Supports WAN and LAN Serf Bind Addresses. (#2468)

* * adding cli config and config file support for specifying the serf wan and lan bind addresses
* updating documentation for serf wan and lan options
Fixes #2007

* Cleans up some small things from #2380.

* Uses the bind default for the agent test for Serf WAN and LAN.

command/agent/agent.go

@@ -268,10 +268,6 @@ func (a *Agent) consulConfig() *consul.Config {
 	if a.config.NodeName != "" {
 		base.NodeName = a.config.NodeName
 	}
-	if a.config.BindAddr != "" {
-		base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.BindAddr
-		base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.BindAddr
-	}
 	if a.config.Ports.SerfLan != 0 {
 		base.SerfLANConfig.MemberlistConfig.BindPort = a.config.Ports.SerfLan
 		base.SerfLANConfig.MemberlistConfig.AdvertisePort = a.config.Ports.SerfLan
@@ -286,6 +282,17 @@ func (a *Agent) consulConfig() *consul.Config {
 			Port: a.config.Ports.Server,
 		}
 		base.RPCAddr = bindAddr
+
+		// Set the Serf configs using the old default behavior, we may
+		// override these in the code right below.
+		base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.BindAddr
+		base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.BindAddr
+	}
+	if a.config.SerfLanBindAddr != "" {
+		base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.SerfLanBindAddr
+	}
+	if a.config.SerfWanBindAddr != "" {
+		base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.SerfWanBindAddr
 	}
 	if a.config.AdvertiseAddr != "" {
 		base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr

command/agent/agent_test.go

@@ -124,6 +124,21 @@ func makeAgent(t *testing.T, conf *Config) (string, *Agent) {
 	return makeAgentLog(t, conf, nil)
 }
 
+func externalIP() (string, error) {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return "", fmt.Errorf("Unable to lookup network interfaces: %v", err)
+	}
+	for _, a := range addrs {
+		if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				return ipnet.IP.String(), nil
+			}
+		}
+	}
+	return "", fmt.Errorf("Unable to find a non-loopback interface")
+}
+
 func TestAgentStartStop(t *testing.T) {
 	dir, agent := makeAgent(t, nextConfig())
 	defer os.RemoveAll(dir)
@@ -154,6 +169,28 @@ func TestAgent_RPCPing(t *testing.T) {
 	}
 }
 
+func TestAgent_CheckSerfBindAddrsSettings(t *testing.T) {
+	c := nextConfig()
+	ip, err := externalIP()
+	if err != nil {
+		t.Fatalf("Unable to get a non-loopback IP: %v", err)
+	}
+	c.SerfLanBindAddr = ip
+	c.SerfWanBindAddr = ip
+	dir, agent := makeAgent(t, c)
+	defer os.RemoveAll(dir)
+	defer agent.Shutdown()
+
+	serfWanBind := agent.consulConfig().SerfWANConfig.MemberlistConfig.BindAddr
+	if serfWanBind != ip {
+		t.Fatalf("SerfWanBindAddr is should be a non-loopback IP not %s", serfWanBind)
+	}
+
+	serfLanBind := agent.consulConfig().SerfLANConfig.MemberlistConfig.BindAddr
+	if serfLanBind != ip {
+		t.Fatalf("SerfLanBindAddr is should be a non-loopback IP not %s", serfWanBind)
+	}
+}
 func TestAgent_CheckAdvertiseAddrsSettings(t *testing.T) {
 	c := nextConfig()
 	c.AdvertiseAddrs.SerfLan, _ = net.ResolveTCPAddr("tcp", "127.0.0.42:1233")

command/agent/command.go

@@ -96,6 +96,8 @@ func (c *Command) readConfig() *Config {
 
 	cmdFlags.StringVar(&cmdConfig.ClientAddr, "client", "", "address to bind client listeners to (DNS, HTTP, HTTPS, RPC)")
 	cmdFlags.StringVar(&cmdConfig.BindAddr, "bind", "", "address to bind server listeners to")
+	cmdFlags.StringVar(&cmdConfig.SerfWanBindAddr, "serf-wan-bind", "", "address to bind Serf WAN listeners to")
+	cmdFlags.StringVar(&cmdConfig.SerfLanBindAddr, "serf-lan-bind", "", "address to bind Serf LAN listeners to")
 	cmdFlags.IntVar(&cmdConfig.Ports.HTTP, "http-port", 0, "http port to use")
 	cmdFlags.IntVar(&cmdConfig.Ports.DNS, "dns-port", 0, "DNS port to use")
 	cmdFlags.StringVar(&cmdConfig.AdvertiseAddr, "advertise", "", "address to advertise instead of bind addr")

command/agent/command_test.go

@@ -126,6 +126,8 @@ func TestReadCliConfig(t *testing.T) {
 				"-data-dir", tmpDir,
 				"-node", `"a"`,
 				"-advertise-wan", "1.2.3.4",
+				"-serf-wan-bind", "4.3.2.1",
+				"-serf-lan-bind", "4.3.2.2",
 			},
 			ShutdownCh: shutdownCh,
 			Ui:         new(cli.MockUi),
@@ -135,6 +137,12 @@ func TestReadCliConfig(t *testing.T) {
 		if config.AdvertiseAddrWan != "1.2.3.4" {
 			t.Fatalf("expected -advertise-addr-wan 1.2.3.4 got %s", config.AdvertiseAddrWan)
 		}
+		if config.SerfWanBindAddr != "4.3.2.1" {
+			t.Fatalf("expected -serf-wan-bind 4.3.2.1 got %s", config.SerfWanBindAddr)
+		}
+		if config.SerfLanBindAddr != "4.3.2.2" {
+			t.Fatalf("expected -serf-lan-bind 4.3.2.2 got %s", config.SerfLanBindAddr)
+		}
 	}
 
 	// Test LeaveOnTerm and SkipLeaveOnInt defaults for server mode

command/agent/config.go

@@ -293,6 +293,18 @@ type Config struct {
 	// services (Gossip, Server RPC)
 	BindAddr string `mapstructure:"bind_addr"`
 
+	// SerfWanBindAddr is used to control the address we bind to.
+	// If not specified, the first private IP we find is used.
+	// This controls the address we use for cluster facing
+	// services (Gossip) Serf
+	SerfWanBindAddr string `mapstructure:"serf_wan_bind"`
+
+	// SerfLanBindAddr is used to control the address we bind to.
+	// If not specified, the first private IP we find is used.
+	// This controls the address we use for cluster facing
+	// services (Gossip) Serf
+	SerfLanBindAddr string `mapstructure:"serf_lan_bind"`
+
 	// AdvertiseAddr is the address we use for advertising our Serf,
 	// and Consul RPC IP. If not specified, bind address is used.
 	AdvertiseAddr string `mapstructure:"advertise_addr"`
@@ -1180,6 +1192,12 @@ func MergeConfig(a, b *Config) *Config {
 	if b.AdvertiseAddrWan != "" {
 		result.AdvertiseAddrWan = b.AdvertiseAddrWan
 	}
+	if b.SerfWanBindAddr != "" {
+		result.SerfWanBindAddr = b.SerfWanBindAddr
+	}
+	if b.SerfLanBindAddr != "" {
+		result.SerfLanBindAddr = b.SerfLanBindAddr
+	}
 	if b.TranslateWanAddrs == true {
 		result.TranslateWanAddrs = true
 	}

command/agent/config_test.go

@@ -179,8 +179,9 @@ func TestDecodeConfig(t *testing.T) {
 	}
 
 	// Server addrs
-	input = `{"ports": {"server": 8000}, "bind_addr": "127.0.0.2", "advertise_addr": "127.0.0.3"}`
+	input = `{"ports": {"server": 8000}, "bind_addr": "127.0.0.2", "advertise_addr": "127.0.0.3", "serf_lan_bind": "127.0.0.4", "serf_wan_bind": "52.54.55.56"}`
 	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
+
 	if err != nil {
 		t.Fatalf("err: %s", err)
 	}
@@ -189,6 +190,14 @@ func TestDecodeConfig(t *testing.T) {
 		t.Fatalf("bad: %#v", config)
 	}
 
+	if config.SerfWanBindAddr != "52.54.55.56" {
+		t.Fatalf("bad: %#v", config)
+	}
+
+	if config.SerfLanBindAddr != "127.0.0.4" {
+		t.Fatalf("bad: %#v", config)
+	}
+
 	if config.AdvertiseAddr != "127.0.0.3" {
 		t.Fatalf("bad: %#v", config)
 	}

website/source/docs/agent/options.html.markdown

@@ -103,6 +103,14 @@ will exit with an error at startup.
   Consul uses both TCP and UDP and the same port for both. If you
   have any firewalls, be sure to allow both protocols.
 
+* <a name="_serf_wan_bind"></a><a href="#_serf_wan_bind">`-serf-wan-bind`</a> - The address that should be bound to for Serf WAN gossip communications.
+  By default, the value follows the same rules as [`-bind` command-line flag](#_bind), and if this is not specified, the `-bind` option is used. This
+  is available in Consul 0.7.1 and later.
+
+* <a name="_serf_lan_bind"></a><a href="#_serf_lan_bind">`-serf-lan-bind`</a> - The address that should be bound to for Serf LAN gossip communications.
+  This is an IP address that should be reachable by all other LAN nodes in the cluster. By default, the value follows the same rules as
+  [`-bind` command-line flag](#_bind), and if this is not specified, the `-bind` option is used. This is available in Consul 0.7.1 and later.
+
 * <a name="_client"></a><a href="#_client">`-client`</a> - The address to which
   Consul will bind client interfaces,
   including the HTTP, DNS, and RPC servers. By default, this is "127.0.0.1",
@@ -428,6 +436,12 @@ Consul will not enable TLS for the HTTP API unless the `https` port has been ass
 * <a name="advertise_addr"></a><a href="#advertise_addr">`advertise_addr`</a> Equivalent to
   the [`-advertise` command-line flag](#_advertise).
 
+* <a name="serf_wan_bind"></a><a href="#serf_wan_bind">`serf_wan_bind`</a> Equivalent to
+  the [`-serf-wan-bind` command-line flag](#_serf_wan_bind).
+
+* <a name="serf_lan_bind"></a><a href="#serf_lan_bind">`serf_lan_bind`</a> Equivalent to
+  the [`-serf-lan-bind` command-line flag](#_serf_lan_bind).
+
 * <a name="advertise_addrs"></a><a href="#advertise_addrs">`advertise_addrs`</a> Allows to set
   the advertised addresses for SerfLan, SerfWan and RPC together with the port. This gives
   you more control than <a href="#_advertise">`-advertise`</a> or <a href="#_advertise-wan">`-advertise-wan`</a>