lndclient: use lnd's build package for logging

lndclient/lightning_client.go

@@ -240,7 +240,7 @@ func (s *lightningClient) payInvoice(ctx context.Context, invoice string,
 
 			// Paid successfully.
 			case PaymentResultSuccess:
-				logger.Infof(
+				log.Infof(
 					"Payment %v completed", hash,
 				)
 
@@ -261,7 +261,7 @@ func (s *lightningClient) payInvoice(ctx context.Context, invoice string,
 
 			// Invoice was already paid on a previous run.
 			case PaymentResultAlreadyPaid:
-				logger.Infof(
+				log.Infof(
 					"Payment %v already completed", hash,
 				)
 
@@ -281,7 +281,7 @@ func (s *lightningClient) payInvoice(ctx context.Context, invoice string,
 			// TODO: Improve this when lnd expose more API to
 			// tracking existing payments.
 			case PaymentResultInFlight:
-				logger.Infof(
+				log.Infof(
 					"Payment %v already in flight", hash,
 				)
 
@@ -289,7 +289,7 @@ func (s *lightningClient) payInvoice(ctx context.Context, invoice string,
 
 			// Other errors are transformed into an error struct.
 			default:
-				logger.Warnf(
+				log.Warnf(
 					"Payment %v failed: %v", hash,
 					payResp.PaymentError,
 				)

lndclient/lnd_services.go

@@ -45,13 +45,13 @@ func NewLndServices(lndAddress string, application string,
 	*GrpcLndServices, error) {
 
 	// Setup connection with lnd
-	logger.Infof("Creating lnd connection to %v", lndAddress)
+	log.Infof("Creating lnd connection to %v", lndAddress)
 	conn, err := getClientConn(lndAddress, network, macPath, tlsPath)
 	if err != nil {
 		return nil, err
 	}
 
-	logger.Infof("Connected to lnd")
+	log.Infof("Connected to lnd")
 
 	chainParams, err := swap.ChainParamsFromNetwork(network)
 	if err != nil {
@@ -78,19 +78,19 @@ func NewLndServices(lndAddress string, application string,
 	invoicesClient := newInvoicesClient(conn)
 
 	cleanup := func() {
-		logger.Debugf("Closing lnd connection")
+		log.Debugf("Closing lnd connection")
 		conn.Close()
 
-		logger.Debugf("Wait for client to finish")
+		log.Debugf("Wait for client to finish")
 		lightningClient.WaitForFinished()
 
-		logger.Debugf("Wait for chain notifier to finish")
+		log.Debugf("Wait for chain notifier to finish")
 		notifierClient.WaitForFinished()
 
-		logger.Debugf("Wait for invoices to finish")
+		log.Debugf("Wait for invoices to finish")
 		invoicesClient.WaitForFinished()
 
-		logger.Debugf("Lnd services finished")
+		log.Debugf("Lnd services finished")
 	}
 
 	services := &GrpcLndServices{
@@ -105,7 +105,7 @@ func NewLndServices(lndAddress string, application string,
 		cleanup: cleanup,
 	}
 
-	logger.Infof("Using network %v", network)
+	log.Infof("Using network %v", network)
 
 	return services, nil
 }
@@ -115,7 +115,7 @@ func NewLndServices(lndAddress string, application string,
 func (s *GrpcLndServices) Close() {
 	s.cleanup()
 
-	logger.Debugf("Lnd services finished")
+	log.Debugf("Lnd services finished")
 }
 
 var (

lndclient/log.go

@@ -2,22 +2,28 @@ package lndclient
 
 import (
 	"github.com/btcsuite/btclog"
-	"os"
+	"github.com/lightningnetwork/lnd/build"
 )
 
-// log is a logger that is initialized with no output filters.  This
-// means the package will not perform any logging by default until the caller
-// requests it.
-var (
-	backendLog = btclog.NewBackend(logWriter{})
-	logger     = backendLog.Logger("LNDCLIENT")
-)
+// log is a logger that is initialized with no output filters.  This means the
+// package will not perform any logging by default until the caller requests
+// it.
+var log btclog.Logger
+
+// The default amount of logging is none.
+func init() {
+	UseLogger(build.NewSubLogger("LNDC", nil))
+}
 
-// logWriter implements an io.Writer that outputs to both standard output and
-// the write-end pipe of an initialized log rotator.
-type logWriter struct{}
+// DisableLog disables all library log output.  Logging output is disabled by
+// default until UseLogger is called.
+func DisableLog() {
+	UseLogger(btclog.Disabled)
+}
 
-func (logWriter) Write(p []byte) (n int, err error) {
-	os.Stdout.Write(p)
-	return len(p), nil
+// UseLogger uses a specified Logger to output package logging info.  This
+// should be used in preference to SetLogWriter if the caller is also using
+// btclog.
+func UseLogger(logger btclog.Logger) {
+	log = logger
 }