exhttp: add middleware utility

Signed-off-by: Sumner Evans <[email protected]>

exhttp/middleware.go

@@ -0,0 +1,17 @@
+package exhttp
+
+import "net/http"
+
+// Middleware represents a middleware that can be applied to an [http.Handler].
+type Middleware func(http.Handler) http.Handler
+
+// ApplyMiddleware applies the provided [Middleware] functions to the given
+// router. The middlewares will be applied in the order they are provided.
+func ApplyMiddleware(router http.Handler, middlewares ...Middleware) http.Handler {
+	// Apply middlewares in reverse order because the first middleware provided
+	// needs to be the outermost one.
+	for i := len(middlewares) - 1; i >= 0; i-- {
+		router = middlewares[i](router)
+	}
+	return router
+}