gin/README_ZH.md
2018-07-13 16:24:54 +08:00

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Gin Web Framework

Build Status codecov Go Report Card GoDoc Join the chat at https://gitter.im/gin-gonic/gin Open Source Helpers

Gin 是一个用 Go 语言编写的 WEB 框架。它具有和 maritini 类似的 API 并拥有更好的性能, 感谢 httprouter 使它的速度提升了 40 倍。如果你需要性能和良好的生产力,你将会爱上 Gin 。

Gin console logger

Contents

安装

要安装 Gin 包,你需要先安装 Go 并且设置你的 Go 的工作工作空间。

  1. 下载并安装它:
$ go get -u github.com/gin-gonic/gin
  1. 在你的代码中导入它:
import "github.com/gin-gonic/gin"
  1. (可选的) 导入 net/http 。 如果你使用常量(如: http.StatusOK 的时候必须导入。
import "net/http"

使用一个 vendor 工具,比如 Govendor

  1. go get govendor
$ go get github.com/kardianos/govendor
  1. 创建你的项目目录并使用 cd 进入
$ mkdir -p $GOPATH/src/github.com/myusername/project && cd "$_"
  1. 初始化你的项目的 Vendor 并添加 gin
$ govendor init
$ govendor fetch github.com/gin-gonic/gin@v1.2
  1. 复制一个开始模板到你的项目中
$ curl https://raw.githubusercontent.com/gin-gonic/gin/master/examples/basic/main.go > main.go
  1. 运行你的项目
$ go run main.go

依赖

现在 Gin 需要 Go 1.6 或更高版本,并且它就将会需要 Go 1.7 。

快速开始

# 假设下面代码在 example.go 文件中
$ 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() // 在 0.0.0.0:8080 上监听并服务
}
# 运行 example.go 并在浏览器上访问 0.0.0.0:8080/ping
$ go run example.go

性能测试

Gin 采用一个 HttpRouter 的自定义版本

查看所有性能测试

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 在固定时间内重复完成的总数,数值越高的是越好的结果
  • 2 单次重复持续时间ns / op越低越好
  • 3 堆内存B / op越低越好
  • 4 每次重复的平均分配allocs / op越低越好

Gin v1. stable

  • 零分配路由
  • 仍然是最快的 http 路由器和框架, 从路由写入。
  • 完整的单元测试套件
  • 对战测试
  • API冻结新版本不会破坏您的代码。

使用 jsoniter 构建

Gin 使用 encoding/json 作为默认的 json 包,但是你可以在构建的时候通过 tags 去使用 jsoniter

$ go build -tags=jsoniter .

API 示例

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

func main() {
	// 禁用控制台颜色
	// gin.DisableConsoleColor()

	// 使用默认中间件创建一个 gin 路由:
	// 日志与恢复中间件(无崩溃)。
	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)

	// 默认情况下它使用8080除非定义了 PORT 环境变量。
	router.Run()
	// router.Run(":3000") 硬编码端口
}

path 中的参数

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

	// 这个处理器将去匹配 /user/john  但是它不会去匹配 /user
	router.GET("/user/:name", func(c *gin.Context) {
		name := c.Param("name")
		c.String(http.StatusOK, "Hello %s", name)
	})

	// 然而,这个将会匹配 /user/john 并且也会匹配 /user/john/send
	// 如果没有其他的路由匹配 /user/john  它将重定向到 /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")
}

请求参数

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

	// 请求参数使用现有的底层 request 对象解析。
	// 请求响应匹配的 URL /welcome?firstname=Jane&lastname=Doe
	router.GET("/welcome", func(c *gin.Context) {
		firstname := c.DefaultQuery("firstname", "Guest")
		// 这个是 c.Request.URL.Query().Get("lastname") 的快捷方式。
		lastname := c.Query("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")
}

其他示例: 请求参数 + 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

上传文件

单文件

参考 issue #774 与详细的 示例代码

func main() {
	router := gin.Default()
	// 为 multipart 表单设置一个较低的内存限制(默认是 32 MiB
	// router.MaxMultipartMemory = 8 << 20  // 8 MiB
	router.POST("/upload", func(c *gin.Context) {
		// 单文件
		file, _ := c.FormFile("file")
		log.Println(file.Filename)

		// 上传文件到指定的 dst 。
		// c.SaveUploadedFile(file, dst)

		c.String(http.StatusOK, fmt.Sprintf("'%s' uploaded!", file.Filename))
	})
	router.Run(":8080")
}

如何使用 curl:

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

多文件

See the detail example code.

func main() {
	router := gin.Default()
	// 为 multipart 表单设置一个较低的内存限制(默认是 32 MiB
	// router.MaxMultipartMemory = 8 << 20  // 8 MiB
	router.POST("/upload", func(c *gin.Context) {
		// Multipart form
		form, _ := c.MultipartForm()
		files := form.File["upload[]"]

		for _, file := range files {
			log.Println(file.Filename)

			// 上传文件到指定的 dst.
			// c.SaveUploadedFile(file, dst)
		}
		c.String(http.StatusOK, fmt.Sprintf("%d files uploaded!", len(files)))
	})
	router.Run(":8080")
}

如何使用 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"

组路由

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

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

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

	router.Run(":8080")
}

默认的没有中间件的空白 Gin

Use

r := gin.New()

代替

// Default 已经连接了 Logger 和 Recovery 中间件
r := gin.Default()

使用中间件

func main() {
	// 创建一个默认的没有任何中间件的路由
	r := gin.New()

	// 全局中间件
	// Logger 中间件将写日志到 gin.DefaultWriter ,即使你设置 GIN_MODE=release 。
	// 默认 gin.DefaultWriter = os.Stdout
	r.Use(gin.Logger())

	// Recovery 中间件从任何 panic 恢复,如果出现 panic它会写一个 500 错误。
	r.Use(gin.Recovery())

	// 每个路由的中间件, 你能添加任意数量的中间件
	r.GET("/benchmark", MyBenchLogger(), benchEndpoint)

	// 授权组
	// authorized := r.Group("/", AuthRequired())
	// 也可以这样:
	authorized := r.Group("/")
	// 每个组的中间件! 在这个实例中,我们只需要在 "authorized" 组中
	// 使用自定义创建的 AuthRequired() 中间件
	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)
	}

	// 监听并服务于 0.0.0.0:8080
	r.Run(":8080")
}

如何写入日志文件

func main() {
    // 禁用控制台颜色,当你将日志写入到文件的时候,你不需要控制台颜色。
    gin.DisableConsoleColor()

    // 写入日志的文件
    f, _ := os.Create("gin.log")
    gin.DefaultWriter = io.MultiWriter(f)

    // 如果你需要同时写入日志文件和控制台上显示,使用下面代码
    // gin.DefaultWriter = io.MultiWriter(f, os.Stdout)

    router := gin.Default()
    router.GET("/ping", func(c *gin.Context) {
        c.String(200, "pong")
    })

    router.Run(":8080")
}

模型绑定和验证

绑定一个请求主体到一个类型,使用模型绑定。我们目前支持 JSON 、 XML 和标准表单的值( foo=bar&boo=baz )的绑定。

Gin 使用 go-playground/validator.v8 进行验证。 在 这里 查看标签使用的完整文档。

注意: 你需要在你想要绑定的所有字段上设置相应的绑定标签。例如:当要从 JSON 绑定的时候,设置 json:"fieldname"

此外, Gin 提供了两组绑定方法:

  • 类型 - Must bind
    • 方法 - Bind, BindJSON, BindQuery
    • 行为 - 这些方法在 MustBindWith 引擎下面使用。如果存在绑定错误, 请求通过 c.AbortWithError(400, err).SetType(ErrorTypeBind) 被终止。 这组响应的状态吗被设置成 400 ,并将 Content-Type 头设置成 text/plain; charset=utf-8 。注意: 如果你尝试在这个之后去设置响应码,它会发出一个警告 [GIN-debug] [WARNING] Headers were already written. Wanted to override status code 400 with 422 。 如果你希望更好的控制行为, 请考虑使用 ShouldBind 等效的方法。
  • 类型 - Should bind
    • 方法 - ShouldBind, ShouldBindJSON, ShouldBindQuery
    • 行为 - 这些方法在 ShouldBindWith 引擎下使用。 如果存在绑定错误,这个错误会被返回, 需要开发者去处理相应的请求和错误。

当使用绑定方式时, Gin 会尝试通过 Content-Type 推断出绑定器的依赖,如果你要明确你绑定的什么,可以使用 MustBindWithShouldBindWith

你也可以指定需要指定的字段。如果一个字段使用 binding:"required" 修饰,并且当绑定的时候是一个空值的时候,将会返回一个错误。

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

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

	// 绑定 JSON 的示例 ({"user": "manu", "password": "123"})
	router.POST("/loginJSON", func(c *gin.Context) {
		var json Login
		if err := c.ShouldBindJSON(&json); err == 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"})
			}
		} else {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		}
	})

	// 一个 HTML 表单绑定的示例 (user=manu&password=123)
	router.POST("/loginForm", func(c *gin.Context) {
		var form Login
		// 这个将通过 content-type 头去推断绑定器使用哪个依赖。
		if err := c.ShouldBind(&form); err == 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"})
			}
		} else {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		}
	})

	// 监听并服务于 0.0.0.0:8080
	router.Run(":8080")
}

请求样本

$ curl -v -X POST \
  http://localhost:8080/loginJSON \
  -H 'content-type: application/json' \
  -d '{ "user": "manu" }'
> POST /loginJSON HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.51.0
> Accept: */*
> content-type: application/json
> Content-Length: 18
>
* upload completely sent off: 18 out of 18 bytes
< HTTP/1.1 400 Bad Request
< Content-Type: application/json; charset=utf-8
< Date: Fri, 04 Aug 2017 03:51:31 GMT
< Content-Length: 100
<
{"error":"Key: 'Login.Password' Error:Field validation for 'Password' failed on the 'required' tag"}

跳过验证

When running the above example using the above the curl command, it returns error. Because the example use binding:"required" for Password. If use binding:"-" for Password, then it will not return error when running the above example again.

Custom Validators

It is also possible to register custom validators. See the example code.

package main

import (
	"net/http"
	"reflect"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gin-gonic/gin/binding"
	"gopkg.in/go-playground/validator.v8"
)

type Booking struct {
	CheckIn  time.Time `form:"check_in" binding:"required,bookabledate" time_format:"2006-01-02"`
	CheckOut time.Time `form:"check_out" binding:"required,gtfield=CheckIn" time_format:"2006-01-02"`
}

func bookableDate(
	v *validator.Validate, topStruct reflect.Value, currentStructOrField reflect.Value,
	field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string,
) bool {
	if date, ok := field.Interface().(time.Time); ok {
		today := time.Now()
		if today.Year() > date.Year() || today.YearDay() > date.YearDay() {
			return false
		}
	}
	return true
}

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

	if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
		v.RegisterValidation("bookabledate", bookableDate)
	}

	route.GET("/bookable", getBookable)
	route.Run(":8085")
}

func getBookable(c *gin.Context) {
	var b Booking
	if err := c.ShouldBindWith(&b, binding.Query); err == nil {
		c.JSON(http.StatusOK, gin.H{"message": "Booking dates are valid!"})
	} else {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
	}
}
$ curl "localhost:8085/bookable?check_in=2018-04-16&check_out=2018-04-17"
{"message":"Booking dates are valid!"}

$ curl "localhost:8085/bookable?check_in=2018-03-08&check_out=2018-03-09"
{"error":"Key: 'Booking.CheckIn' Error:Field validation for 'CheckIn' failed on the 'bookabledate' tag"}

Struct level validations can also be registed this way. See the struct-lvl-validation example to learn more.

Only Bind Query String

ShouldBindQuery function only binds the query params and not the post data. See the detail information.

package main

import (
	"log"

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

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

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

func startPage(c *gin.Context) {
	var person Person
	if c.ShouldBindQuery(&person) == nil {
		log.Println("====== Only Bind By Query String ======")
		log.Println(person.Name)
		log.Println(person.Address)
	}
	c.String(200, "Success")
}

Bind Query String or Post Data

See the detail information.

package main

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

type Person struct {
	Name     string    `form:"name"`
	Address  string    `form:"address"`
	Birthday time.Time `form:"birthday" time_format:"2006-01-02" time_utc:"1"`
}

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.ShouldBind(&person) == nil {
		log.Println(person.Name)
		log.Println(person.Address)
		log.Println(person.Birthday)
	}

	c.String(200, "Success")
}

Test it with:

$ curl -X GET "localhost:8085/testing?name=appleboy&address=xyz&birthday=1992-03-15"

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.ShouldBind(&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.ShouldBindWith(&form, binding.Form)
		// or you can simply use autobinding with ShouldBind method:
		var form LoginForm
		// in this case proper binding will be automatically selected
		if c.ShouldBind(&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")
}

JSONP

Using JSONP to request data from a server in a different domain. Add callback to response body if the query parameter callback exists.

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

	r.GET("/JSONP?callback=x", func(c *gin.Context) {
		data := map[string]interface{}{
			"foo": "bar",
		}

		//callback is x
		// Will output  :   x({\"foo\":\"bar\"})
		c.JSONP(http.StatusOK, data)
	})

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

AsciiJSON

Using AsciiJSON to Generates ASCII-only JSON with escaped non-ASCII chracters.

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

	r.GET("/someJSON", func(c *gin.Context) {
		data := map[string]interface{}{
			"lang": "GO语言",
			"tag":  "<br>",
		}

		// will output : {"lang":"GO\u8bed\u8a00","tag":"\u003cbr\u003e"}
		c.AsciiJSON(http.StatusOK, data)
	})

	// 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")
}

Serving data from reader

func main() {
	router := gin.Default()
	router.GET("/someDataFromReader", func(c *gin.Context) {
		response, err := http.Get("https://raw.githubusercontent.com/gin-gonic/logo/master/color.png")
		if err != nil || response.StatusCode != http.StatusOK {
			c.Status(http.StatusServiceUnavailable)
			return
		}

		reader := response.Body
		contentLength := response.ContentLength
		contentType := response.Header.Get("Content-Type")

		extraHeaders := map[string]string{
			"Content-Disposition": `attachment; filename="gopher.png"`,
		}

		c.DataFromReader(http.StatusOK, contentLength, contentType, reader, extraHeaders)
	})
	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

See the detail example code.

main.go

import (
    "fmt"
    "html/template"
    "net/http"
    "time"

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

func formatAsDate(t time.Time) string {
    year, month, day := t.Date()
    return fmt.Sprintf("%d%02d/%02d", year, month, day)
}

func main() {
    router := gin.Default()
    router.Delims("{[{", "}]}")
    router.SetFuncMap(template.FuncMap{
        "formatAsDate": formatAsDate,
    })
    router.LoadHTMLFiles("./fixtures/basic/raw.tmpl")

    router.GET("/raw", func(c *gin.Context) {
        c.HTML(http.StatusOK, "raw.tmpl", map[string]interface{}{
            "now": time.Date(2017, 07, 01, 0, 0, 0, 0, time.UTC),
        })
    })

    router.Run(":8080")
}

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. Both internal and external locations are supported.

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

Issuing a Router redirect, use HandleContext like below.

r.GET("/test", func(c *gin.Context) {
    c.Request.URL.Path = "/test2"
    r.HandleContext(c)
})
r.GET("/test2", func(c *gin.Context) {
    c.JSON(200, gin.H{"hello": "world"})
})

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 new Goroutines 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))
}

Run multiple service using Gin

See the question and try the following example:

package main

import (
	"log"
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
	"golang.org/x/sync/errgroup"
)

var (
	g errgroup.Group
)

func router01() http.Handler {
	e := gin.New()
	e.Use(gin.Recovery())
	e.GET("/", func(c *gin.Context) {
		c.JSON(
			http.StatusOK,
			gin.H{
				"code":  http.StatusOK,
				"error": "Welcome server 01",
			},
		)
	})

	return e
}

func router02() http.Handler {
	e := gin.New()
	e.Use(gin.Recovery())
	e.GET("/", func(c *gin.Context) {
		c.JSON(
			http.StatusOK,
			gin.H{
				"code":  http.StatusOK,
				"error": "Welcome server 02",
			},
		)
	})

	return e
}

func main() {
	server01 := &http.Server{
		Addr:         ":8080",
		Handler:      router01(),
		ReadTimeout:  5 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	server02 := &http.Server{
		Addr:         ":8081",
		Handler:      router02(),
		ReadTimeout:  5 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	g.Go(func() error {
		return server01.ListenAndServe()
	})

	g.Go(func() error {
		return server02.ListenAndServe()
	})

	if err := g.Wait(); err != nil {
		log.Fatal(err)
	}
}

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 && err != http.ErrServerClosed {
			log.Fatalf("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 exiting")
}

Build a single binary with templates

You can build a server into a single binary containing templates by using go-assets.

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

	t, err := loadTemplate()
	if err != nil {
		panic(err)
	}
	r.SetHTMLTemplate(t)

	r.GET("/", func(c *gin.Context) {
		c.HTML(http.StatusOK, "/html/index.tmpl",nil)
	})
	r.Run(":8080")
}

// loadTemplate loads templates embedded by go-assets-builder
func loadTemplate() (*template.Template, error) {
	t := template.New("")
	for name, file := range Assets.Files {
		if file.IsDir() || !strings.HasSuffix(name, ".tmpl") {
			continue
		}
		h, err := ioutil.ReadAll(file)
		if err != nil {
			return nil, err
		}
		t, err = t.New(name).Parse(string(h))
		if err != nil {
			return nil, err
		}
	}
	return t, nil
}

See a complete example in the examples/assets-in-binary directory.

Bind form-data request with custom struct

The follow example using custom struct:

type StructA struct {
    FieldA string `form:"field_a"`
}

type StructB struct {
    NestedStruct StructA
    FieldB string `form:"field_b"`
}

type StructC struct {
    NestedStructPointer *StructA
    FieldC string `form:"field_c"`
}

type StructD struct {
    NestedAnonyStruct struct {
        FieldX string `form:"field_x"`
    }
    FieldD string `form:"field_d"`
}

func GetDataB(c *gin.Context) {
    var b StructB
    c.Bind(&b)
    c.JSON(200, gin.H{
        "a": b.NestedStruct,
        "b": b.FieldB,
    })
}

func GetDataC(c *gin.Context) {
    var b StructC
    c.Bind(&b)
    c.JSON(200, gin.H{
        "a": b.NestedStructPointer,
        "c": b.FieldC,
    })
}

func GetDataD(c *gin.Context) {
    var b StructD
    c.Bind(&b)
    c.JSON(200, gin.H{
        "x": b.NestedAnonyStruct,
        "d": b.FieldD,
    })
}

func main() {
    r := gin.Default()
    r.GET("/getb", GetDataB)
    r.GET("/getc", GetDataC)
    r.GET("/getd", GetDataD)

    r.Run()
}

Using the command curl command result:

$ curl "http://localhost:8080/getb?field_a=hello&field_b=world"
{"a":{"FieldA":"hello"},"b":"world"}
$ curl "http://localhost:8080/getc?field_a=hello&field_c=world"
{"a":{"FieldA":"hello"},"c":"world"}
$ curl "http://localhost:8080/getd?field_x=hello&field_d=world"
{"d":"world","x":{"FieldX":"hello"}}

NOTE: NOT support the follow style struct:

type StructX struct {
    X struct {} `form:"name_x"` // HERE have form
}

type StructY struct {
    Y StructX `form:"name_y"` // HERE hava form
}

type StructZ struct {
    Z *StructZ `form:"name_z"` // HERE hava form
}

In a word, only support nested custom struct which have no form now.

Try to bind body into different structs

The normal methods for binding request body consumes c.Request.Body and they cannot be called multiple times.

type formA struct {
  Foo string `json:"foo" xml:"foo" binding:"required"`
}

type formB struct {
  Bar string `json:"bar" xml:"bar" binding:"required"`
}

func SomeHandler(c *gin.Context) {
  objA := formA{}
  objB := formB{}
  // This c.ShouldBind consumes c.Request.Body and it cannot be reused.
  if errA := c.ShouldBind(&objA); errA == nil {
    c.String(http.StatusOK, `the body should be formA`)
  // Always an error is occurred by this because c.Request.Body is EOF now.
  } else if errB := c.ShouldBind(&objB); errB == nil {
    c.String(http.StatusOK, `the body should be formB`)
  } else {
    ...
  }
}

For this, you can use c.ShouldBindBodyWith.

func SomeHandler(c *gin.Context) {
  objA := formA{}
  objB := formB{}
  // This reads c.Request.Body and stores the result into the context.
  if errA := c.ShouldBindBodyWith(&objA, binding.JSON); errA == nil {
    c.String(http.StatusOK, `the body should be formA`)
  // At this time, it reuses body stored in the context.
  } else if errB := c.ShouldBindBodyWith(&objB, binding.JSON); errB == nil {
    c.String(http.StatusOK, `the body should be formB JSON`)
  // And it can accepts other formats
  } else if errB2 := c.ShouldBindBodyWith(&objB, binding.XML); errB2 == nil {
    c.String(http.StatusOK, `the body should be formB XML`)
  } else {
    ...
  }
}
  • c.ShouldBindBodyWith stores body into the context before binding. This has a slight impact to performance, so you should not use this method if you are enough to call binding at once.
  • This feature is only needed for some formats -- JSON, XML, MsgPack, ProtoBuf. For other formats, Query, Form, FormPost, FormMultipart, can be called by c.ShouldBind() multiple times without any damage to performance (See #1341).

http2 server push

http.Pusher is supported only go1.8+. See the golang blog for detail information.

package main

import (
	"html/template"
	"log"

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

var html = template.Must(template.New("https").Parse(`
<html>
<head>
  <title>Https Test</title>
  <script src="/assets/app.js"></script>
</head>
<body>
  <h1 style="color:red;">Welcome, Ginner!</h1>
</body>
</html>
`))

func main() {
	r := gin.Default()
	r.Static("/assets", "./assets")
	r.SetHTMLTemplate(html)

	r.GET("/", func(c *gin.Context) {
		if pusher := c.Writer.Pusher(); pusher != nil {
			// use pusher.Push() to do server push
			if err := pusher.Push("/assets/app.js", nil); err != nil {
				log.Printf("Failed to push: %v", err)
			}
		}
		c.HTML(200, "https", gin.H{
			"status": "success",
		})
	})

	// Listen and Server in https://127.0.0.1:8080
	r.RunTLS(":8080", "./testdata/server.pem", "./testdata/server.key")
}

Testing

The net/http/httptest package is preferable way for HTTP testing.

package main

func setupRouter() *gin.Engine {
	r := gin.Default()
	r.GET("/ping", func(c *gin.Context) {
		c.String(200, "pong")
	})
	return r
}

func main() {
	r := setupRouter()
	r.Run(":8080")
}

Test for code example above:

package main

import (
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestPingRoute(t *testing.T) {
	router := setupRouter()

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/ping", nil)
	router.ServeHTTP(w, req)

	assert.Equal(t, 200, w.Code)
	assert.Equal(t, "pong", w.Body.String())
}

Users Sourcegraph

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.