoadX509KeyPair(sqp.SSLCertificateFile, sqp.SSLPrivateKeyFile)
-		if err != nil {
-			return nil, err
-		}
-		tlsConfig := &tls.Config{
-			Certificates: []tls.Certificate{cert},
-			ServerName:   "serviceq",
-			NextProtos:   []string{"http/1.1", "http/1.0"},
-			Time:         time.Now,
-			Rand:         rand.Reader,
-		}
-		tlsConfig.BuildNameToCertificate()
-		tlsConfig.PreferServerCipherSuites = true
-		return tls.Listen("tcp", ":"+sqp.ListenerPort, tlsConfig)
-	} else {
-		return net.Listen("tcp", ":"+sqp.ListenerPort)
-	}
-}
-
 func listenActive(listener net.Listener, creq chan interface{}, cwork chan int, sqp *model.ServiceQProperties) {
 
 	for {