Files
SciMesh/users/internal/infra/logging.go
T
2026-07-26 14:38:24 +03:00

66 lines
1.6 KiB
Go

package infra
import (
"fmt"
"io"
"log/slog"
"os"
"path/filepath"
"strings"
"gopkg.in/natefinch/lumberjack.v2"
)
// NewLogger builds the process logger.
//
// It always writes JSON to stdout, so `docker logs` and any 12-factor log
// collector keep working. When LogFile is set it *also* writes to a
// size-rotated file, so logs survive a container rebuild instead of vanishing
// with the previous stdout stream. Rotation is delegated to lumberjack rather
// than hand-rolled.
//
// The returned Closer flushes and closes the file; call it on shutdown.
func NewLogger(cfg Config) (*slog.Logger, io.Closer, error) {
opts := &slog.HandlerOptions{Level: parseLevel(cfg.LogLevel)}
var (
out io.Writer = os.Stdout
closer io.Closer = noopCloser{}
)
if cfg.LogFile != "" {
if err := os.MkdirAll(filepath.Dir(cfg.LogFile), 0o750); err != nil {
return nil, nil, fmt.Errorf("create log directory: %w", err)
}
rotator := &lumberjack.Logger{
Filename: cfg.LogFile,
MaxSize: 50, // megabytes before a rotation
MaxBackups: 5, // keep this many rotated files
MaxAge: 30, // days
Compress: true,
}
// Tee to both: the console stays live while the file is the durable copy.
out = io.MultiWriter(os.Stdout, rotator)
closer = rotator
}
return slog.New(slog.NewJSONHandler(out, opts)), closer, nil
}
func parseLevel(s string) slog.Level {
switch strings.ToLower(strings.TrimSpace(s)) {
case "debug":
return slog.LevelDebug
case "warn", "warning":
return slog.LevelWarn
case "error":
return slog.LevelError
default:
return slog.LevelInfo
}
}
type noopCloser struct{}
func (noopCloser) Close() error { return nil }