diff --git a/lnd.go b/lnd.go index ccce8f9f..ee9cd268 100644 --- a/lnd.go +++ b/lnd.go @@ -59,16 +59,25 @@ var ( networkDir string ) +// ListnerWithSignal is a net.Listner that has an additional Ready channel that +// will be closed when a server starts listening. +type ListenerWithSignal struct { + net.Listener + + // Ready will be closed by the server listening on Listener. + Ready chan struct{} +} + // ListenerCfg is a wrapper around custom listeners that can be passed to lnd // when calling its main method. type ListenerCfg struct { // WalletUnlocker can be set to the listener to use for the wallet // unlocker. If nil a regular network listener will be created. - WalletUnlocker net.Listener + WalletUnlocker *ListenerWithSignal // RPCListener can be set to the listener to use for the RPC server. If // nil a regular network listener will be created. - RPCListener net.Listener + RPCListener *ListenerWithSignal } // rpcListeners is a function type used for closures that fetches a set of RPC @@ -76,7 +85,8 @@ type ListenerCfg struct { // with these listeners. If no custom listeners are present, this should return // normal listeners from the RPC endpoints defined in the config, and server // options specifying TLS. -type rpcListeners func() ([]net.Listener, func(), []grpc.ServerOption, error) +type rpcListeners func() ([]*ListenerWithSignal, func(), []grpc.ServerOption, + error) // Main is the true entry point for lnd. This function is required since defers // created in the top-level scope of a main method aren't executed if os.Exit() @@ -235,10 +245,10 @@ func Main(lisCfg ListenerCfg) error { // getListeners is a closure that creates listeners from the // RPCListeners defined in the config. It also returns a cleanup // closure and the server options to use for the GRPC server. - getListeners := func() ([]net.Listener, func(), []grpc.ServerOption, - error) { + getListeners := func() ([]*ListenerWithSignal, func(), + []grpc.ServerOption, error) { - var grpcListeners []net.Listener + var grpcListeners []*ListenerWithSignal for _, grpcEndpoint := range cfg.RPCListeners { // Start a gRPC server listening for HTTP/2 // connections. @@ -248,7 +258,11 @@ func Main(lisCfg ListenerCfg) error { grpcEndpoint) return nil, nil, nil, err } - grpcListeners = append(grpcListeners, lis) + grpcListeners = append( + grpcListeners, &ListenerWithSignal{ + Listener: lis, + Ready: make(chan struct{}), + }) } cleanup := func() { @@ -262,7 +276,7 @@ func Main(lisCfg ListenerCfg) error { // walletUnlockerListeners is a closure we'll hand to the wallet // unlocker, that will be called when it needs listeners for its GPRC // server. - walletUnlockerListeners := func() ([]net.Listener, func(), + walletUnlockerListeners := func() ([]*ListenerWithSignal, func(), []grpc.ServerOption, error) { // If we have chosen to start with a dedicated listener for the @@ -271,8 +285,8 @@ func Main(lisCfg ListenerCfg) error { // TODO(halseth): any point in adding TLS support for custom // listeners? if lisCfg.WalletUnlocker != nil { - return []net.Listener{lisCfg.WalletUnlocker}, func() {}, - []grpc.ServerOption{}, nil + return []*ListenerWithSignal{lisCfg.WalletUnlocker}, + func() {}, []grpc.ServerOption{}, nil } // Otherwise we'll return the regular listeners. @@ -501,8 +515,8 @@ func Main(lisCfg ListenerCfg) error { // rpcListeners is a closure we'll hand to the rpc server, that will be // called when it needs listeners for its GPRC server. - rpcListeners := func() ([]net.Listener, func(), []grpc.ServerOption, - error) { + rpcListeners := func() ([]*ListenerWithSignal, func(), + []grpc.ServerOption, error) { // If we have chosen to start with a dedicated listener for the // rpc server, we return it directly, and empty server options @@ -510,8 +524,8 @@ func Main(lisCfg ListenerCfg) error { // TODO(halseth): any point in adding TLS support for custom // listeners? if lisCfg.RPCListener != nil { - return []net.Listener{lisCfg.RPCListener}, func() {}, - []grpc.ServerOption{}, nil + return []*ListenerWithSignal{lisCfg.RPCListener}, + func() {}, []grpc.ServerOption{}, nil } // Otherwise we'll return the regular listeners. @@ -841,9 +855,13 @@ func waitForWalletPassword(restEndpoints []net.Addr, for _, lis := range listeners { wg.Add(1) - go func(lis net.Listener) { + go func(lis *ListenerWithSignal) { rpcsLog.Infof("password RPC server listening on %s", lis.Addr()) + + // Close the ready chan to indicate we are listening. + close(lis.Ready) + wg.Done() grpcServer.Serve(lis) }(lis) diff --git a/rpcserver.go b/rpcserver.go index 63d9d8f5..c9b1eee4 100644 --- a/rpcserver.go +++ b/rpcserver.go @@ -9,7 +9,6 @@ import ( "fmt" "io" "math" - "net" "net/http" "sort" "strings" @@ -456,7 +455,7 @@ type rpcServer struct { // listeners is a list of listeners to use when starting the grpc // server. We make it configurable such that the grpc server can listen // on custom interfaces. - listeners []net.Listener + listeners []*ListenerWithSignal // listenerCleanUp are a set of closures functions that will allow this // main RPC server to clean up all the listening socket created for the @@ -706,8 +705,11 @@ func (r *rpcServer) Start() error { // With all the sub-servers started, we'll spin up the listeners for // the main RPC server itself. for _, lis := range r.listeners { - go func(lis net.Listener) { + go func(lis *ListenerWithSignal) { rpcsLog.Infof("RPC server listening on %s", lis.Addr()) + + // Close the ready chan to indicate we are listening. + close(lis.Ready) r.grpcServer.Serve(lis) }(lis) }