multi: add persistent logger

auth/log.go

@@ -0,0 +1,29 @@
+package auth
+
+import (
+	"github.com/btcsuite/btclog"
+	"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 log btclog.Logger
+
+// The default amount of logging is none.
+func init() {
+	UseLogger(build.NewSubLogger("AUTH", nil))
+}
+
+// DisableLog disables all library log output.  Logging output is disabled
+// by default until UseLogger is called.
+func DisableLog() {
+	UseLogger(btclog.Disabled)
+}
+
+// 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
+}

config.go

@@ -11,6 +11,10 @@ var (
 	defaultConfigFilename  = "kirin.yaml"
 	defaultTLSKeyFilename  = "tls.key"
 	defaultTLSCertFilename = "tls.cert"
+	defaultLogLevel        = "info"
+	defaultLogFilename     = "kirin.log"
+	defaultMaxLogFiles     = 3
+	defaultMaxLogFileSize  = 10
 )
 
 type config struct {
@@ -23,4 +27,8 @@ type config struct {
 	// Services is a list of JSON objects in string format, which specify
 	// each backend service to Kirin.
 	Services []*proxy.Service `long:"service" description:"Configurations for each Kirin backend service."`
+
+	// DebugLevel is a string defining the log level for the service either
+	// for all subsystems the same or individual level by subsystem.
+	DebugLevel string `long:"debuglevel" description:"Debug level for the Kirin application and its subsystems."`
 }

go.mod

@@ -3,6 +3,7 @@ module github.com/lightninglabs/kirin
 go 1.13
 
 require (
+	github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f
 	github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d
 	github.com/lightninglabs/loop v0.2.3-alpha
 	github.com/lightningnetwork/lnd v0.8.0-beta-rc3.0.20191029004703-c069bdd4c7c1

go.sum

@@ -28,7 +28,6 @@ github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f h1:bAs4lUbRJpnnkd9
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
 github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d h1:yJzD/yFppdVCf6ApMkVy8cUxV0XrxdP9rVf6D87/Mng=
 github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
-github.com/btcsuite/btcwallet v0.0.0-20190911065739-d5cdeb4b91b0 h1:S9+cnZ7N4EvkkOBQ3lUy4p7+XjW4GS81R4QjwuT06Cw=
 github.com/btcsuite/btcwallet v0.0.0-20190911065739-d5cdeb4b91b0/go.mod h1:ntLqUbZ12G8FmPX1nJj7W83WiAFOLRGiuarH4zDYdlI=
 github.com/btcsuite/btcwallet v0.10.0 h1:fFZncfYJ7VByePTGttzJc3qfCyDzU95ucZYk0M912lU=
 github.com/btcsuite/btcwallet v0.10.0/go.mod h1:4TqBEuceheGNdeLNrelliLHJzmXauMM2vtWfuy1pFiM=
@@ -146,7 +145,6 @@ github.com/lightninglabs/neutrino v0.10.0 h1:yWVy2cOCCXbKFdpYCE9vD1fWRJDd9FtGXhU
 github.com/lightninglabs/neutrino v0.10.0/go.mod h1:C3KhCMk1Mcx3j8v0qRVWM1Ow6rIJSvSPnUAq00ZNAfk=
 github.com/lightningnetwork/lightning-onion v0.0.0-20190909101754-850081b08b6a h1:GoWPN4i4jTKRxhVNh9a2vvBBO1Y2seiJB+SopUYoKyo=
 github.com/lightningnetwork/lightning-onion v0.0.0-20190909101754-850081b08b6a/go.mod h1:rigfi6Af/KqsF7Za0hOgcyq2PNH4AN70AaMRxcJkff4=
-github.com/lightningnetwork/lnd v0.7.1-beta-rc2.0.20190914085956-35027e52fc22 h1:PWCIRUyow3Od4TMukVHL5jmNhjUPKhw6OVVruYCCUQ0=
 github.com/lightningnetwork/lnd v0.7.1-beta-rc2.0.20190914085956-35027e52fc22/go.mod h1:VaY0b5o38keUN3Ga6GVb/Mgta4B/CcCXwNvPAvhbv/A=
 github.com/lightningnetwork/lnd v0.8.0-beta-rc3.0.20191029004703-c069bdd4c7c1 h1:HZqM9i0znXr+FZAO1Km7bpnlUFt+/qbfFDkfOEDT6Gc=
 github.com/lightningnetwork/lnd v0.8.0-beta-rc3.0.20191029004703-c069bdd4c7c1/go.mod h1:nq06y2BDv7vwWeMmwgB7P3pT7/Uj7sGf5FzHISVD6t4=

kirin.go

@@ -6,15 +6,13 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
-	
+
 	"github.com/lightninglabs/kirin/auth"
 	"github.com/lightninglabs/kirin/proxy"
+	"github.com/lightningnetwork/lnd/build"
 	"gopkg.in/yaml.v2"
 )
 
-/**
- */
-
 // Main is the true entrypoint of Kirin.
 func Main() {
 	// TODO: Prevent from running twice.
@@ -25,22 +23,21 @@ func Main() {
 	}
 }
 
+// start sets up the proxy server and runs it. This function blocks until a
+// shutdown signal is received.
 func start() error {
+	// First, parse configuration file and set up logging.
 	configFile := filepath.Join(kirinDataDir, defaultConfigFilename)
-	var cfg config
-	b, err := ioutil.ReadFile(configFile)
+	cfg, err := getConfig(configFile)
 	if err != nil {
-		return err
-	}
-
-	err = yaml.Unmarshal(b, &cfg)
-	if err != nil {
-		return err
-	}
-	if cfg.ListenAddr == "" {
-		return fmt.Errorf("missing listen address for server")
+		return fmt.Errorf("unable to parse config file: %v", err)
+	}
+	err = setupLogging(cfg)
+	if err != nil {
+		return fmt.Errorf("unable to set up logging: %v", err)
 	}
 
+	// Create the auxiliary services the proxy needs to work.
 	authenticator, err := auth.NewLndAuthenticator(cfg.Authenticator)
 	if err != nil {
 		return err
@@ -50,13 +47,68 @@ func start() error {
 		return err
 	}
 
-	// Start the reverse proxy.
+	// Finally start the reverse proxy.
 	server := &http.Server{
 		Addr:    cfg.ListenAddr,
 		Handler: http.HandlerFunc(servicesProxy.ServeHTTP),
 	}
-
 	tlsKeyFile := filepath.Join(kirinDataDir, defaultTLSKeyFilename)
 	tlsCertFile := filepath.Join(kirinDataDir, defaultTLSCertFilename)
+
+	// The ListenAndServeTLS below will block until shut down or an error
+	// occurs. So we can just defer a cleanup function here that will close
+	// everything on shutdown.
+	defer cleanup(server)
 	return server.ListenAndServeTLS(tlsCertFile, tlsKeyFile)
 }
+
+// getConfig loads and parses the configuration file then checks it for valid
+// content.
+func getConfig(configFile string) (*config, error) {
+	cfg := &config{}
+	b, err := ioutil.ReadFile(configFile)
+	if err != nil {
+		return nil, err
+	}
+	err = yaml.Unmarshal(b, cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	// Then check the configuration that we got from the config file, all
+	// required values need to be set at this point.
+	if cfg.ListenAddr == "" {
+		return nil, fmt.Errorf("missing listen address for server")
+	}
+	return cfg, nil
+}
+
+// setupLogging parses the debug level and initializes the log file rotator.
+func setupLogging(cfg *config) error {
+	if cfg.DebugLevel == "" {
+		cfg.DebugLevel = defaultLogLevel
+	}
+
+	// Now initialize the logger and set the log level.
+	logFile := filepath.Join(kirinDataDir, defaultLogFilename)
+	err := logWriter.InitLogRotator(
+		logFile, defaultMaxLogFileSize, defaultMaxLogFiles,
+	)
+	if err != nil {
+		return err
+	}
+	return build.ParseAndSetDebugLevels(cfg.DebugLevel, logWriter)
+}
+
+// cleanup closes the given server and shuts down the log rotator.
+func cleanup(server *http.Server) {
+	err := server.Close()
+	if err != nil {
+		log.Errorf("Error closing server: %v", err)
+	}
+	log.Info("Shutdown complete")
+	err = logWriter.Close()
+	if err != nil {
+		log.Errorf("Could not close log rotator: %v", err)
+	}
+}

log.go

@@ -0,0 +1,38 @@
+package kirin
+
+import (
+	"github.com/btcsuite/btclog"
+	"github.com/lightninglabs/kirin/auth"
+	"github.com/lightninglabs/kirin/proxy"
+	"github.com/lightningnetwork/lnd/build"
+)
+
+var (
+	logWriter = build.NewRotatingLogWriter()
+
+	log = build.NewSubLogger("MAIN", logWriter.GenSubLogger)
+)
+
+func init() {
+	setSubLogger("MAIN", log, nil)
+	addSubLogger("AUTH", auth.UseLogger)
+	addSubLogger("PRXY", proxy.UseLogger)
+}
+
+// addSubLogger is a helper method to conveniently create and register the
+// logger of a sub system.
+func addSubLogger(subsystem string, useLogger func(btclog.Logger)) {
+	logger := build.NewSubLogger(subsystem, logWriter.GenSubLogger)
+	setSubLogger(subsystem, logger, useLogger)
+}
+
+// setSubLogger is a helper method to conveniently register the logger of a sub
+// system.
+func setSubLogger(subsystem string, logger btclog.Logger,
+	useLogger func(btclog.Logger)) {
+
+	logWriter.RegisterSubLogger(subsystem, logger)
+	if useLogger != nil {
+		useLogger(logger)
+	}
+}

proxy/log.go

@@ -0,0 +1,29 @@
+package proxy
+
+import (
+	"github.com/btcsuite/btclog"
+	"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 log btclog.Logger
+
+// The default amount of logging is none.
+func init() {
+	UseLogger(build.NewSubLogger("PRXY", nil))
+}
+
+// DisableLog disables all library log output.  Logging output is disabled
+// by default until UseLogger is called.
+func DisableLog() {
+	UseLogger(btclog.Disabled)
+}
+
+// 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
+}

sample-conf.yaml

@@ -1,4 +1,6 @@
 listenaddr: "localhost:8081"
+debuglevel: "debug"
+
 services:
   # List of services that should be reachable behind the proxy.
   # Requests will be matched to the services in order, picking the first