agent: Adding address configurations

command/agent/config.go

@@ -29,6 +29,15 @@ type PortConfig struct {
 	Server  int // Server internal RPC
 }
 
+// AddressConfig is used to provide address overrides
+// for specific services. By default, either ClientAddress
+// or ServerAddress is used.
+type AddressConfig struct {
+	DNS  string // DNS Query interface
+	HTTP string // HTTP API
+	RPC  string // CLI RPC
+}
+
 // DNSConfig is used to fine tune the DNS sub-system.
 // It can be used to control cache values, and stale
 // reads
@@ -117,6 +126,9 @@ type Config struct {
 	// Port configurations
 	Ports PortConfig
 
+	// Address configurations
+	Addresses AddressConfig
+
 	// LeaveOnTerm controls if Serf does a graceful leave when receiving
 	// the TERM signal. Defaults false. This can be changed on reload.
 	LeaveOnTerm bool `mapstructure:"leave_on_terminate"`
@@ -627,6 +639,15 @@ func MergeConfig(a, b *Config) *Config {
 	if b.Ports.Server != 0 {
 		result.Ports.Server = b.Ports.Server
 	}
+	if b.Addresses.DNS != "" {
+		result.Addresses.DNS = b.Addresses.DNS
+	}
+	if b.Addresses.HTTP != "" {
+		result.Addresses.HTTP = b.Addresses.HTTP
+	}
+	if b.Addresses.RPC != "" {
+		result.Addresses.RPC = b.Addresses.RPC
+	}
 	if b.UiDir != "" {
 		result.UiDir = b.UiDir
 	}

command/agent/config_test.go

@@ -430,6 +430,23 @@ func TestDecodeConfig(t *testing.T) {
 	if config.StatsdAddr != "127.0.0.1:7251" {
 		t.Fatalf("bad: %#v", config)
 	}
+
+	// Address overrides
+	input = `{"addresses": {"dns": "0.0.0.0", "http": "127.0.0.1", "rpc": "127.0.0.1"}}`
+	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if config.Addresses.DNS != "0.0.0.0" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.Addresses.HTTP != "127.0.0.1" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.Addresses.RPC != "127.0.0.1" {
+		t.Fatalf("bad: %#v", config)
+	}
 }
 
 func TestDecodeConfig_Service(t *testing.T) {
@@ -560,6 +577,11 @@ func TestMergeConfig(t *testing.T) {
 			SerfWan: 5,
 			Server:  6,
 		},
+		Addresses: AddressConfig{
+			DNS:  "127.0.0.1",
+			HTTP: "127.0.0.2",
+			RPC:  "127.0.0.3",
+		},
 		Server:                 true,
 		LeaveOnTerm:            true,
 		SkipLeaveOnInt:         true,