Implement SRV lookups for filer (#4767)

weed/command/benchmark.go

@@ -127,7 +127,7 @@ func runBenchmark(cmd *Command, args []string) bool {
 		defer pprof.StopCPUProfile()
 	}
 
-	b.masterClient = wdclient.NewMasterClient(b.grpcDialOption, "", "client", "", "", "", pb.ServerAddresses(*b.masters).ToAddressMap())
+	b.masterClient = wdclient.NewMasterClient(b.grpcDialOption, "", "client", "", "", "", *pb.ServerAddresses(*b.masters).ToServiceDiscovery())
 	go b.masterClient.KeepConnectedToMaster()
 	b.masterClient.WaitUntilConnected()
 

weed/command/filer.go

@@ -33,7 +33,7 @@ var (
 )
 
 type FilerOptions struct {
-	masters                 map[string]pb.ServerAddress
+	masters                 *pb.ServerDiscovery
 	mastersString           *string
 	ip                      *string
 	bindIp                  *string
@@ -65,7 +65,7 @@ type FilerOptions struct {
 
 func init() {
 	cmdFiler.Run = runFiler // break init cycle
-	f.mastersString = cmdFiler.Flag.String("master", "localhost:9333", "comma-separated master servers")
+	f.mastersString = cmdFiler.Flag.String("master", "localhost:9333", "comma-separated master servers or a single DNS SRV record of at least 1 master server, prepended with dnssrv+")
 	f.filerGroup = cmdFiler.Flag.String("filerGroup", "", "share metadata with other filers in the same filerGroup")
 	f.collection = cmdFiler.Flag.String("collection", "", "all data will be stored in this default collection")
 	f.ip = cmdFiler.Flag.String("ip", util.DetectedHostAddress(), "filer server http listen ip address")
@@ -208,7 +208,7 @@ func runFiler(cmd *Command, args []string) bool {
 		}(startDelay)
 	}
 
-	f.masters = pb.ServerAddresses(*f.mastersString).ToAddressMap()
+	f.masters = pb.ServerAddresses(*f.mastersString).ToServiceDiscovery()
 
 	f.startFiler()
 

weed/command/server.go

@@ -203,7 +203,7 @@ func runServer(cmd *Command, args []string) bool {
 	// ip address
 	masterOptions.ip = serverIp
 	masterOptions.ipBind = serverBindIp
-	filerOptions.masters = pb.ServerAddresses(*masterOptions.peers).ToAddressMap()
+	filerOptions.masters = pb.ServerAddresses(*masterOptions.peers).ToServiceDiscovery()
 	filerOptions.ip = serverIp
 	filerOptions.bindIp = serverBindIp
 	s3Options.bindIp = serverBindIp
@@ -216,7 +216,7 @@ func runServer(cmd *Command, args []string) bool {
 	serverOptions.v.dataCenter = serverDataCenter
 	serverOptions.v.rack = serverRack
 	mqBrokerOptions.ip = serverIp
-	mqBrokerOptions.masters = filerOptions.masters
+	mqBrokerOptions.masters = filerOptions.masters.GetInstancesAsMap()
 	mqBrokerOptions.filerGroup = filerOptions.filerGroup
 
 	// serverOptions.v.pulseSeconds = pulseSeconds

weed/filer/filer.go

@@ -52,8 +52,7 @@ type Filer struct {
 	Dlm                 *lock_manager.DistributedLockManager
 }
 
-func NewFiler(masters map[string]pb.ServerAddress, grpcDialOption grpc.DialOption, filerHost pb.ServerAddress,
+func NewFiler(masters pb.ServerDiscovery, grpcDialOption grpc.DialOption, filerHost pb.ServerAddress, filerGroup string, collection string, replication string, dataCenter string, notifyFn func()) *Filer {
-	filerGroup string, collection string, replication string, dataCenter string, notifyFn func()) *Filer {
 	f := &Filer{
 		MasterClient:        wdclient.NewMasterClient(grpcDialOption, filerGroup, cluster.FilerType, filerHost, dataCenter, "", masters),
 		fileIdDeletionQueue: util.NewUnboundedQueue(),

weed/filer/leveldb/leveldb_store_test.go

@@ -3,6 +3,7 @@ package leveldb
 import (
 	"context"
 	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"os"
 	"testing"
 	"time"
@@ -12,7 +13,7 @@ import (
 )
 
 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := t.TempDir()
 	store := &LevelDBStore{}
 	store.initialize(dir)
@@ -65,7 +66,7 @@ func TestCreateAndFind(t *testing.T) {
 }
 
 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := t.TempDir()
 	store := &LevelDBStore{}
 	store.initialize(dir)
@@ -87,7 +88,7 @@ func TestEmptyRoot(t *testing.T) {
 }
 
 func BenchmarkInsertEntry(b *testing.B) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := b.TempDir()
 	store := &LevelDBStore{}
 	store.initialize(dir)

weed/filer/leveldb2/leveldb2_store_test.go

@@ -2,6 +2,7 @@ package leveldb
 
 import (
 	"context"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"testing"
 
 	"github.com/seaweedfs/seaweedfs/weed/filer"
@@ -9,7 +10,7 @@ import (
 )
 
 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := t.TempDir()
 	store := &LevelDB2Store{}
 	store.initialize(dir, 2)
@@ -62,7 +63,7 @@ func TestCreateAndFind(t *testing.T) {
 }
 
 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := t.TempDir()
 	store := &LevelDB2Store{}
 	store.initialize(dir, 2)

weed/filer/leveldb3/leveldb3_store_test.go

@@ -2,6 +2,7 @@ package leveldb
 
 import (
 	"context"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"testing"
 
 	"github.com/seaweedfs/seaweedfs/weed/filer"
@@ -9,7 +10,7 @@ import (
 )
 
 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := t.TempDir()
 	store := &LevelDB3Store{}
 	store.initialize(dir)
@@ -62,7 +63,7 @@ func TestCreateAndFind(t *testing.T) {
 }
 
 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", nil)
 	dir := t.TempDir()
 	store := &LevelDB3Store{}
 	store.initialize(dir)

weed/filer/rocksdb/rocksdb_store_test.go

@@ -15,7 +15,7 @@ import (
 )
 
 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", 0, "", "", "", nil)
 	dir := t.TempDir()
 	store := &RocksDBStore{}
 	store.initialize(dir)
@@ -68,7 +68,7 @@ func TestCreateAndFind(t *testing.T) {
 }
 
 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", 0, "", "", "", nil)
 	dir := t.TempDir()
 	store := &RocksDBStore{}
 	store.initialize(dir)
@@ -90,7 +90,7 @@ func TestEmptyRoot(t *testing.T) {
 }
 
 func BenchmarkInsertEntry(b *testing.B) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", 0, "", "", "", nil)
 	dir := b.TempDir()
 	store := &RocksDBStore{}
 	store.initialize(dir)

weed/iamapi/iamapi_server.go

@@ -50,7 +50,7 @@ var s3ApiConfigure IamS3ApiConfig
 func NewIamApiServer(router *mux.Router, option *IamServerOption) (iamApiServer *IamApiServer, err error) {
 	s3ApiConfigure = IamS3ApiConfigure{
 		option:       option,
-		masterClient: wdclient.NewMasterClient(option.GrpcDialOption, "", "iam", "", "", "", option.Masters),
+		masterClient: wdclient.NewMasterClient(option.GrpcDialOption, "", "iam", "", "", "", *pb.NewServiceDiscoveryFromMap(option.Masters)),
 	}
 	s3Option := s3api.S3ApiServerOption{Filer: option.Filer}
 	iamApiServer = &IamApiServer{

weed/mq/broker/broker_server.go

@@ -41,7 +41,7 @@ func NewMessageBroker(option *MessageQueueBrokerOption, grpcDialOption grpc.Dial
 	mqBroker = &MessageQueueBroker{
 		option:            option,
 		grpcDialOption:    grpcDialOption,
-		MasterClient:      wdclient.NewMasterClient(grpcDialOption, option.FilerGroup, cluster.BrokerType, pb.NewServerAddress(option.Ip, option.Port, 0), option.DataCenter, option.Rack, option.Masters),
+		MasterClient:   wdclient.NewMasterClient(grpcDialOption, option.FilerGroup, cluster.BrokerType, pb.NewServerAddress(option.Ip, option.Port, 0), option.DataCenter, option.Rack, *pb.NewServiceDiscoveryFromMap(option.Masters)),
 		filers:            make(map[pb.ServerAddress]struct{}),
 		localTopicManager: topic.NewLocalTopicManager(),
 	}

weed/pb/server_address.go

@@ -11,6 +11,7 @@ import (
 
 type ServerAddress string
 type ServerAddresses string
+type ServerSrvAddress string
 
 func NewServerAddress(host string, port int, grpcPort int) ServerAddress {
 	if grpcPort == 0 || grpcPort == port+10000 {
@@ -76,6 +77,42 @@ func (sa ServerAddress) ToGrpcAddress() string {
 	return ServerToGrpcAddress(string(sa))
 }
 
+// LookUp may return an error for some records along with successful lookups - make sure you do not
+// discard `addresses` even if `err == nil`
+func (r ServerSrvAddress) LookUp() (addresses []ServerAddress, err error) {
+	_, records, lookupErr := net.LookupSRV("", "", string(r))
+	if lookupErr != nil {
+		err = fmt.Errorf("lookup SRV address %s: %v", r, lookupErr)
+	}
+	for _, srv := range records {
+		address := fmt.Sprintf("%s:%d", srv.Target, srv.Port)
+		addresses = append(addresses, ServerAddress(address))
+	}
+	return
+}
+
+// ToServiceDiscovery expects one of: a comma-separated list of ip:port, like
+//
+//	10.0.0.1:9999,10.0.0.2:24:9999
+//
+// OR an SRV Record prepended with 'dnssrv+', like:
+//
+//	dnssrv+_grpc._tcp.master.consul
+//	dnssrv+_grpc._tcp.headless.default.svc.cluster.local
+//	dnssrv+seaweed-master.master.consul
+func (sa ServerAddresses) ToServiceDiscovery() (sd *ServerDiscovery) {
+	sd = &ServerDiscovery{}
+	prefix := "dnssrv+"
+	if strings.HasPrefix(string(sa), prefix) {
+		trimmed := strings.TrimPrefix(string(sa), prefix)
+		srv := ServerSrvAddress(trimmed)
+		sd.srvRecord = &srv
+	} else {
+		sd.list = sa.ToAddresses()
+	}
+	return
+}
+
 func (sa ServerAddresses) ToAddresses() (addresses []ServerAddress) {
 	parts := strings.Split(string(sa), ",")
 	for _, address := range parts {

weed/pb/server_address_test.go

@@ -0,0 +1,36 @@
+package pb
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestServerAddresses_ToAddressMapOrSrv_shouldRemovePrefix(t *testing.T) {
+	str := ServerAddresses("dnssrv+hello.srv.consul")
+
+	d := str.ToServiceDiscovery()
+
+	expected := ServerSrvAddress("hello.srv.consul")
+	if *d.srvRecord != expected {
+		t.Fatalf(`ServerAddresses("dnssrv+hello.srv.consul") = %s, expected %s`, *d.srvRecord, expected)
+	}
+}
+
+func TestServerAddresses_ToAddressMapOrSrv_shouldHandleIPPortList(t *testing.T) {
+	str := ServerAddresses("10.0.0.1:23,10.0.0.2:24")
+
+	d := str.ToServiceDiscovery()
+
+	if d.srvRecord != nil {
+		t.Fatalf(`ServerAddresses("dnssrv+hello.srv.consul") = %s, expected nil`, *d.srvRecord)
+	}
+
+	expected := []ServerAddress{
+		ServerAddress("10.0.0.1:23"),
+		ServerAddress("10.0.0.2:24"),
+	}
+
+	if !reflect.DeepEqual(d.list, expected) {
+		t.Fatalf(`Expected %q, got %q`, expected, d.list)
+	}
+}

weed/pb/server_discovery.go

@@ -0,0 +1,62 @@
+package pb
+
+import (
+	"github.com/seaweedfs/seaweedfs/weed/glog"
+	"reflect"
+)
+
+// ServerDiscovery encodes a way to find at least 1 instance of a service,
+// and provides utility functions to refresh the instance list
+type ServerDiscovery struct {
+	list      []ServerAddress
+	srvRecord *ServerSrvAddress
+}
+
+func NewServiceDiscoveryFromMap(m map[string]ServerAddress) (sd *ServerDiscovery) {
+	sd = &ServerDiscovery{}
+	for _, s := range m {
+		sd.list = append(sd.list, s)
+	}
+	return sd
+}
+
+// RefreshBySrvIfAvailable performs a DNS SRV lookup and updates list with the results
+// of the lookup
+func (sd *ServerDiscovery) RefreshBySrvIfAvailable() {
+	if sd.srvRecord == nil {
+		return
+	}
+	newList, err := sd.srvRecord.LookUp()
+	if err != nil {
+		glog.V(0).Infof("failed to lookup SRV for %s: %v", *sd.srvRecord, err)
+	}
+	if newList == nil || len(newList) == 0 {
+		glog.V(0).Infof("looked up SRV for %s, but found no well-formed names", *sd.srvRecord)
+		return
+	}
+	if !reflect.DeepEqual(sd.list, newList) {
+		sd.list = newList
+	}
+}
+
+// GetInstances returns a copy of the latest known list of addresses
+// call RefreshBySrvIfAvailable prior to this in order to get a more up-to-date view
+func (sd *ServerDiscovery) GetInstances() (addresses []ServerAddress) {
+	for _, a := range sd.list {
+		addresses = append(addresses, a)
+	}
+	return addresses
+}
+func (sd *ServerDiscovery) GetInstancesAsStrings() (addresses []string) {
+	for _, i := range sd.list {
+		addresses = append(addresses, string(i))
+	}
+	return addresses
+}
+func (sd *ServerDiscovery) GetInstancesAsMap() (addresses map[string]ServerAddress) {
+	addresses = make(map[string]ServerAddress)
+	for _, i := range sd.list {
+		addresses[string(i)] = i
+	}
+	return addresses
+}

weed/server/filer_grpc_server_admin.go

@@ -87,7 +87,7 @@ func (fs *FilerServer) GetFilerConfiguration(ctx context.Context, req *filer_pb.
 	clusterId, _ := fs.filer.Store.KvGet(context.Background(), []byte("clusterId"))
 
 	t := &filer_pb.GetFilerConfigurationResponse{
-		Masters:            pb.ToAddressStringsFromMap(fs.option.Masters),
+		Masters:            fs.option.Masters.GetInstancesAsStrings(),
 		Collection:         fs.option.Collection,
 		Replication:        fs.option.DefaultReplication,
 		MaxMb:              uint32(fs.option.MaxMB),

weed/server/filer_server.go

@@ -50,7 +50,7 @@ import (
 )
 
 type FilerOption struct {
-	Masters               map[string]pb.ServerAddress
+	Masters               *pb.ServerDiscovery
 	FilerGroup            string
 	Collection            string
 	DefaultReplication    string
@@ -118,11 +118,12 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 	}
 	fs.listenersCond = sync.NewCond(&fs.listenersLock)
 
-	if len(option.Masters) == 0 {
+	option.Masters.RefreshBySrvIfAvailable()
+	if len(option.Masters.GetInstances()) == 0 {
 		glog.Fatal("master list is required!")
 	}
 
-	fs.filer = filer.NewFiler(option.Masters, fs.grpcDialOption, option.Host, option.FilerGroup, option.Collection, option.DefaultReplication, option.DataCenter, func() {
+	fs.filer = filer.NewFiler(*option.Masters, fs.grpcDialOption, option.Host, option.FilerGroup, option.Collection, option.DefaultReplication, option.DataCenter, func() {
 		fs.listenersCond.Broadcast()
 	})
 	fs.filer.Cipher = option.Cipher
@@ -195,7 +196,8 @@ func (fs *FilerServer) checkWithMaster() {
 
 	isConnected := false
 	for !isConnected {
-		for _, master := range fs.option.Masters {
+		fs.option.Masters.RefreshBySrvIfAvailable()
+		for _, master := range fs.option.Masters.GetInstances() {
 			readErr := operation.WithMasterServerClient(false, master, fs.grpcDialOption, func(masterClient master_pb.SeaweedClient) error {
 				resp, err := masterClient.GetMasterConfiguration(context.Background(), &master_pb.GetMasterConfigurationRequest{})
 				if err != nil {

weed/server/master_server.go

@@ -110,7 +110,7 @@ func NewMasterServer(r *mux.Router, option *MasterOption, peers map[string]pb.Se
 		vgCh:            make(chan *topology.VolumeGrowRequest, 1<<6),
 		clientChans:     make(map[string]chan *master_pb.KeepConnectedResponse),
 		grpcDialOption:  grpcDialOption,
-		MasterClient:    wdclient.NewMasterClient(grpcDialOption, "", cluster.MasterType, option.Master, "", "", peers),
+		MasterClient:    wdclient.NewMasterClient(grpcDialOption, "", cluster.MasterType, option.Master, "", "", *pb.NewServiceDiscoveryFromMap(peers)),
 		adminLocks:      NewAdminLocks(),
 		Cluster:         cluster.NewCluster(),
 	}

weed/shell/commands.go

@@ -51,7 +51,7 @@ var (
 func NewCommandEnv(options *ShellOptions) *CommandEnv {
 	ce := &CommandEnv{
 		env:          make(map[string]string),
-		MasterClient: wdclient.NewMasterClient(options.GrpcDialOption, *options.FilerGroup, pb.AdminShellClient, "", "", "", pb.ServerAddresses(*options.Masters).ToAddressMap()),
+		MasterClient: wdclient.NewMasterClient(options.GrpcDialOption, *options.FilerGroup, pb.AdminShellClient, "", "", "", *pb.ServerAddresses(*options.Masters).ToServiceDiscovery()),
 		option:       options,
 	}
 	ce.locker = exclusive_locks.NewExclusiveLocker(ce.MasterClient, "shell")

weed/stats/metrics.go

@@ -299,7 +299,6 @@ func JoinHostPort(host string, port int) string {
 	return net.JoinHostPort(host, portStr)
 }
 
-
 func StartMetricsServer(ip string, port int) {
 	if port == 0 {
 		return

weed/wdclient/masterclient.go

@@ -24,8 +24,8 @@ type MasterClient struct {
 	rack              string
 	currentMaster     pb.ServerAddress
 	currentMasterLock sync.RWMutex
-	masters           map[string]pb.ServerAddress
+	masters           pb.ServerDiscovery
-	grpcDialOption    grpc.DialOption
+	grpcDialOption grpc.DialOption
 
 	*vidMap
 	vidMapCacheSize  int
@@ -33,7 +33,7 @@ type MasterClient struct {
 	OnPeerUpdateLock sync.RWMutex
 }
 
-func NewMasterClient(grpcDialOption grpc.DialOption, filerGroup string, clientType string, clientHost pb.ServerAddress, clientDataCenter string, rack string, masters map[string]pb.ServerAddress) *MasterClient {
+func NewMasterClient(grpcDialOption grpc.DialOption, filerGroup string, clientType string, clientHost pb.ServerAddress, clientDataCenter string, rack string, masters pb.ServerDiscovery) *MasterClient {
 	return &MasterClient{
 		FilerGroup:      filerGroup,
 		clientType:      clientType,
@@ -108,9 +108,9 @@ func (mc *MasterClient) GetMaster() pb.ServerAddress {
 	return mc.getCurrentMaster()
 }
 
-func (mc *MasterClient) GetMasters() map[string]pb.ServerAddress {
+func (mc *MasterClient) GetMasters() []pb.ServerAddress {
 	mc.WaitUntilConnected()
-	return mc.masters
+	return mc.masters.GetInstances()
 }
 
 func (mc *MasterClient) WaitUntilConnected() {
@@ -132,7 +132,7 @@ func (mc *MasterClient) KeepConnectedToMaster() {
 }
 
 func (mc *MasterClient) FindLeaderFromOtherPeers(myMasterAddress pb.ServerAddress) (leader string) {
-	for _, master := range mc.masters {
+	for _, master := range mc.masters.GetInstances() {
 		if master == myMasterAddress {
 			continue
 		}
@@ -159,7 +159,8 @@ func (mc *MasterClient) FindLeaderFromOtherPeers(myMasterAddress pb.ServerAddres
 
 func (mc *MasterClient) tryAllMasters() {
 	var nextHintedLeader pb.ServerAddress
-	for _, master := range mc.masters {
+	mc.masters.RefreshBySrvIfAvailable()
+	for _, master := range mc.masters.GetInstances() {
 		nextHintedLeader = mc.tryConnectToMaster(master)
 		for nextHintedLeader != "" {
 			nextHintedLeader = mc.tryConnectToMaster(nextHintedLeader)

weed/wdclient/vid_map_test.go

@@ -3,6 +3,7 @@ package wdclient
 import (
 	"context"
 	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"google.golang.org/grpc"
 	"strconv"
 	"sync"
@@ -65,7 +66,7 @@ func TestLocationIndex(t *testing.T) {
 }
 
 func TestLookupFileId(t *testing.T) {
-	mc := NewMasterClient(grpc.EmptyDialOption{}, "", "", "", "", "", nil)
+	mc := NewMasterClient(grpc.EmptyDialOption{}, "", "", "", "", "", pb.ServerDiscovery{})
 	length := 5
 
 	//Construct a cache linked list of length 5
@@ -135,7 +136,7 @@ func TestLookupFileId(t *testing.T) {
 }
 
 func TestConcurrentGetLocations(t *testing.T) {
-	mc := NewMasterClient(grpc.EmptyDialOption{}, "", "", "", "", "", nil)
+	mc := NewMasterClient(grpc.EmptyDialOption{}, "", "", "", "", "", pb.ServerDiscovery{})
 	location := Location{Url: "TestDataRacing"}
 	mc.addLocation(1, location)