gin/README.md

Gin Web Framework

Gin is a web framework written in Go (Golang). It features a martini-like API with much better performance, up to 40 times faster thanks to httprouter. If you need performance and good productivity, you will love Gin.

# assume the following codes in example.go file
$ cat example.go

package main

import "github.com/gin-gonic/gin"

func main() {
	r := gin.Default()
	r.GET("/ping", func(c *gin.Context) {
		c.JSON(200, gin.H{
			"message": "pong",
		})
	})
	r.Run() // listen and serve on 0.0.0.0:8080
}

# run example.go and visit 0.0.0.0:8080/ping on browser
$ go run example.go

Benchmarks

Gin uses a custom version of HttpRouter

See all benchmarks

Benchmark name	(1)	(2)	(3)	(4)
BenchmarkGin_GithubAll	30000	48375	0	0
BenchmarkAce_GithubAll	10000	134059	13792	167
BenchmarkBear_GithubAll	5000	534445	86448	943
BenchmarkBeego_GithubAll	3000	592444	74705	812
BenchmarkBone_GithubAll	200	6957308	698784	8453
BenchmarkDenco_GithubAll	10000	158819	20224	167
BenchmarkEcho_GithubAll	10000	154700	6496	203
BenchmarkGocraftWeb_GithubAll	3000	570806	131656	1686
BenchmarkGoji_GithubAll	2000	818034	56112	334
BenchmarkGojiv2_GithubAll	2000	1213973	274768	3712
BenchmarkGoJsonRest_GithubAll	2000	785796	134371	2737
BenchmarkGoRestful_GithubAll	300	5238188	689672	4519
BenchmarkGorillaMux_GithubAll	100	10257726	211840	2272
BenchmarkHttpRouter_GithubAll	20000	105414	13792	167
BenchmarkHttpTreeMux_GithubAll	10000	319934	65856	671
BenchmarkKocha_GithubAll	10000	209442	23304	843
BenchmarkLARS_GithubAll	20000	62565	0	0
BenchmarkMacaron_GithubAll	2000	1161270	204194	2000
BenchmarkMartini_GithubAll	200	9991713	226549	2325
BenchmarkPat_GithubAll	200	5590793	1499568	27435
BenchmarkPossum_GithubAll	10000	319768	84448	609
BenchmarkR2router_GithubAll	10000	305134	77328	979
BenchmarkRivet_GithubAll	10000	132134	16272	167
BenchmarkTango_GithubAll	3000	552754	63826	1618
BenchmarkTigerTonic_GithubAll	1000	1439483	239104	5374
BenchmarkTraffic_GithubAll	100	11383067	2659329	21848
BenchmarkVulcan_GithubAll	5000	394253	19894	609

(1): Total Repetitions achieved in constant time, higher means more confident result
(2): Single Repetition Duration (ns/op), lower is better
(3): Heap Memory (B/op), lower is better
(4): Average Allocations per Repetition (allocs/op), lower is better

Gin v1. stable

• Zero allocation router.
• Still the fastest http router and framework. From routing to writing.
• Complete suite of unit tests
• Battle tested
• API frozen, new releases will not break your code.

Start using it

1. Download and install it:

$ go get github.com/gin-gonic/gin

2. Import it in your code:

import "github.com/gin-gonic/gin"

3. (Optional) Import net/http. This is required for example if using constants such as http.StatusOK.

import "net/http"

Use a vendor tool like Govendor

1. go get govendor

$ go get github.com/kardianos/govendor

2. Create your project folder and cd inside

$ mkdir -p ~/go/src/github.com/myusername/project && cd "$_"

3. Vendor init your project and add gin

$ govendor init
$ govendor fetch github.com/gin-gonic/gin@v1.2

4. Copy a starting template inside your project

$ curl https://raw.githubusercontent.com/gin-gonic/gin/master/examples/basic/main.go > main.go

5. Run your project

$ go run main.go

Build with jsoniter

Gin use encoding/json as default json package but you can change to jsoniter by build from other tags.

$ go build -tags=jsoniter .

API Examples

Using GET, POST, PUT, PATCH, DELETE and OPTIONS

func main() {
	// Disable Console Color
	// gin.DisableConsoleColor()

	// Creates a gin router with default middleware:
	// logger and recovery (crash-free) middleware
	router := gin.Default()

	router.GET("/someGet", getting)
	router.POST("/somePost", posting)
	router.PUT("/somePut", putting)
	router.DELETE("/someDelete", deleting)
	router.PATCH("/somePatch", patching)
	router.HEAD("/someHead", head)
	router.OPTIONS("/someOptions", options)

	// By default it serves on :8080 unless a
	// PORT environment variable was defined.
	router.Run()
	// router.Run(":3000") for a hard coded port
}

Parameters in path

func main() {
	router := gin.Default()

	// This handler will match /user/john but will not match neither /user/ or /user
	router.GET("/user/:name", func(c *gin.Context) {
		name := c.Param("name")
		c.String(http.StatusOK, "Hello %s", name)
	})

	// However, this one will match /user/john/ and also /user/john/send
	// If no other routers match /user/john, it will redirect to /user/john/
	router.GET("/user/:name/*action", func(c *gin.Context) {
		name := c.Param("name")
		action := c.Param("action")
		message := name + " is " + action
		c.String(http.StatusOK, message)
	})

	router.Run(":8080")
}

Querystring parameters

func main() {
	router := gin.Default()

	// Query string parameters are parsed using the existing underlying request object.
	// The request responds to a url matching:  /welcome?firstname=Jane&lastname=Doe
	router.GET("/welcome", func(c *gin.Context) {
		firstname := c.DefaultQuery("firstname", "Guest")
		lastname := c.Query("lastname") // shortcut for c.Request.URL.Query().Get("lastname")

		c.String(http.StatusOK, "Hello %s %s", firstname, lastname)
	})
	router.Run(":8080")
}

Multipart/Urlencoded Form

func main() {
	router := gin.Default()

	router.POST("/form_post", func(c *gin.Context) {
		message := c.PostForm("message")
		nick := c.DefaultPostForm("nick", "anonymous")

		c.JSON(200, gin.H{
			"status":  "posted",
			"message": message,
			"nick":    nick,
		})
	})
	router.Run(":8080")
}

Another example: query + post form

POST /post?id=1234&page=1 HTTP/1.1
Content-Type: application/x-www-form-urlencoded

name=manu&message=this_is_great

func main() {
	router := gin.Default()

	router.POST("/post", func(c *gin.Context) {

		id := c.Query("id")
		page := c.DefaultQuery("page", "0")
		name := c.PostForm("name")
		message := c.PostForm("message")

		fmt.Printf("id: %s; page: %s; name: %s; message: %s", id, page, name, message)
	})
	router.Run(":8080")
}

id: 1234; page: 1; name: manu; message: this_is_great

Upload files

Single file

References issue #774 and detail example code.

func main() {
	router := gin.Default()
	router.POST("/upload", func(c *gin.Context) {
		// single file
		file, _ := c.FormFile("file")
		log.Println(file.Filename)
        
		// Upload the file to specific dst.
		// c.SaveUploadedFile(file, dst)       
		
		c.String(http.StatusOK, fmt.Sprintf("'%s' uploaded!", file.Filename))
	})
	router.Run(":8080")
}

How to curl:

curl -X POST http://localhost:8080/upload \
  -F "file=@/Users/appleboy/test.zip" \
  -H "Content-Type: multipart/form-data"

Multiple files

See the detail example code.

func main() {
	router := gin.Default()
	router.POST("/upload", func(c *gin.Context) {
		// Multipart form
		form, _ := c.MultipartForm()
		files := form.File["upload[]"]

		for _, file := range files {
			log.Println(file.Filename)
			
			// Upload the file to specific dst.
			// c.SaveUploadedFile(file, dst)       
		}
		c.String(http.StatusOK, fmt.Sprintf("%d files uploaded!", len(files)))
	})
	router.Run(":8080")
}

How to curl:

curl -X POST http://localhost:8080/upload \
  -F "upload[]=@/Users/appleboy/test1.zip" \
  -F "upload[]=@/Users/appleboy/test2.zip" \
  -H "Content-Type: multipart/form-data"

Grouping routes

func main() {
	router := gin.Default()

	// Simple group: v1
	v1 := router.Group("/v1")
	{
		v1.POST("/login", loginEndpoint)
		v1.POST("/submit", submitEndpoint)
		v1.POST("/read", readEndpoint)
	}

	// Simple group: v2
	v2 := router.Group("/v2")
	{
		v2.POST("/login", loginEndpoint)
		v2.POST("/submit", submitEndpoint)
		v2.POST("/read", readEndpoint)
	}

	router.Run(":8080")
}

Blank Gin without middleware by default

Use

r := gin.New()

instead of

r := gin.Default()

Using middleware

func main() {
	// Creates a router without any middleware by default
	r := gin.New()

	// Global middleware
	r.Use(gin.Logger())
	r.Use(gin.Recovery())

	// Per route middleware, you can add as many as you desire.
	r.GET("/benchmark", MyBenchLogger(), benchEndpoint)

	// Authorization group
	// authorized := r.Group("/", AuthRequired())
	// exactly the same as:
	authorized := r.Group("/")
	// per group middleware! in this case we use the custom created
	// AuthRequired() middleware just in the "authorized" group.
	authorized.Use(AuthRequired())
	{
		authorized.POST("/login", loginEndpoint)
		authorized.POST("/submit", submitEndpoint)
		authorized.POST("/read", readEndpoint)

		// nested group
		testing := authorized.Group("testing")
		testing.GET("/analytics", analyticsEndpoint)
	}

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

Model binding and validation

To bind a request body into a type, use model binding. We currently support binding of JSON, XML and standard form values (foo=bar&boo=baz).

Gin uses go-playground/validator.v8 for validation. Check the full docs on tags usage here.

Note that you need to set the corresponding binding tag on all fields you want to bind. For example, when binding from JSON, set json:"fieldname".

When using the Bind-method, Gin tries to infer the binder depending on the Content-Type header. If you are sure what you are binding, you can use BindWith.

You can also specify that specific fields are required. If a field is decorated with binding:"required" and has a empty value when binding, the current request will fail with an error.

// Binding from JSON
type Login struct {
	User     string `form:"user" json:"user" binding:"required"`
	Password string `form:"password" json:"password" binding:"required"`
}

func main() {
	router := gin.Default()

	// Example for binding JSON ({"user": "manu", "password": "123"})
	router.POST("/loginJSON", func(c *gin.Context) {
		var json Login
		if c.BindJSON(&json) == nil {
			if json.User == "manu" && json.Password == "123" {
				c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})
			} else {
				c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
			}
		}
	})

	// Example for binding a HTML form (user=manu&password=123)
	router.POST("/loginForm", func(c *gin.Context) {
		var form Login
		// This will infer what binder to use depending on the content-type header.
		if c.Bind(&form) == nil {
			if form.User == "manu" && form.Password == "123" {
				c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})
			} else {
				c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
			}
		}
	})

	// Listen and serve on 0.0.0.0:8080
	router.Run(":8080")
}

Bind Query String

See the detail information.

package main

import "log"
import "github.com/gin-gonic/gin"

type Person struct {
	Name    string `form:"name"`
	Address string `form:"address"`
}

func main() {
	route := gin.Default()
	route.GET("/testing", startPage)
	route.Run(":8085")
}

func startPage(c *gin.Context) {
	var person Person
	// If `GET`, only `Form` binding engine (`query`) used.
	// If `POST`, first checks the `content-type` for `JSON` or `XML`, then uses `Form` (`form-data`).
	// See more at https://github.com/gin-gonic/gin/blob/master/binding/binding.go#L48
	if c.Bind(&person) == nil {
		log.Println(person.Name)
		log.Println(person.Address)
	}

	c.String(200, "Success")
}

Bind HTML checkboxes

See the detail information

main.go

...

type myForm struct {
    Colors []string `form:"colors[]"`
}

...

func formHandler(c *gin.Context) {
    var fakeForm myForm
    c.Bind(&fakeForm)
    c.JSON(200, gin.H{"color": fakeForm.Colors})
}

...

form.html

<form action="/" method="POST">
    <p>Check some colors</p>
    <label for="red">Red</label>
    <input type="checkbox" name="colors[]" value="red" id="red" />
    <label for="green">Green</label>
    <input type="checkbox" name="colors[]" value="green" id="green" />
    <label for="blue">Blue</label>
    <input type="checkbox" name="colors[]" value="blue" id="blue" />
    <input type="submit" />
</form>

result:

{"color":["red","green","blue"]}

Multipart/Urlencoded binding

package main

import (
	"github.com/gin-gonic/gin"
)

type LoginForm struct {
	User     string `form:"user" binding:"required"`
	Password string `form:"password" binding:"required"`
}

func main() {
	router := gin.Default()
	router.POST("/login", func(c *gin.Context) {
		// you can bind multipart form with explicit binding declaration:
		// c.MustBindWith(&form, binding.Form)
		// or you can simply use autobinding with Bind method:
		var form LoginForm
		// in this case proper binding will be automatically selected
		if c.Bind(&form) == nil {
			if form.User == "user" && form.Password == "password" {
				c.JSON(200, gin.H{"status": "you are logged in"})
			} else {
				c.JSON(401, gin.H{"status": "unauthorized"})
			}
		}
	})
	router.Run(":8080")
}

Test it with:

$ curl -v --form user=user --form password=password http://localhost:8080/login

XML, JSON and YAML rendering

func main() {
	r := gin.Default()

	// gin.H is a shortcut for map[string]interface{}
	r.GET("/someJSON", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})
	})

	r.GET("/moreJSON", func(c *gin.Context) {
		// You also can use a struct
		var msg struct {
			Name    string `json:"user"`
			Message string
			Number  int
		}
		msg.Name = "Lena"
		msg.Message = "hey"
		msg.Number = 123
		// Note that msg.Name becomes "user" in the JSON
		// Will output  :   {"user": "Lena", "Message": "hey", "Number": 123}
		c.JSON(http.StatusOK, msg)
	})

	r.GET("/someXML", func(c *gin.Context) {
		c.XML(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})
	})

	r.GET("/someYAML", func(c *gin.Context) {
		c.YAML(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

SecureJSON

Using SecureJSON to prevent json hijacking. Default prepends "while(1)," to response body if the given struct is array values.

func main() {
	r := gin.Default()

	// You can also use your own secure json prefix
	// r.SecureJsonPrefix(")]}',\n")

	r.GET("/someJSON", func(c *gin.Context) {
		names := []string{"lena", "austin", "foo"}

		// Will output  :   while(1);["lena","austin","foo"]
		c.SecureJSON(http.StatusOK, names)
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

Serving static files

func main() {
	router := gin.Default()
	router.Static("/assets", "./assets")
	router.StaticFS("/more_static", http.Dir("my_file_system"))
	router.StaticFile("/favicon.ico", "./resources/favicon.ico")

	// Listen and serve on 0.0.0.0:8080
	router.Run(":8080")
}

HTML rendering

Using LoadHTMLGlob() or LoadHTMLFiles()

func main() {
	router := gin.Default()
	router.LoadHTMLGlob("templates/*")
	//router.LoadHTMLFiles("templates/template1.html", "templates/template2.html")
	router.GET("/index", func(c *gin.Context) {
		c.HTML(http.StatusOK, "index.tmpl", gin.H{
			"title": "Main website",
		})
	})
	router.Run(":8080")
}

templates/index.tmpl

<html>
	<h1>
		{{ .title }}
	</h1>
</html>

Using templates with same name in different directories

func main() {
	router := gin.Default()
	router.LoadHTMLGlob("templates/**/*")
	router.GET("/posts/index", func(c *gin.Context) {
		c.HTML(http.StatusOK, "posts/index.tmpl", gin.H{
			"title": "Posts",
		})
	})
	router.GET("/users/index", func(c *gin.Context) {
		c.HTML(http.StatusOK, "users/index.tmpl", gin.H{
			"title": "Users",
		})
	})
	router.Run(":8080")
}

templates/posts/index.tmpl

{{ define "posts/index.tmpl" }}
<html><h1>
	{{ .title }}
</h1>
<p>Using posts/index.tmpl</p>
</html>
{{ end }}

templates/users/index.tmpl

{{ define "users/index.tmpl" }}
<html><h1>
	{{ .title }}
</h1>
<p>Using users/index.tmpl</p>
</html>
{{ end }}

Custom Template renderer

You can also use your own html template render

import "html/template"

func main() {
	router := gin.Default()
	html := template.Must(template.ParseFiles("file1", "file2"))
	router.SetHTMLTemplate(html)
	router.Run(":8080")
}

Custom Delimiters

You may use custom delims

	r := gin.Default()
	r.Delims("{[{", "}]}")
	r.LoadHTMLGlob("/path/to/templates"))

Custom Template Funcs

main.go

	...
	
	func formatAsDate(t time.Time) string {
		year, month, day := t.Date()
		return fmt.Sprintf("%d/%02d/%02d", year, month, day)
	}
	
	...
	
	router.SetFuncMap(template.FuncMap{
		"formatAsDate": formatAsDate,
	})
	
	...
	
	router.GET("/raw", func(c *Context) {
		c.HTML(http.StatusOK, "raw.tmpl", map[string]interface{}{
			"now": time.Date(2017, 07, 01, 0, 0, 0, 0, time.UTC),
		})
	})
	
	...

raw.tmpl

Date: {[{.now | formatAsDate}]}

Result:

Date: 2017/07/01

Multitemplate

Gin allow by default use only one html.Template. Check a multitemplate render for using features like go 1.6 block template.

Redirects

Issuing a HTTP redirect is easy:

r.GET("/test", func(c *gin.Context) {
	c.Redirect(http.StatusMovedPermanently, "http://www.google.com/")
})

Both internal and external locations are supported.

Custom Middleware

func Logger() gin.HandlerFunc {
	return func(c *gin.Context) {
		t := time.Now()

		// Set example variable
		c.Set("example", "12345")

		// before request

		c.Next()

		// after request
		latency := time.Since(t)
		log.Print(latency)

		// access the status we are sending
		status := c.Writer.Status()
		log.Println(status)
	}
}

func main() {
	r := gin.New()
	r.Use(Logger())

	r.GET("/test", func(c *gin.Context) {
		example := c.MustGet("example").(string)

		// it would print: "12345"
		log.Println(example)
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

Using BasicAuth() middleware

// simulate some private data
var secrets = gin.H{
	"foo":    gin.H{"email": "foo@bar.com", "phone": "123433"},
	"austin": gin.H{"email": "austin@example.com", "phone": "666"},
	"lena":   gin.H{"email": "lena@guapa.com", "phone": "523443"},
}

func main() {
	r := gin.Default()

	// Group using gin.BasicAuth() middleware
	// gin.Accounts is a shortcut for map[string]string
	authorized := r.Group("/admin", gin.BasicAuth(gin.Accounts{
		"foo":    "bar",
		"austin": "1234",
		"lena":   "hello2",
		"manu":   "4321",
	}))

	// /admin/secrets endpoint
	// hit "localhost:8080/admin/secrets
	authorized.GET("/secrets", func(c *gin.Context) {
		// get user, it was set by the BasicAuth middleware
		user := c.MustGet(gin.AuthUserKey).(string)
		if secret, ok := secrets[user]; ok {
			c.JSON(http.StatusOK, gin.H{"user": user, "secret": secret})
		} else {
			c.JSON(http.StatusOK, gin.H{"user": user, "secret": "NO SECRET :("})
		}
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

Goroutines inside a middleware

When starting inside a middleware or handler, you SHOULD NOT use the original context inside it, you have to use a read-only copy.

func main() {
	r := gin.Default()

	r.GET("/long_async", func(c *gin.Context) {
		// create copy to be used inside the goroutine
		cCp := c.Copy()
		go func() {
			// simulate a long task with time.Sleep(). 5 seconds
			time.Sleep(5 * time.Second)

			// note that you are using the copied context "cCp", IMPORTANT
			log.Println("Done! in path " + cCp.Request.URL.Path)
		}()
	})

	r.GET("/long_sync", func(c *gin.Context) {
		// simulate a long task with time.Sleep(). 5 seconds
		time.Sleep(5 * time.Second)

		// since we are NOT using a goroutine, we do not have to copy the context
		log.Println("Done! in path " + c.Request.URL.Path)
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}

Custom HTTP configuration

Use http.ListenAndServe() directly, like this:

func main() {
	router := gin.Default()
	http.ListenAndServe(":8080", router)
}

or

func main() {
	router := gin.Default()

	s := &http.Server{
		Addr:           ":8080",
		Handler:        router,
		ReadTimeout:    10 * time.Second,
		WriteTimeout:   10 * time.Second,
		MaxHeaderBytes: 1 << 20,
	}
	s.ListenAndServe()
}

Support Let's Encrypt

example for 1-line LetsEncrypt HTTPS servers.

package main

import (
	"log"

	"github.com/gin-gonic/autotls"
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()

	// Ping handler
	r.GET("/ping", func(c *gin.Context) {
		c.String(200, "pong")
	})

	log.Fatal(autotls.Run(r, "example1.com", "example2.com"))
}

example for custom autocert manager.

package main

import (
	"log"

	"github.com/gin-gonic/autotls"
	"github.com/gin-gonic/gin"
	"golang.org/x/crypto/acme/autocert"
)

func main() {
	r := gin.Default()

	// Ping handler
	r.GET("/ping", func(c *gin.Context) {
		c.String(200, "pong")
	})

	m := autocert.Manager{
		Prompt:     autocert.AcceptTOS,
		HostPolicy: autocert.HostWhitelist("example1.com", "example2.com"),
		Cache:      autocert.DirCache("/var/www/.cache"),
	}

	log.Fatal(autotls.RunWithManager(r, &m))
}

Graceful restart or stop

Do you want to graceful restart or stop your web server? There are some ways this can be done.

We can use fvbock/endless to replace the default ListenAndServe. Refer issue #296 for more details.

router := gin.Default()
router.GET("/", handler)
// [...]
endless.ListenAndServe(":4242", router)

An alternative to endless:

• manners: A polite Go HTTP server that shuts down gracefully.
• graceful: Graceful is a Go package enabling graceful shutdown of an http.Handler server.
• grace: Graceful restart & zero downtime deploy for Go servers.

If you are using Go 1.8, you may not need to use this library! Consider using http.Server's built-in Shutdown() method for graceful shutdowns. See the full graceful-shutdown example with gin.

// +build go1.8

package main

import (
	"context"
	"log"
	"net/http"
	"os"
	"os/signal"
	"time"

	"github.com/gin-gonic/gin"
)

func main() {
	router := gin.Default()
	router.GET("/", func(c *gin.Context) {
		time.Sleep(5 * time.Second)
		c.String(http.StatusOK, "Welcome Gin Server")
	})

	srv := &http.Server{
		Addr:    ":8080",
		Handler: router,
	}

	go func() {
		// service connections
		if err := srv.ListenAndServe(); err != nil {
			log.Printf("listen: %s\n", err)
		}
	}()

	// Wait for interrupt signal to gracefully shutdown the server with
	// a timeout of 5 seconds.
	quit := make(chan os.Signal)
	signal.Notify(quit, os.Interrupt)
	<-quit
	log.Println("Shutdown Server ...")

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := srv.Shutdown(ctx); err != nil {
		log.Fatal("Server Shutdown:", err)
	}
	log.Println("Server exist")
}

Users

Awesome project lists using Gin web framework.

• drone: Drone is a Continuous Delivery platform built on Docker, written in Go
• gorush: A push notification server written in Go.