Added greeting_type configuration option (flashmob#163)

config.go

@@ -45,6 +45,9 @@ type ServerConfig struct {
 	// Hostname will also be used to fill the 'Host' property when the "RCPT TO" address is
 	// addressed to just <postmaster>
 	Hostname string `json:"host_name"`
+	// GreetingType sets the greeting message which will be sent to clients.
+	// Currently, the options are "guerrilla" and "postfix". Defaults to "postfix".
+	GreetingType string `json:"greeting_type"`
 	// Listen interface specified in <ip>:<port> - defaults to 127.0.0.1:2525
 	ListenInterface string `json:"listen_interface"`
 	// MaxSize is the maximum size of an email that will be accepted for delivery.
@@ -155,6 +158,7 @@ const defaultMaxClients = 100
 const defaultTimeout = 30
 const defaultInterface = "127.0.0.1:2525"
 const defaultMaxSize = int64(10 << 20) // 10 Mebibytes
+const defaultGreetingType = "postfix"
 
 // Unmarshalls json data into AppConfig struct and any other initialization of the struct
 // also does validation, returns error if validation failed or something went wrong
@@ -288,6 +292,7 @@ func (c *AppConfig) setDefaults() error {
 		sc.MaxClients = defaultMaxClients
 		sc.Timeout = defaultTimeout
 		sc.MaxSize = defaultMaxSize
+		sc.GreetingType = defaultGreetingType
 		c.Servers = append(c.Servers, sc)
 	} else {
 		// make sure each server has defaults correctly configured
@@ -310,6 +315,9 @@ func (c *AppConfig) setDefaults() error {
 			if c.Servers[i].LogFile == "" {
 				c.Servers[i].LogFile = c.LogFile
 			}
+			if c.Servers[i].GreetingType == "" {
+				c.Servers[i].GreetingType = defaultGreetingType
+			}
 			// validate the server config
 			err = c.Servers[i].Validate()
 			if err != nil {
@@ -451,6 +459,11 @@ func (sc *ServerConfig) Validate() error {
 			errs = append(errs, fmt.Errorf("cannot use TLS config for [%s], %v", sc.ListenInterface, err))
 		}
 	}
+
+	if sc.GreetingType != "postfix" && sc.GreetingType != "guerrilla" {
+		errs = append(errs, errors.New("Unrecognised greeting_type. Valid options are 'postfix' and 'guerrilla'."))
+	}
+
 	if len(errs) > 0 {
 		return errs
 	}

goguerrilla.conf.sample

@@ -21,6 +21,7 @@
         {
             "is_enabled" : true,
             "host_name":"mail.test.com",
+            "greeting_type": "postfix",
             "max_size": 1000000,
             "timeout":180,
             "listen_interface":"127.0.0.1:25",
@@ -40,6 +41,7 @@
         {
             "is_enabled" : false,
             "host_name":"mail.test.com",
+            "greeting_type": "postfix",
             "max_size":1000000,
             "timeout":180,
             "listen_interface":"127.0.0.1:465",

server.go

@@ -367,9 +367,13 @@ func (s *server) handleClient(client *client) {
 	s.log().Infof("Handle client [%s], id: %d", client.RemoteIP, client.ID)
 
 	// Initial greeting
-	greeting := fmt.Sprintf("220 %s SMTP Guerrilla(%s) #%d (%d) %s",
-		sc.Hostname, Version, client.ID,
-		s.clientPool.GetActiveClientsCount(), time.Now().Format(time.RFC3339))
+	// GreetingType == "postfix" by default
+	greeting := fmt.Sprintf("220 %s ESMTP Postfix", sc.Hostname)
+	if sc.GreetingType == "guerrilla" {
+		greeting = fmt.Sprintf("220 %s SMTP Guerrilla(%s) #%d (%d) %s",
+			sc.Hostname, Version, client.ID,
+			s.clientPool.GetActiveClientsCount(), time.Now().Format(time.RFC3339))
+	}
 
 	helo := fmt.Sprintf("250 %s Hello", sc.Hostname)
 	// ehlo is a multi-line reply and need additional \r\n at the end

tests/guerrilla_test.go

@@ -88,6 +88,7 @@ var configJson = `
         {
             "is_enabled" : true,
             "host_name":"mail.guerrillamail.com",
+	    "greeting_type": "postfix",
             "max_size": 100017,
             "timeout":160,
             "listen_interface":"127.0.0.1:2526", 
@@ -104,6 +105,7 @@ var configJson = `
         {
             "is_enabled" : true,
             "host_name":"mail.guerrillamail.com",
+	    "greeting_type": "guerrilla",
             "max_size":1000001,
             "timeout":180,
             "listen_interface":"127.0.0.1:4654",
@@ -242,7 +244,7 @@ func TestGreeting(t *testing.T) {
 	}
 	defer cleanTestArtifacts(t)
 	if startErrors := app.Start(); startErrors == nil {
-		// 1. plaintext connection
+		// 1. plaintext connection, postfix
 		conn, err := net.Dial("tcp", config.Servers[0].ListenInterface)
 		if err != nil {
 			// handle error
@@ -256,14 +258,14 @@ func TestGreeting(t *testing.T) {
 			t.Error(err)
 			t.FailNow()
 		} else {
-			expected := "220 mail.guerrillamail.com SMTP Guerrilla"
+			expected := "220 mail.guerrillamail.com ESMTP Postfix"
 			if strings.Index(greeting, expected) != 0 {
 				t.Error("Server[1] did not have the expected greeting prefix", expected)
 			}
 		}
 		_ = conn.Close()
 
-		// 2. tls connection
+		// 2. tls connection, guerrilla
 		//	roots, err := x509.SystemCertPool()
 		conn, err = tls.Dial("tcp", config.Servers[1].ListenInterface, &tls.Config{