Initial Commit

2 files changed, 131 insertions, 0 deletions

diff --git a/logging/handler/handler.go b/logging/handler/handler.go
new file mode 100644
index 0000000..1501715
--- /dev/null
+++ b/logging/handler/handler.go
@@ -0,0 +1,75 @@
+package handler
+
+import (
+	"go-pkg-server/logging"
+	"log/slog"
+	"net/http"
+	"time"
+)
+
+type traceWriter struct {
+	http.ResponseWriter
+	status int
+	bytes  int
+}
+
+var _ http.ResponseWriter = &traceWriter{}
+
+func (t *traceWriter) Write(b []byte) (int, error) {
+	if t.status == 0 {
+		t.WriteHeader(http.StatusOK)
+	}
+	c, err := t.ResponseWriter.Write(b)
+	t.bytes += c
+	return c, err
+}
+
+func (tw *traceWriter) WriteHeader(statusCode int) {
+	if tw.status == 0 {
+		tw.status = http.StatusOK
+	}
+	tw.status = statusCode
+	tw.ResponseWriter.WriteHeader(statusCode)
+}
+
+func New(next http.Handler) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		ctx := r.Context()
+		logger := logging.FromContext(ctx)
+
+		defer func() {
+			err := recover()
+			if err != nil {
+				logging.RecoverLog(ctx, err)
+				http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			}
+		}()
+
+		logger = logger.With("method", r.Method,
+			"host", r.Host,
+			"remote_address", r.RemoteAddr,
+			"path", r.RequestURI,
+		)
+
+		ctx = logging.WithLogger(ctx, logger)
+
+		r = r.WithContext(ctx)
+
+		tw := &traceWriter{ResponseWriter: w}
+		
+		start := time.Now()
+		next.ServeHTTP(tw, r)
+		duration := time.Since(start)
+
+		logger.Log(ctx, slog.LevelInfo, "Request Handled",
+			"protocol", r.Proto,
+			"bytes_recieved", r.ContentLength,
+			"status", tw.status,
+			"time", duration,
+			"bytes_sent", tw.bytes,
+			"user_agent", r.UserAgent(),
+			"referer", r.Referer(),
+		)
+
+	}
+}
diff --git a/logging/log.go b/logging/log.go
new file mode 100644
index 0000000..8e3078f
--- /dev/null
+++ b/logging/log.go
@@ -0,0 +1,56 @@
+package logging
+
+import (
+	"context"
+	"io"
+	"log/slog"
+	"os"
+	"runtime"
+)
+
+type Config struct {
+	Level slog.Level `toml:"level"`
+	File  string     `toml:"file"`
+}
+
+func SetupLogger(cfg Config) *slog.Logger {
+	opts := &slog.HandlerOptions{Level: cfg.Level}
+	var handler slog.Handler
+
+	var writter io.Writer
+	writter = os.Stdout
+	if cfg.File != "" {
+		f, _ := os.OpenFile(cfg.File, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+		writter = f
+	}
+	handler = slog.NewJSONHandler(writter, opts)
+
+	logger := slog.New(handler)
+	slog.SetDefault(logger)
+	return logger
+}
+
+type contextKeyType struct{}
+
+var contextKey contextKeyType
+
+func WithLogger(ctx context.Context, logger *slog.Logger) context.Context {
+	return context.WithValue(ctx, contextKey, logger)
+}
+
+func FromContext(ctx context.Context) *slog.Logger {
+	if logger, ok := ctx.Value(contextKey).(*slog.Logger); ok {
+		return logger
+	}
+	return slog.Default()
+}
+
+func RecoverLog(ctx context.Context, err any) {
+	logger := FromContext(ctx)
+
+	const size = 64 << 10
+	buf := make([]byte, size)
+	buf = buf[:runtime.Stack(buf, false)]
+
+	logger.Log(ctx, slog.LevelError, "Program Paniced", "error", err, "stack", string(buf))
+}