logger/slog: add stacktrace support

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

logger/slog/slog.go

@@ -4,8 +4,10 @@ import (
 	"context"
 	"log/slog"
 	"os"
+	"regexp"
 	"runtime"
 	"strconv"
+	"sync"
 	"time"
 
 	"go.unistack.org/micro/v4/logger"
@@ -13,6 +15,8 @@ import (
 	"go.unistack.org/micro/v4/tracer"
 )
 
+var reTrace = regexp.MustCompile(`.*/slog/logger\.go.*\n`)
+
 var (
 	traceValue = slog.StringValue("trace")
 	debugValue = slog.StringValue("debug")
@@ -61,13 +65,15 @@ type slogLogger struct {
 	slog    *slog.Logger
 	leveler *slog.LevelVar
 	opts    logger.Options
+	mu      sync.RWMutex
 }
 
 func (s *slogLogger) Clone(opts ...options.Option) logger.Logger {
+	s.mu.RLock()
 	options := s.opts
 
 	for _, o := range opts {
-		o(&options)
+		_ = o(&options)
 	}
 
 	l := &slogLogger{
@@ -91,6 +97,8 @@ func (s *slogLogger) Clone(opts ...options.Option) logger.Logger {
 	handler := slog.NewJSONHandler(options.Out, handleOpt)
 	l.slog = slog.New(handler).With(options.Attrs...)
 
+	s.mu.RUnlock()
+
 	return l
 }
 
@@ -107,6 +115,7 @@ func (s *slogLogger) Options() logger.Options {
 }
 
 func (s *slogLogger) Attrs(attrs ...interface{}) logger.Logger {
+	s.mu.RLock()
 	nl := &slogLogger{opts: s.opts}
 	nl.leveler = new(slog.LevelVar)
 	nl.leveler.Set(s.leveler.Level())
@@ -120,6 +129,8 @@ func (s *slogLogger) Attrs(attrs ...interface{}) logger.Logger {
 	handler := slog.NewJSONHandler(s.opts.Out, handleOpt)
 	nl.slog = slog.New(handler).With(attrs...)
 
+	s.mu.RUnlock()
+
 	return nl
 }
 
@@ -219,6 +230,15 @@ func (s *slogLogger) Error(ctx context.Context, msg string, attrs ...interface{}
 	for _, fn := range s.opts.ContextAttrFuncs {
 		attrs = append(attrs, fn(ctx)...)
 	}
+	if s.opts.Stacktrace {
+		stackInfo := make([]byte, 1024*1024)
+		if stackSize := runtime.Stack(stackInfo, false); stackSize > 0 {
+			traceLines := reTrace.Split(string(stackInfo[:stackSize]), -1)
+			if len(traceLines) != 0 {
+				attrs = append(attrs, slog.String("stacktrace", traceLines[len(traceLines)-1]))
+			}
+		}
+	}
 	r.Add(attrs...)
 	r.Attrs(func(a slog.Attr) bool {
 		if a.Key == "error" {

logger/slog/slog_test.go

@@ -9,6 +9,19 @@ import (
 	"go.unistack.org/micro/v4/logger"
 )
 
+func TestError(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.ErrorLevel), logger.WithOutput(buf), logger.WithStacktrace(true))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	l.Error(ctx, "message")
+	if !bytes.Contains(buf.Bytes(), []byte(`"stacktrace":"`)) {
+		t.Fatalf("logger stacktrace not works, buf contains: %s", buf.Bytes())
+	}
+}
+
 func TestContext(t *testing.T) {
 	ctx := context.TODO()
 	buf := bytes.NewBuffer(nil)