loggie

loggie 🧠⚡️ — Context-Aware Logger for Go

Context-aware, pluggable logger for Go web applications.
No more passing logger through every function — just use context.Context.

🚀 What is loggie?

loggie helps you embed a structured logger inside context.Context, so you can log from any layer — service, repository, or handler — with a consistent trace_id, user_id, or any custom field.

It supports Zap, Logrus, OpenTelemetry, and works with any web framework.

✨ Features

✅ Structured logging via context.Context
✅ Auto-generated trace_id per request
✅ OTEL-compatible (extracts trace_id from spans)
✅ Custom fields via loggie.WithCustomField()
✅ Framework-agnostic logger injection
✅ Zap / Logrus support
✅ No-op fallback logger
✅ Fx lifecycle and context cancellation compatible

📦 Installation

go get github.com/ditthkr/loggie

🧠 Injecting Logger in Middleware

Use loggie.Injection(ctx, logger) inside any middleware, from any web framework.

ctx, traceId := loggie.Injection(req.Context(), logger)

✅ Fiber

app.Use(func(c *fiber.Ctx) error {
	ctx, traceId := loggie.Injection(c.UserContext(), logger)
	c.SetUserContext(ctx)
	c.Set("X-Trace-Id", traceId)
	return c.Next()
})

✅ Gin

r.Use(func(c *gin.Context) {
	ctx, traceId := loggie.Injection(c.Request.Context(), logger)
	c.Request = c.Request.WithContext(ctx)
	c.Writer.Header().Set("X-Trace-Id", traceId)
	c.Next()
})

✅ Echo

e.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
	return func(c echo.Context) error {
		ctx, traceId := loggie.Injection(c.Request().Context(), logger)
		req := c.Request().WithContext(ctx)
		c.SetRequest(req)
		c.Response().Header().Set("X-Trace-Id", traceId)
		return next(c)
	}
})

🔌 Logger Interface

type Logger interface {
    Info(msg string, fields ...any)
    Error(msg string, fields ...any)
    With(fields ...any) Logger
}

✅ Supported Adapters

📄 Usage Example

log := loggie.FromContext(ctx)
log.Info("Order created", "user_id", 123)

📤 Output (Zap or Logrus):

{
  "msg": "Order created",
  "trace_id": "...",
  "user_id": 123
}

🧰 Utilities

🌐 OpenTelemetry Support

If a context already contains an OTEL span, loggie will extract its trace_id:

span := trace.SpanFromContext(ctx)
traceId := span.SpanContext().TraceId().String()

You don’t need to do anything extra — TraceId(ctx) handles it automatically.

📃 License

MIT © 2025 @ditthkr