Request size middleware (#808) (#809)

middleware/request_size.go

@@ -0,0 +1,18 @@
+package middleware
+
+import (
+	"net/http"
+)
+
+// RequestSize is a middleware that will limit request sizes to a specified
+// number of bytes. It uses MaxBytesReader to do so.
+func RequestSize(bytes int64) func(http.Handler) http.Handler {
+	f := func(h http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			r.Body = http.MaxBytesReader(w, r.Body, bytes)
+			h.ServeHTTP(w, r)
+		}
+		return http.HandlerFunc(fn)
+	}
+	return f
+}