初始提交：边缘AI算力机统一AI通讯层

internal/middleware/middleware.go

@@ -0,0 +1,104 @@
+package middleware
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"runtime/debug"
+	"time"
+
+	"github.com/edgeai/gateway/internal/observability"
+	"github.com/google/uuid"
+)
+
+type contextKey string
+
+const (
+	RequestIDKey contextKey = "request_id"
+)
+
+// RequestID middleware generates a unique request ID and sets it in context and response header.
+func RequestID(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		requestID := r.Header.Get("X-Request-ID")
+		if requestID == "" {
+			requestID = uuid.New().String()
+		}
+		w.Header().Set("X-Request-ID", requestID)
+		ctx := context.WithValue(r.Context(), RequestIDKey, requestID)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+// BodyLimit middleware rejects requests with bodies exceeding the given size.
+func BodyLimit(maxMB int) func(http.Handler) http.Handler {
+	maxBytes := int64(maxMB) * 1024 * 1024
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.ContentLength > maxBytes {
+				w.Header().Set("Content-Type", "application/json")
+				w.WriteHeader(http.StatusBadRequest)
+				fmt.Fprintf(w, `{"error":{"code":"INVALID_REQUEST","message":"request body exceeds %dMB limit"}}`, maxMB)
+				return
+			}
+			r.Body = http.MaxBytesReader(w, r.Body, maxBytes)
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// Recovery middleware catches panics and returns 500.
+func Recovery(logger *observability.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			defer func() {
+				if rec := recover(); rec != nil {
+					logger.Error("panic recovered",
+						observability.F().Event("panic").
+							RequestID(r.Header.Get("X-Request-ID")).
+							Reason(fmt.Sprintf("%v\n%s", rec, debug.Stack())))
+					http.Error(w, `{"error":{"code":"INTERNAL_ERROR","message":"internal server error"}}`,
+						http.StatusInternalServerError)
+				}
+			}()
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// Logging middleware logs request method, path, status, and duration.
+func Logging(logger *observability.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			rw := &responseWriter{ResponseWriter: w, status: 200}
+			next.ServeHTTP(rw, r)
+			logger.Info("http request",
+				observability.F().
+					Event("http_request").
+					RequestID(r.Header.Get("X-Request-ID")).
+					Set("method", r.Method).
+					Set("path", r.URL.Path).
+					Set("status", rw.status).
+					Set("duration_ms", time.Since(start).Milliseconds()))
+		})
+	}
+}
+
+type responseWriter struct {
+	http.ResponseWriter
+	status int
+}
+
+func (rw *responseWriter) WriteHeader(code int) {
+	rw.status = code
+	rw.ResponseWriter.WriteHeader(code)
+}
+
+// GetRequestID extracts the request ID from context.
+func GetRequestID(ctx context.Context) string {
+	if v, ok := ctx.Value(RequestIDKey).(string); ok {
+		return v
+	}
+	return ""
+}