/negroni

Idiomatic HTTP Middleware for Golang

Primary LanguageGoMIT LicenseMIT

Negroni GoDoc wercker status

Negroni is an idiomatic approach to web middleware in Go. It is tiny, non-intrusive, and encourages use of net/http Handlers.

If you like the idea of Martini, but you think it contains too much magic, then Negroni is a great fit.

Language Translations:

Getting Started

After installing Go and setting up your GOPATH, create your first .go file. We'll call it server.go.

package main

import (
  "github.com/codegangsta/negroni"
  "net/http"
  "fmt"
)

func main() {
  mux := http.NewServeMux()
  mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
    fmt.Fprintf(w, "Welcome to the home page!")
  })

  n := negroni.Classic()
  n.UseHandler(mux)
  n.Run(":3000")
}

Then install the Negroni package (go 1.1 and greater is required):

go get github.com/codegangsta/negroni

Then run your server:

go run server.go

You will now have a Go net/http webserver running on localhost:3000.

Need Help?

If you have a question or feature request, go ask the mailing list. The GitHub issues for Negroni will be used exclusively for bug reports and pull requests.

Is Negroni a Framework?

Negroni is not a framework. It is a library that is designed to work directly with net/http.

Routing?

Negroni is BYOR (Bring your own Router). The Go community already has a number of great http routers available, Negroni tries to play well with all of them by fully supporting net/http. For instance, integrating with Gorilla Mux looks like so:

router := mux.NewRouter()
router.HandleFunc("/", HomeHandler)

n := negroni.New(Middleware1, Middleware2)
// Or use a middleware with the Use() function
n.Use(Middleware3)
// router goes last
n.UseHandler(router)

n.Run(":3000")

negroni.Classic()

negroni.Classic() provides some default middleware that is useful for most applications:

  • negroni.Recovery - Panic Recovery Middleware.
  • negroni.Logging - Request/Response Logging Middleware.
  • negroni.Static - Static File serving under the "public" directory.

This makes it really easy to get started with some useful features from Negroni.

Handlers

Negroni provides a bidirectional middleware flow. This is done through the negroni.Handler interface:

type Handler interface {
  ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)
}

If a middleware hasn't already written to the ResponseWriter, it should call the next http.HandlerFunc in the chain to yield to the next middleware handler. This can be used for great good:

func MyMiddleware(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
  // do some stuff before
  next(rw, r)
  // do some stuff after
}

And you can map it to the handler chain with the Use function:

n := negroni.New()
n.Use(negroni.HandlerFunc(MyMiddleware))

You can also map plain old http.Handlers:

n := negroni.New()

mux := http.NewServeMux()
// map your routes

n.UseHandler(mux)

n.Run(":3000")

Run()

Negroni has a convenience function called Run. Run takes an addr string identical to http.ListenAndServe.

n := negroni.Classic()
// ...
log.Fatal(http.ListenAndServe(":8080", n))

Route Specific Middleware

If you have a route group of routes that need specific middleware to be executed, you can simply create a new Negroni instance and use it as your route handler.

router := mux.NewRouter()
adminRoutes := mux.NewRouter()
// add admin routes here

// Create a new negroni for the admin middleware
router.Handle("/admin", negroni.New(
  Middleware1,
  Middleware2,
  negroni.Wrap(adminRoutes),
))

Third Party Middleware

Here is a current list of Negroni compatible middlware. Feel free to put up a PR linking your middleware if you have built one:

Middleware Author Description
RestGate Prasanga Siripala Secure authentication for REST API endpoints
Graceful Tyler Bunnell Graceful HTTP Shutdown
secure Cory Jacobsen Middleware that implements a few quick security wins
JWT Middleware Auth0 Middleware checks for a JWT on the Authorization header on incoming requests and decodes it
binding Matt Holt Data binding from HTTP requests into structs
logrus Dan Buch Logrus-based logger
render Cory Jacobsen Render JSON, XML and HTML templates
gorelic Jingwen Owen Ou New Relic agent for Go runtime
gzip phyber GZIP response compression
oauth2 David Bochenski oAuth2 middleware
sessions David Bochenski Session Management
permissions2 Alexander Rødseth Cookies, users and permissions
onthefly Alexander Rødseth Generate TinySVG, HTML and CSS on the fly
cors Olivier Poitrey Cross Origin Resource Sharing (CORS) support
xrequestid Andrea Franz Middleware that assigns a random X-Request-Id header to each request
VanGoH Taylor Wrobel Configurable AWS-Style HMAC authentication middleware
stats Florent Messa Store information about your web application (response time, etc.)

Examples

Alexander Rødseth created mooseware, a skeleton for writing a Negroni middleware handler.

Live code reload?

gin and fresh both live reload negroni apps.

Essential Reading for Beginners of Go & Negroni

About

Negroni is obsessively designed by none other than the Code Gangsta