multi: move ParseAndSetDebugLevels out of ValidateConfig

We need to move the call that sets all log levels out of the config
validation. Otherwise this will overwrite all subsystem log levels in
LiT where we call the faraday.ValidateConfig() function but have already
set up our loggers.

At the same time we remove the unnecessary global logWriter variable.

config.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/btcsuite/btcutil"
 	"github.com/lightninglabs/lndclient"
-	"github.com/lightningnetwork/lnd/build"
 	"github.com/lightningnetwork/lnd/cert"
 	"github.com/lightningnetwork/lnd/lncfg"
 	"github.com/lightningnetwork/lnd/lnrpc"
@@ -290,10 +289,6 @@ func ValidateConfig(config *Config) error {
 		)
 	}
 
-	if err := build.ParseAndSetDebugLevels(config.DebugLevel, logWriter); err != nil {
-		return err
-	}
-
 	return nil
 }
 

faraday.go

@@ -40,8 +40,14 @@ func Main() error {
 	if err != nil {
 		return err
 	}
+
+	// Setup logging before parsing the config.
 	logWriter := build.NewRotatingLogWriter()
 	SetupLoggers(logWriter, shutdownInterceptor)
+	err = build.ParseAndSetDebugLevels(config.DebugLevel, logWriter)
+	if err != nil {
+		return err
+	}
 
 	if err := ValidateConfig(&config); err != nil {
 		return fmt.Errorf("error validating config: %v", err)

log.go

@@ -17,8 +17,6 @@ import (
 const Subsystem = "FRDY"
 
 var (
-	logWriter *build.RotatingLogWriter
-
 	// 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.
@@ -29,7 +27,6 @@ var (
 func SetupLoggers(root *build.RotatingLogWriter, intercept signal.Interceptor) {
 	genLogger := genSubLogger(root, intercept)
 
-	logWriter = root
 	log = build.NewSubLogger(Subsystem, genLogger)
 
 	setSubLogger(root, Subsystem, log, nil)