Fixing review findings 4

Signed-off-by: Yuri Nikolic <[email protected]>

log/gokit.go

@@ -10,6 +10,7 @@ import (
 	"os"
 
 	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
 )
 
 const (
@@ -32,6 +33,14 @@ func NewGoKit(format string, writer io.Writer) log.Logger {
 	return log.NewLogfmtLogger(writer)
 }
 
+// NewGoKitWithLevel creates a new GoKit logger with the given level, format and writer.
+// If the given writer is nil, os.Stderr is used.
+// If the given format is nil, logfmt is used.
+func NewGoKitWithLevel(lvl Level, format string, writer io.Writer) log.Logger {
+	logger := NewGoKit(format, writer)
+	return level.NewFilter(logger, lvl.Option)
+}
+
 // stand-alone for test purposes
 func addStandardFields(logger log.Logger) log.Logger {
 	return log.With(logger, "ts", log.DefaultTimestampUTC, "caller", log.Caller(5))

server/server.go

@@ -236,7 +236,8 @@ func newServer(cfg Config, metrics *Metrics) (*Server, error) {
 	// If user doesn't supply a logging implementation, by default instantiate go-kit.
 	logger := cfg.Log
 	if logger == nil {
-		logger = log.NewGoKit(log.LogfmtFormat, os.Stderr)
+		writer := gokit_log.NewSyncWriter(os.Stderr)
+		logger = log.NewGoKitWithLevel(cfg.LogLevel, cfg.LogFormat, writer)
 	}
 
 	gatherer := cfg.Gatherer