Middlewares

Fuego supports net/http middlewares.

It means that all existing middlewares for net/http, including the ones from chi and gorilla can be used with Fuego! 🔥

You can use them to add functionalities to your routes, such as logging, authentication, etc.

Middlewares can be registered at 2 levels:

• Route middlewares: applies only to registered routes, is scoped to a specific group, or several routes.
• Global middlewares: applied on every request, even non-matching routes (useful for CORS for example).

Route middlewares

You can add middlewares to a single route. They are treated as an option to the route handler. They will be added in the http.ServeMux in the order they are declared, when registering the route.

main.go

package main

import (
	"github.com/go-fuego/fuego"
)

func main() {
	s := fuego.NewServer()

	// Declare the middlewares after the route handler
	fuego.Get(s, "/", myController,
		option.QueryInt("page", "The page number"),
		option.Middleware(middleware1),
		option.Middleware(middleware2, middleware3),
	)

	s.Run()
}

Apply on group or server

To mimic the well-known Use method from chi and Gin, Fuego provides a Use method to add middlewares to a Group or Server. They are treated as an option to the server or group handler and will be applied to all routes.

But we recommend using the option.Middleware method for better readability.

main.go

package main

import (
	"net/http"

	"github.com/go-fuego/fuego"
)

func main() {
	s := fuego.NewServer()

	// Add a middleware to the whole server
	fuego.Use(s, func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Do something before the request
			next.ServeHTTP(w, r)
			// Do something after the request
		})
	})

	fuego.Use(s, myMiddleware)

	fuego.Get(s, "/", myController)

	s.Run()
}

main.go

package main

import (
	"net/http"

	"github.com/go-fuego/fuego"
)

func main() {
	s := fuego.NewServer()

	// Add a middleware to a group of routes
	api := fuego.Group(s, "/api")

	fuego.Use(api, func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Do something before the request
			// Only affects routes in the group
			next.ServeHTTP(w, r)
			// Do something after the request
		})
	})

	// Requests to /api will go through the middleware
	fuego.Get(api, "/", myController)

	// Requests to / will NOT! go through the middleware
	fuego.Get(s, "/", myController)

	s.Run()
}

Global Middlewares

Global middlewares are applied to every request, even if the route does not match. They are useful for CORS, for example as CORS are using the OPTION method even if not registered. They are registered in the Server Handler, not the Mux, and just before Run is called (not at route registration).

main.go

package main

import (
	"net/http"

	"github.com/go-fuego/fuego"
)

func main() {
	s := fuego.NewServer()

	// Add a global middleware
	fuego.WithGlobalMiddlewares(func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.Header().Set("X-Hello", "World")
			// Do something before the request
			next.ServeHTTP(w, r)
			// Do something after the request
		})
	})

	fuego.Get(s, "/my-route", myController)

	// Here, the global middleware is applied
	s.Run()
}

This will work even if the user requests a route that does not exist:

curl -v -X GET http://localhost:3000/unknown-route

We can see the X-Hello: World header in the response.