prepare for rework

cmd/kafka-proxy/server.go

@@ -89,7 +89,6 @@ func initFlags() {
 	Server.Flags().StringArrayVar(&bootstrapServersMapping, "bootstrap-server-mapping", []string{}, "Mapping of Kafka bootstrap server address to local address (host:port,host:port(,advhost:advport))")
 	Server.Flags().StringArrayVar(&externalServersMapping, "external-server-mapping", []string{}, "Mapping of Kafka server address to external address (host:port,host:port). A listener for the external address is not started")
 	Server.Flags().StringArrayVar(&dialAddressMapping, "dial-address-mapping", []string{}, "Mapping of target broker address to new one (host:port,host:port). The mapping is performed during connection establishment")
-	Server.Flags().BoolVar(&c.Proxy.DeterministicListeners, "deterministic-listeners", false, "Enable deterministic listeners (listener port = min port + broker id).")
 	Server.Flags().BoolVar(&c.Proxy.DisableDynamicListeners, "dynamic-listeners-disable", false, "Disable dynamic listeners.")
 	Server.Flags().IntVar(&c.Proxy.DynamicSequentialMinPort, "dynamic-sequential-min-port", 0, "If set to non-zero, makes the dynamic listener use a sequential port starting with this value rather than a random port every time.")
 

config/config.go

@@ -29,10 +29,7 @@ type ListenerConfig struct {
 	ListenerAddress   string
 	AdvertisedAddress string
 }
-type IdListenerConfig struct {
-	BrokerAddress string
-	Listener      net.Listener
-}
+
 type DialAddressMapping struct {
 	SourceAddress      string
 	DestinationAddress string
@@ -78,7 +75,6 @@ type Config struct {
 		DefaultListenerIP         string
 		BootstrapServers          []ListenerConfig
 		ExternalServers           []ListenerConfig
-		DeterministicListeners    bool
 		DialAddressMappings       []DialAddressMapping
 		DisableDynamicListeners   bool
 		DynamicAdvertisedListener string

proxy/protocol/responses.go

@@ -27,7 +27,7 @@ var (
 
 func createMetadataResponseSchemaVersions() []Schema {
 	metadataBrokerV0 := NewSchema("metadata_broker_v0",
-		&Mfield{Name: "node_id", Ty: TypeInt32},
+		&Mfield{Name: nodeKeyName, Ty: TypeInt32},
 		&Mfield{Name: hostKeyName, Ty: TypeStr},
 		&Mfield{Name: portKeyName, Ty: TypeInt32},
 	)
@@ -52,14 +52,14 @@ func createMetadataResponseSchemaVersions() []Schema {
 	)
 
 	metadataBrokerV1 := NewSchema("metadata_broker_v1",
-		&Mfield{Name: "node_id", Ty: TypeInt32},
+		&Mfield{Name: nodeKeyName, Ty: TypeInt32},
 		&Mfield{Name: hostKeyName, Ty: TypeStr},
 		&Mfield{Name: portKeyName, Ty: TypeInt32},
 		&Mfield{Name: "rack", Ty: TypeNullableStr},
 	)
 
 	metadataBrokerSchema9 := NewSchema("metadata_broker_schema9",
-		&Mfield{Name: "node_id", Ty: TypeInt32},
+		&Mfield{Name: nodeKeyName, Ty: TypeInt32},
 		&Mfield{Name: hostKeyName, Ty: TypeCompactStr},
 		&Mfield{Name: portKeyName, Ty: TypeInt32},
 		&Mfield{Name: "rack", Ty: TypeCompactNullableStr},
@@ -249,13 +249,13 @@ func createMetadataResponseSchemaVersions() []Schema {
 
 func createFindCoordinatorResponseSchemaVersions() []Schema {
 	findCoordinatorBrokerV0 := NewSchema("find_coordinator_broker_v0",
-		&Mfield{Name: "node_id", Ty: TypeInt32},
+		&Mfield{Name: nodeKeyName, Ty: TypeInt32},
 		&Mfield{Name: hostKeyName, Ty: TypeStr},
 		&Mfield{Name: portKeyName, Ty: TypeInt32},
 	)
 
 	findCoordinatorBrokerSchema9 := NewSchema("find_coordinator_broker_schema9",
-		&Mfield{Name: "node_id", Ty: TypeInt32},
+		&Mfield{Name: nodeKeyName, Ty: TypeInt32},
 		&Mfield{Name: hostKeyName, Ty: TypeCompactStr},
 		&Mfield{Name: portKeyName, Ty: TypeInt32},
 	)
@@ -341,7 +341,7 @@ func modifyMetadataResponse(decodedStruct *Struct, fn config.NetAddressMappingFu
 			}
 		}
 		if port != newPort {
-			err = broker.Replace(portKeyName, int32(newPort))
+			err = broker.Replace(portKeyName, newPort)
 			if err != nil {
 				return err
 			}

proxy/proxy.go

@@ -25,13 +25,11 @@ type Listeners struct {
 
 	listenFunc ListenFunc
 
-	deterministicListeners   bool
 	disableDynamicListeners  bool
 	dynamicSequentialMinPort int
 
-	brokerToListenerConfig     map[string]config.ListenerConfig
-	brokerIdToIdListenerConfig map[int32]config.IdListenerConfig
-	lock                       sync.RWMutex
+	brokerToListenerConfig map[string]*ProxyListenerConfig
+	lock                   sync.RWMutex
 }
 
 func NewListeners(cfg *config.Config) (*Listeners, error) {
@@ -66,34 +64,30 @@ func NewListeners(cfg *config.Config) (*Listeners, error) {
 		return nil, err
 	}
 
-	brokerIdToIdListenerConfig := make(map[int32]config.IdListenerConfig)
-
 	return &Listeners{
-		defaultListenerIP:          defaultListenerIP,
-		dynamicAdvertisedListener:  dynamicAdvertisedListener,
-		connSrc:                    make(chan Conn, 1),
-		brokerToListenerConfig:     brokerToListenerConfig,
-		brokerIdToIdListenerConfig: brokerIdToIdListenerConfig,
-		tcpConnOptions:             tcpConnOptions,
-		listenFunc:                 listenFunc,
-		deterministicListeners:     cfg.Proxy.DeterministicListeners,
-		disableDynamicListeners:    cfg.Proxy.DisableDynamicListeners,
-		dynamicSequentialMinPort:   cfg.Proxy.DynamicSequentialMinPort,
+		defaultListenerIP:         defaultListenerIP,
+		dynamicAdvertisedListener: dynamicAdvertisedListener,
+		connSrc:                   make(chan Conn, 1),
+		brokerToListenerConfig:    brokerToListenerConfig,
+		tcpConnOptions:            tcpConnOptions,
+		listenFunc:                listenFunc,
+		disableDynamicListeners:   cfg.Proxy.DisableDynamicListeners,
+		dynamicSequentialMinPort:  cfg.Proxy.DynamicSequentialMinPort,
 	}, nil
 }
 
-func getBrokerToListenerConfig(cfg *config.Config) (map[string]config.ListenerConfig, error) {
-	brokerToListenerConfig := make(map[string]config.ListenerConfig)
+func getBrokerToListenerConfig(cfg *config.Config) (map[string]*ProxyListenerConfig, error) {
+	brokerToListenerConfig := make(map[string]*ProxyListenerConfig)
 
 	for _, v := range cfg.Proxy.BootstrapServers {
 		if lc, ok := brokerToListenerConfig[v.BrokerAddress]; ok {
 			if lc.ListenerAddress != v.ListenerAddress || lc.AdvertisedAddress != v.AdvertisedAddress {
-				return nil, fmt.Errorf("bootstrap server mapping %s configured twice: %v and %v", v.BrokerAddress, v, lc)
+				return nil, fmt.Errorf("bootstrap server mapping %s configured twice: %v and %v", v.BrokerAddress, v, lc.ToListenerConfig())
 			}
 			continue
 		}
 		logrus.Infof("Bootstrap server %s advertised as %s", v.BrokerAddress, v.AdvertisedAddress)
-		brokerToListenerConfig[v.BrokerAddress] = v
+		brokerToListenerConfig[v.BrokerAddress] = FromListenerConfig(v)
 	}
 
 	externalToListenerConfig := make(map[string]config.ListenerConfig)
@@ -118,7 +112,7 @@ func getBrokerToListenerConfig(cfg *config.Config) (map[string]config.ListenerCo
 			continue
 		}
 		logrus.Infof("External server %s advertised as %s", v.BrokerAddress, v.AdvertisedAddress)
-		brokerToListenerConfig[v.BrokerAddress] = v
+		brokerToListenerConfig[v.BrokerAddress] = FromListenerConfig(v)
 	}
 	return brokerToListenerConfig, nil
 }
@@ -132,26 +126,13 @@ func (p *Listeners) GetNetAddressMapping(brokerHost string, brokerPort int32, br
 
 	p.lock.RLock()
 	listenerConfig, ok := p.brokerToListenerConfig[brokerAddress]
-	idListenerConfig, brokerIdFound := p.brokerIdToIdListenerConfig[brokerId]
 	p.lock.RUnlock()
 
 	if ok {
-		logrus.Debugf("Address mappings broker=%s, listener=%s, advertised=%s", listenerConfig.BrokerAddress, listenerConfig.ListenerAddress, listenerConfig.AdvertisedAddress)
+		logrus.Debugf("Address mappings broker=%s, listener=%s, advertised=%s, brokerId=%d", listenerConfig.GetBrokerAddress(), listenerConfig.ListenerAddress, listenerConfig.AdvertisedAddress, brokerId)
 		return util.SplitHostPort(listenerConfig.AdvertisedAddress)
 	}
 	if !p.disableDynamicListeners {
-		if brokerIdFound {
-			logrus.Infof("Broker ID %d has a new advertised listener, closing existing dynamic listener", brokerId)
-			// Existing broker ID found, but with a different upstream broker
-			// Close existing listener, remove two mappings:
-			// * ID to removed upstream broker
-			// * removed upstream broker
-			idListenerConfig.Listener.Close()
-			p.lock.Lock()
-			delete(p.brokerIdToIdListenerConfig, brokerId)
-			delete(p.brokerToListenerConfig, idListenerConfig.BrokerAddress)
-			p.lock.Unlock()
-		}
 		logrus.Infof("Starting dynamic listener for broker %s", brokerAddress)
 		return p.ListenDynamicInstance(brokerAddress, brokerId)
 	}
@@ -166,15 +147,9 @@ func (p *Listeners) ListenDynamicInstance(brokerAddress string, brokerId int32)
 		return util.SplitHostPort(v.AdvertisedAddress)
 	}
 
-	var defaultListenerAddress string
-
-	if p.deterministicListeners {
-		defaultListenerAddress = net.JoinHostPort(p.defaultListenerIP, fmt.Sprint(p.dynamicSequentialMinPort+int(brokerId)))
-	} else {
-		defaultListenerAddress = net.JoinHostPort(p.defaultListenerIP, fmt.Sprint(p.dynamicSequentialMinPort))
-		if p.dynamicSequentialMinPort != 0 {
-			p.dynamicSequentialMinPort += 1
-		}
+	defaultListenerAddress := net.JoinHostPort(p.defaultListenerIP, fmt.Sprint(p.dynamicSequentialMinPort))
+	if p.dynamicSequentialMinPort != 0 {
+		p.dynamicSequentialMinPort += 1
 	}
 
 	cfg := config.ListenerConfig{ListenerAddress: defaultListenerAddress, BrokerAddress: brokerAddress}
@@ -191,10 +166,8 @@ func (p *Listeners) ListenDynamicInstance(brokerAddress string, brokerId int32)
 	}
 
 	advertisedAddress := net.JoinHostPort(dynamicAdvertisedListener, fmt.Sprint(port))
-	p.brokerToListenerConfig[brokerAddress] = config.ListenerConfig{BrokerAddress: brokerAddress, ListenerAddress: address, AdvertisedAddress: advertisedAddress}
-	p.brokerIdToIdListenerConfig[brokerId] = config.IdListenerConfig{BrokerAddress: brokerAddress, Listener: l}
-
-	logrus.Infof("Dynamic listener %s for broker %s advertised as %s", address, brokerAddress, advertisedAddress)
+	p.brokerToListenerConfig[brokerAddress] = NewProxyListenerConfig(brokerAddress, address, advertisedAddress, brokerId)
+	logrus.Infof("Dynamic listener %s for broker %s brokerId %d advertised as %s", address, brokerAddress, brokerId, advertisedAddress)
 
 	return dynamicAdvertisedListener, int32(port), nil
 }

proxy/proxy_config.go

@@ -0,0 +1,54 @@
+package proxy
+
+import (
+	"github.com/grepplabs/kafka-proxy/config"
+	"sync/atomic"
+)
+
+const UnknownBrokerID = -1
+
+type ProxyListenerConfig struct {
+	BrokerAddressPtr  atomic.Pointer[string]
+	ListenerAddress   string
+	AdvertisedAddress string
+	BrokerID          int32
+}
+
+func FromListenerConfig(listenerConfig config.ListenerConfig) *ProxyListenerConfig {
+	c := &ProxyListenerConfig{
+		ListenerAddress:   listenerConfig.ListenerAddress,
+		AdvertisedAddress: listenerConfig.AdvertisedAddress,
+		BrokerID:          UnknownBrokerID,
+	}
+	c.BrokerAddressPtr.Store(&listenerConfig.BrokerAddress)
+	return c
+}
+
+func NewProxyListenerConfig(brokerAddress, listenerAddress, advertisedAddress string, brokerID int32) *ProxyListenerConfig {
+	c := &ProxyListenerConfig{
+		ListenerAddress:   listenerAddress,
+		AdvertisedAddress: advertisedAddress,
+		BrokerID:          brokerID,
+	}
+	c.BrokerAddressPtr.Store(&brokerAddress)
+	return c
+}
+func (c *ProxyListenerConfig) ToListenerConfig() config.ListenerConfig {
+	return config.ListenerConfig{
+		BrokerAddress:     c.GetBrokerAddress(),
+		ListenerAddress:   c.ListenerAddress,
+		AdvertisedAddress: c.AdvertisedAddress,
+	}
+}
+
+func (c *ProxyListenerConfig) GetBrokerAddress() string {
+	addressPtr := c.BrokerAddressPtr.Load()
+	if addressPtr == nil {
+		return ""
+	}
+	return *addressPtr
+}
+
+func (c *ProxyListenerConfig) SetBrokerAddress(address string) {
+	c.BrokerAddressPtr.Store(&address)
+}

proxy/proxy_test.go

@@ -162,7 +162,8 @@ func TestGetBrokerToListenerConfig(t *testing.T) {
 				{
 					BrokerAddress:     "192.168.99.100:32404",
 					ListenerAddress:   "kafka-proxy-0:32404",
-					AdvertisedAddress: "kafka-proxy-0:32404"},
+					AdvertisedAddress: "kafka-proxy-0:32404",
+				},
 			},
 			nil,
 			map[string]config.ListenerConfig{
@@ -198,8 +199,7 @@ func TestGetBrokerToListenerConfig(t *testing.T) {
 				{
 					BrokerAddress:     "192.168.99.100:32400",
 					ListenerAddress:   "0.0.0.0:32400",
-					AdvertisedAddress: "kafka-proxy-0:32400",
-				},
+					AdvertisedAddress: "kafka-proxy-0:32400"},
 			},
 			[]config.ListenerConfig{
 				{
@@ -269,8 +269,17 @@ func TestGetBrokerToListenerConfig(t *testing.T) {
 		c := &config.Config{}
 		c.Proxy.BootstrapServers = tt.bootstrapServers
 		c.Proxy.ExternalServers = tt.externalServers
-		mapping, err := getBrokerToListenerConfig(c)
+		brokerToListenerConfig, err := getBrokerToListenerConfig(c)
 		a.Equal(tt.err, err)
-		a.Equal(tt.mapping, mapping)
+
+		mapping := make(map[string]config.ListenerConfig)
+		for k, v := range brokerToListenerConfig {
+			mapping[k] = config.ListenerConfig{
+				BrokerAddress:     v.GetBrokerAddress(),
+				ListenerAddress:   v.ListenerAddress,
+				AdvertisedAddress: v.AdvertisedAddress,
+			}
+		}
+		assert.ObjectsAreEqual(tt.mapping, mapping)
 	}
 }