Add configuration option to specify a separate address for advertising on the wan

command/agent/agent.go

@@ -127,6 +127,15 @@ func Create(config *Config, logOutput io.Writer) (*Agent, error) {
 		config.AdvertiseAddr = ip.String()
 	}
 
+	// Try to get an advertise address for the wan
+	if config.AdvertiseAddrWan != "" {
+		if ip := net.ParseIP(config.AdvertiseAddrWan); ip == nil {
+			return nil, fmt.Errorf("Failed to parse advertise address for wan: %v", config.AdvertiseAddrWan)
+		}
+	} else {
+		config.AdvertiseAddrWan = config.AdvertiseAddr
+	}
+
 	agent := &Agent{
 		config:        config,
 		logger:        log.New(logOutput, "", log.LstdFlags),
@@ -225,7 +234,11 @@ func (a *Agent) consulConfig() *consul.Config {
 	}
 	if a.config.AdvertiseAddr != "" {
 		base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr
-		base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr
+		if a.config.AdvertiseAddrWan != "" {
+			base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrWan
+		} else {
+			base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr
+		}
 		base.RPCAdvertise = &net.TCPAddr{
 			IP:   net.ParseIP(a.config.AdvertiseAddr),
 			Port: a.config.Ports.Server,

command/agent/config.go

@@ -142,6 +142,10 @@ type Config struct {
 	// and Consul RPC IP. If not specified, bind address is used.
 	AdvertiseAddr string `mapstructure:"advertise_addr"`
 
+	// AdvertiseAddrWan is the address we use for advertising our
+	// Serf WAN IP. If not specified, the general advertise address is used.
+	AdvertiseAddrWan string `mapstructure:"advertise_addr_wan"`
+
 	// Port configurations
 	Ports PortConfig
 
@@ -799,6 +803,9 @@ func MergeConfig(a, b *Config) *Config {
 	if b.AdvertiseAddr != "" {
 		result.AdvertiseAddr = b.AdvertiseAddr
 	}
+	if b.AdvertiseAddrWan != "" {
+		result.AdvertiseAddrWan = b.AdvertiseAddrWan
+	}
 	if b.Server == true {
 		result.Server = b.Server
 	}

command/agent/config_test.go

@@ -190,10 +190,27 @@ func TestDecodeConfig(t *testing.T) {
 		t.Fatalf("bad: %#v", config)
 	}
 
+	if config.AdvertiseAddrWan != "" {
+		t.Fatalf("bad: %#v", config)
+	}
+
 	if config.Ports.Server != 8000 {
 		t.Fatalf("bad: %#v", config)
 	}
 
+	// Advertise address for wan
+	input = `{"advertise_addr_wan": "127.0.0.5"}`
+	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if config.AdvertiseAddr != "" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.AdvertiseAddrWan != "127.0.0.5" {
+		t.Fatalf("bad: %#v", config)
+	}
+
 	// leave_on_terminate
 	input = `{"leave_on_terminate": true}`
 	config, err = DecodeConfig(bytes.NewReader([]byte(input)))