config: add --nofilelogging option.

config.go

@@ -91,6 +91,7 @@ type config struct {
 	ConfigFile           string        `short:"C" long:"configfile" description:"Path to configuration file"`
 	DataDir              string        `short:"b" long:"datadir" description:"Directory to store data"`
 	LogDir               string        `long:"logdir" description:"Directory to log output."`
+	NoFileLogging        bool          `long:"nofilelogging" description:"Disable file logging."`
 	AddPeers             []string      `short:"a" long:"addpeer" description:"Add a peer to connect with at startup"`
 	ConnectPeers         []string      `long:"connect" description:"Connect only to the specified peers at startup"`
 	DisableListen        bool          `long:"nolisten" description:"Disable listening for incoming connections -- NOTE: Listening is automatically disabled if the --connect or --proxy options are used without also specifying listen interfaces via --listen"`
@@ -602,11 +603,17 @@ func loadConfig() (*config, []string, error) {
 	var oldTestNets []string
 	oldTestNets = append(oldTestNets, filepath.Join(cfg.DataDir, "testnet"))
 	cfg.DataDir = filepath.Join(cfg.DataDir, netName(activeNetParams))
+	logRotator = nil
+	if !cfg.NoFileLogging {
+		// Append the network type to the log directory so it is "namespaced"
+		// per network in the same fashion as the data directory.
+		cfg.LogDir = cleanAndExpandPath(cfg.LogDir)
+		cfg.LogDir = filepath.Join(cfg.LogDir, netName(activeNetParams))
 
-	// Append the network type to the log directory so it is "namespaced"
-	// per network in the same fashion as the data directory.
-	cfg.LogDir = cleanAndExpandPath(cfg.LogDir)
-	cfg.LogDir = filepath.Join(cfg.LogDir, netName(activeNetParams))
+		// Initialize log rotation.  After log rotation has been initialized, the
+		// logger variables may be used.
+		initLogRotator(filepath.Join(cfg.LogDir, defaultLogFilename))
+	}
 
 	// Special show command to list supported subsystems and exit.
 	if cfg.DebugLevel == "show" {
@@ -614,10 +621,6 @@ func loadConfig() (*config, []string, error) {
 		os.Exit(0)
 	}
 
-	// Initialize log rotation.  After log rotation has been initialized, the
-	// logger variables may be used.
-	initLogRotator(filepath.Join(cfg.LogDir, defaultLogFilename))
-
 	// Parse, validate, and set debug log level(s).
 	if err := parseAndSetDebugLevels(cfg.DebugLevel); err != nil {
 		err := fmt.Errorf("%s: %v", funcName, err.Error())

dcrd.go

@@ -53,6 +53,9 @@ func dcrdMain(serverChan chan<- *server) error {
 	// Show version and home dir at startup.
 	dcrdLog.Infof("Version %s (Go version %s)", version(), runtime.Version())
 	dcrdLog.Infof("Home dir: %s", cfg.HomeDir)
+	if cfg.NoFileLogging {
+		dcrdLog.Info("File logging disabled")
+	}
 
 	// Enable http profiling server if requested.
 	if cfg.Profile != "" {

doc.go

@@ -26,6 +26,7 @@ Application Options:
   -C, --configfile=         Path to configuration file
   -b, --datadir=            Directory to store data
       --logdir=             Directory to log output.
+      --nofilelogging=      Disable file logging.
   -a, --addpeer=            Add a peer to connect with at startup
       --connect=            Connect only to the specified peers at startup
       --nolisten            Disable listening for incoming connections -- NOTE:

log.go

@@ -35,7 +35,9 @@ type logWriter struct{}
 
 func (logWriter) Write(p []byte) (n int, err error) {
 	os.Stdout.Write(p)
-	logRotator.Write(p)
+	if logRotator != nil {
+		logRotator.Write(p)
+	}
 	return len(p), nil
 }
 
@@ -166,6 +168,8 @@ func directionString(inbound bool) string {
 func fatalf(str string) {
 	dcrdLog.Errorf("Unable to create profiler: %v", str)
 	os.Stdout.Sync()
-	logRotator.Close()
+	if logRotator != nil {
+		logRotator.Close()
+	}
 	os.Exit(1)
 }