gin

Gin Web Framework

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

Contents

• Gin Web Framework
  • Contents
  • Installation
  • Quick start
  • Benchmarks
  • Gin v1. stable
  • Build with json replacement
  • Build without MsgPack rendering feature
  • API Examples
    • Using GET, POST, PUT, PATCH, DELETE and OPTIONS
    • Parameters in path
    • Querystring parameters
    • Multipart/Urlencoded Form
    • Another example: query + post form
    • Map as querystring or postform parameters
    • Upload files
      • Single file
      • Multiple files

    • Grouping routes
    • Blank Gin without middleware by default
    • Using middleware
    • Custom Recovery behavior
    • How to write log file
    • Custom Log Format
    • Controlling Log output coloring
    • Model binding and validation
    • Custom Validators
    • Only Bind Query String
    • Bind Query String or Post Data
    • Bind Uri
    • Bind Header
    • Bind HTML checkboxes
    • Multipart/Urlencoded binding
    • XML, JSON, YAML and ProtoBuf rendering
      • SecureJSON
      • JSONP
      • AsciiJSON
      • PureJSON

    • Serving static files
    • Serving data from file
    • Serving data from reader
    • HTML rendering
      • Custom Template renderer
      • Custom Delimiters
      • Custom Template Funcs

    • Multitemplate
    • Redirects
    • Custom Middleware
    • Using BasicAuth() middleware
    • Goroutines inside a middleware
    • Custom HTTP configuration
    • Support Let's Encrypt
    • Run multiple service using Gin
    • Graceful shutdown or restart
      • Third-party packages
      • Manually

    • Build a single binary with templates
    • Bind form-data request with custom struct
    • Try to bind body into different structs
    • Bind form-data request with custom struct and custom tag
    • http2 server push
    • Define format for the log of routes
    • Set and get a cookie
  • Don't trust all proxies
  • Testing
  • Users

To install Gin package, you need to install Go and set your Go workspace first.

1. You first need Go installed (version 1.15+ is required), then you can use the below Go command to install Gin.

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

1. Import it in your code:

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

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

import "net/http"

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

package main


import (
  "net/http"

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

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

# run example.go and visit 0.0.0.0:8080/ping (for windows "localhost:8080/ping") on browser
$ go run example.go

Gin uses a custom version of HttpRouter

See all benchmarks

Benchmark name (1) (2) (3) (4)

BenchmarkGin_GithubAll 43550 27364 ns/op 0 B/op 0 allocs/op

BenchmarkAce_GithubAll 40543 29670 ns/op 0 B/op 0 allocs/op

BenchmarkAero_GithubAll 57632 20648 ns/op 0 B/op 0 allocs/op

BenchmarkBear_GithubAll 9234 216179 ns/op 86448 B/op 943 allocs/op

BenchmarkBeego_GithubAll 7407 243496 ns/op 71456 B/op 609 allocs/op

BenchmarkBone_GithubAll 420 2922835 ns/op 720160 B/op 8620 allocs/op

BenchmarkChi_GithubAll 7620 238331 ns/op 87696 B/op 609 allocs/op

BenchmarkDenco_GithubAll 18355 64494 ns/op 20224 B/op 167 allocs/op

BenchmarkEcho_GithubAll 31251 38479 ns/op 0 B/op 0 allocs/op

BenchmarkGocraftWeb_GithubAll 4117 300062 ns/op 131656 B/op 1686 allocs/op

BenchmarkGoji_GithubAll 3274 416158 ns/op 56112 B/op 334 allocs/op

BenchmarkGojiv2_GithubAll 1402 870518 ns/op 352720 B/op 4321 allocs/op

BenchmarkGoJsonRest_GithubAll 2976 401507 ns/op 134371 B/op 2737 allocs/op

BenchmarkGoRestful_GithubAll 410 2913158 ns/op 910144 B/op 2938 allocs/op

BenchmarkGorillaMux_GithubAll 346 3384987 ns/op 251650 B/op 1994 allocs/op

BenchmarkGowwwRouter_GithubAll 10000 143025 ns/op 72144 B/op 501 allocs/op

BenchmarkHttpRouter_GithubAll 55938 21360 ns/op 0 B/op 0 allocs/op

BenchmarkHttpTreeMux_GithubAll 10000 153944 ns/op 65856 B/op 671 allocs/op

BenchmarkKocha_GithubAll 10000 106315 ns/op 23304 B/op 843 allocs/op

BenchmarkLARS_GithubAll 47779 25084 ns/op 0 B/op 0 allocs/op

BenchmarkMacaron_GithubAll 3266 371907 ns/op 149409 B/op 1624 allocs/op

BenchmarkMartini_GithubAll 331 3444706 ns/op 226551 B/op 2325 allocs/op

BenchmarkPat_GithubAll 273 4381818 ns/op 1483152 B/op 26963 allocs/op

BenchmarkPossum_GithubAll 10000 164367 ns/op 84448 B/op 609 allocs/op

BenchmarkR2router_GithubAll 10000 160220 ns/op 77328 B/op 979 allocs/op

BenchmarkRivet_GithubAll 14625 82453 ns/op 16272 B/op 167 allocs/op

BenchmarkTango_GithubAll 6255 279611 ns/op 63826 B/op 1618 allocs/op

BenchmarkTigerTonic_GithubAll 2008 687874 ns/op 193856 B/op 4474 allocs/op

BenchmarkTraffic_GithubAll 355 3478508 ns/op 820744 B/op 14114 allocs/op

BenchmarkVulcan_GithubAll 6885 193333 ns/op 19894 B/op 609 allocs/op

• (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.

Build with json replacement

Gin uses encoding/json as default json package but you can change it by build from other tags.

jsoniter

go build -tags=jsoniter .

go-json

go build -tags=go_json .

sonic (you have to ensure that your cpu support avx instruction.)

$ go build -tags="sonic avx" .

Gin enables MsgPack rendering feature by default. But you can disable this feature by specifying nomsgpack build tag.

go build -tags=nomsgpack .

This is useful to reduce the binary size of executable files. See the detail information.

API Examples

You can find a number of ready-to-run examples at Gin examples repository.

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

func main() {
  // 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
}

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


// This handler will match /user/john but will not match /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)
  })

// For each matched request Context will hold the route definition
  router.POST("/user/:name/*action", func(c *gin.Context) {
    b := c.FullPath() == "/user/:name/*action" // true
    c.String(http.StatusOK, "%t", b)
  })

// This handler will add a new router for /user/groups.
  // Exact routes are resolved before param routes, regardless of the order they were defined.
  // Routes starting with /user/groups are never interpreted as /user/:name/... routes
  router.GET("/user/groups", func(c *gin.Context) {
    c.String(http.StatusOK, "The available groups are [...]")
  })

router.Run(":8080")
}

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")
}

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


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

c.JSON(http.StatusOK, gin.H{
  "status":  "posted",
  "message": message,
  "nick":    nick,
})


})
  router.Run(":8080")
}

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

POST /post?ids[a]=1234&ids[b]=hello HTTP/1.1
Content-Type: application/x-www-form-urlencoded


names[first]=thinkerou&names[second]=tianou

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


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

ids := c.QueryMap("ids")
names := c.PostFormMap("names")

fmt.Printf("ids: %v; names: %v", ids, names)


})
  router.Run(":8080")
}

ids: map[b:hello a:1234]; names: map[second:tianou first:thinkerou]

References issue #774 and detail example code.

file.Filename SHOULD NOT be trusted. See Content-Disposition on MDN and #1693

The filename is always optional and must not be used blindly by the application: path information should be stripped, and conversion to the server file system rules should be done.

func main() {
  router := gin.Default()
  // Set a lower memory limit for multipart forms (default is 32 MiB)
  router.MaxMultipartMemory = 8 << 20  // 8 MiB
  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"

See the detail example code.

func main() {
  router := gin.Default()
  // Set a lower memory limit for multipart forms (default is 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)

  // 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"

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")
}

Use

r := gin.New()

instead of

// Default With the Logger and Recovery middleware already attached
r := gin.Default()

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


// Global middleware
  // Logger middleware will write the logs to gin.DefaultWriter even if you set with GIN_MODE=release.
  // By default gin.DefaultWriter = os.Stdout
  r.Use(gin.Logger())

// Recovery middleware recovers from any panics and writes a 500 if there was one.
  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")
// visit 0.0.0.0:8080/testing/analytics
testing.GET("/analytics", analyticsEndpoint)


}

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

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


// Global middleware
  // Logger middleware will write the logs to gin.DefaultWriter even if you set with GIN_MODE=release.
  // By default gin.DefaultWriter = os.Stdout
  r.Use(gin.Logger())

// Recovery middleware recovers from any panics and writes a 500 if there was one.
  r.Use(gin.CustomRecovery(func(c *gin.Context, recovered interface{}) {
    if err, ok := recovered.(string); ok {
      c.String(http.StatusInternalServerError, fmt.Sprintf("error: %s", err))
    }
    c.AbortWithStatus(http.StatusInternalServerError)
  }))

r.GET("/panic", func(c *gin.Context) {
    // panic with a string -- the custom middleware could save this to a database or report it to the user
    panic("foo")
  })

r.GET("/", func(c *gin.Context) {
    c.String(http.StatusOK, "ohai")
  })

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

func main() {
    // Disable Console Color, you don't need console color when writing the logs to file.
    gin.DisableConsoleColor()


// Logging to a file.
f, _ := os.Create("gin.log")
gin.DefaultWriter = io.MultiWriter(f)

// Use the following code if you need to write the logs to file and console at the same time.
// gin.DefaultWriter = io.MultiWriter(f, os.Stdout)

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


   router.Run(":8080")
}

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


// LoggerWithFormatter middleware will write the logs to gin.DefaultWriter
  // By default gin.DefaultWriter = os.Stdout
  router.Use(gin.LoggerWithFormatter(func(param gin.LogFormatterParams) string {

// your custom format
return fmt.Sprintf("%s - [%s] \"%s %s %s %d %s \"%s\" %s\"\n",
    param.ClientIP,
    param.TimeStamp.Format(time.RFC1123),
    param.Method,
    param.Path,
    param.Request.Proto,
    param.StatusCode,
    param.Latency,
    param.Request.UserAgent(),
    param.ErrorMessage,
)


}))
  router.Use(gin.Recovery())

router.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
  })

router.Run(":8080")
}

Sample Output

::1 - [Fri, 07 Dec 2018 17:04:38 JST] "GET /ping HTTP/1.1 200 122.767µs "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.80 Safari/537.36" "

By default, logs output on console should be colorized depending on the detected TTY.

Never colorize logs:

func main() {
    // Disable log's color
    gin.DisableConsoleColor()


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

router.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":8080")


}

Always colorize logs:

func main() {
    // Force log's color
    gin.ForceConsoleColor()


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

router.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":8080")


}

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

Gin uses go-playground/validator/v10 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".

Also, Gin provides two sets of methods for binding:

• Type - Must bind
  • Methods - Bind, BindJSON, BindXML, BindQuery, BindYAML, BindHeader, BindTOML
  • Behavior - These methods use MustBindWith under the hood. If there is a binding error, the request is aborted with c.AbortWithError(400, err).SetType(ErrorTypeBind). This sets the response status code to 400 and the Content-Type header is set to text/plain; charset=utf-8. Note that if you try to set the response code after this, it will result in a warning [GIN-debug] [WARNING] Headers were already written. Wanted to override status code 400 with 422. If you wish to have greater control over the behavior, consider using the ShouldBind equivalent method.

• Type - Should bind
  • Methods - ShouldBind, ShouldBindJSON, ShouldBindXML, ShouldBindQuery, ShouldBindYAML, ShouldBindHeader, ShouldBindTOML,
  • Behavior - These methods use ShouldBindWith under the hood. If there is a binding error, the error is returned and it is the developer's responsibility to handle the request and error appropriately.

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 MustBindWith or ShouldBindWith.

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

// Binding from JSON
type Login struct {
  User     string form:"user" json:"user" xml:"user"  binding:"required"
  Password string form:"password" json:"password" xml:"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 err := c.ShouldBindJSON(&json); err != nil {
      c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
      return
    }

if json.User != "manu" || json.Password != "123" {
  c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
  return
}

c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})


})

// Example for binding XML (
  //  <?xml version="1.0" encoding="UTF-8"?>
  //  <root>
  //    <user>manu</user>
  //    <password>123</password>
  //  </root>)
  router.POST("/loginXML", func(c *gin.Context) {
    var xml Login
    if err := c.ShouldBindXML(&xml); err != nil {
      c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
      return
    }

if xml.User != "manu" || xml.Password != "123" {
  c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
  return
}

c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})


})

// 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 err := c.ShouldBind(&form); err != nil {
      c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
      return
    }

if form.User != "manu" || form.Password != "123" {
  c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
  return
}

c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})


})

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

Sample request

$ 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"}

Skip validate: 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.

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

package main


import (
  "net/http"
  "time"

"github.com/gin-gonic/gin"
  "github.com/gin-gonic/gin/binding"
  "github.com/go-playground/validator/v10"
)

// Booking contains binded and validated data.
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"
}

var bookableDate validator.Func = func(fl validator.FieldLevel) bool {
  date, ok := fl.Field().Interface().(time.Time)
  if ok {
    today := time.Now()
    if today.After(date) {
      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=2030-04-16&check_out=2030-04-17"
{"message":"Booking dates are valid!"}


$ curl "localhost:8085/bookable?check_in=2030-03-10&check_out=2030-03-09"
{"error":"Key: 'Booking.CheckOut' Error:Field validation for 'CheckOut' failed on the 'gtfield' tag"}

$ curl "localhost:8085/bookable?check_in=2000-03-09&check_out=2000-03-10"
{"error":"Key: 'Booking.CheckIn' Error:Field validation for 'CheckIn' failed on the 'bookabledate' tag"}%

Struct level validations can also be registered 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"
  "net/http"

"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(http.StatusOK, "Success")
}

See the detail information.

package main


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

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

type Person struct {
        Name       string    form:"name"
        Address    string    form:"address"
        Birthday   time.Time form:"birthday" time_format:"2006-01-02" time_utc:"1"
        CreateTime time.Time form:"createTime" time_format:"unixNano"
        UnixTime   time.Time form:"unixTime" time_format:"unix"
}

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#L88
        if c.ShouldBind(&person) == nil {
                log.Println(person.Name)
                log.Println(person.Address)
                log.Println(person.Birthday)
                log.Println(person.CreateTime)
                log.Println(person.UnixTime)
        }

c.String(http.StatusOK, "Success")
}

Test it with:

curl -X GET "localhost:8085/testing?name=appleboy&address=xyz&birthday=1992-03-15&createTime=1562400033000000123&unixTime=1562400033"

See the detail information.

package main


import (
  "net/http"

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

type Person struct {
  ID string uri:"id" binding:"required,uuid"
  Name string uri:"name" binding:"required"
}

func main() {
  route := gin.Default()
  route.GET("/:name/:id", func(c *gin.Context) {
    var person Person
    if err := c.ShouldBindUri(&person); err != nil {
      c.JSON(http.StatusBadRequest, gin.H{"msg": err.Error()})
      return
    }
    c.JSON(http.StatusOK, gin.H{"name": person.Name, "uuid": person.ID})
  })
  route.Run(":8088")
}

Test it with:

curl -v localhost:8088/thinkerou/987fbc97-4bed-5078-9f07-9141ba07c9f3
curl -v localhost:8088/thinkerou/not-uuid

package main


import (
  "fmt"
  "net/http"

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

type testHeader struct {
  Rate   int    header:"Rate"
  Domain string header:"Domain"
}

func main() {
  r := gin.Default()
  r.GET("/", func(c *gin.Context) {
    h := testHeader{}

if err := c.ShouldBindHeader(&h); err != nil {
  c.JSON(http.StatusOK, err)
}

fmt.Printf("%#v\n", h)
c.JSON(http.StatusOK, gin.H{"Rate": h.Rate, "Domain": h.Domain})


})

r.Run()

// client
// curl -H "rate:300" -H "domain:music" 127.0.0.1:8080/
// output
// {"Domain":"music","Rate":300}
}

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(http.StatusOK, 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"]}

type ProfileForm struct {
  Name   string                form:"name" binding:"required"
  Avatar *multipart.FileHeader form:"avatar" binding:"required"


// or for multiple files
  // Avatars []*multipart.FileHeader form:"avatar" binding:"required"
}

func main() {
  router := gin.Default()
  router.POST("/profile", 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 ProfileForm
    // in this case proper binding will be automatically selected
    if err := c.ShouldBind(&form); err != nil {
      c.String(http.StatusBadRequest, "bad request")
      return
    }

err := c.SaveUploadedFile(form.Avatar, form.Avatar.Filename)
if err != nil {
  c.String(http.StatusInternalServerError, "unknown error")
  return
}

// db.Save(&form)

c.String(http.StatusOK, "ok")


})
  router.Run(":8080")
}

Test it with:

curl -X POST -v --form name=user --form "avatar=@./avatar.png" http://localhost:8080/profile

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})
  })

r.GET("/someProtoBuf", func(c *gin.Context) {
    reps := []int64{int64(1), int64(2)}
    label := "test"
    // The specific definition of protobuf is written in the testdata/protoexample file.
    data := &protoexample.Test{
      Label: &label,
      Reps:  reps,
    }
    // Note that data becomes binary data in the response
    // Will output protoexample.Test protobuf serialized data
    c.ProtoBuf(http.StatusOK, data)
  })

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

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")
}

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", func(c *gin.Context) {
    data := gin.H{
      "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")

    // client
    // curl http://127.0.0.1:8080/JSONP?callback=x


}

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

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


r.GET("/someJSON", func(c *gin.Context) {
    data := gin.H{
      "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")
}

Normally, JSON replaces special HTML characters with their unicode entities, e.g. < becomes \u003c. If you want to encode such characters literally, you can use PureJSON instead. This feature is unavailable in Go 1.6 and lower.

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


// Serves unicode entities
  r.GET("/json", func(c *gin.Context) {
    c.JSON(http.StatusOK, gin.H{
      "html": "<b>Hello, world!</b>",
    })
  })

// Serves literal characters
  r.GET("/purejson", func(c *gin.Context) {
    c.PureJSON(http.StatusOK, gin.H{
      "html": "<b>Hello, world!</b>",
    })
  })

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

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")
  router.StaticFileFS("/more_favicon.ico", "more_favicon.ico", http.Dir("my_file_system"))


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

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


router.GET("/local/file", func(c *gin.Context) {
    c.File("local/file.go")
  })

var fs http.FileSystem = // ...
  router.GET("/fs/file", func(c *gin.Context) {
    c.FileFromFS("fs/file.go", fs)
  })
}

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
 defer reader.Close()
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")
}

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 }}

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")
}

You may use custom delims

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

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("./testdata/template/raw.tmpl")

router.GET("/raw", func(c *gin.Context) {
    c.HTML(http.StatusOK, "raw.tmpl", gin.H{
        "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

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 HTTP redirect from POST. Refer to issue: #444

r.POST("/test", func(c *gin.Context) {
  c.Redirect(http.StatusFound, "/foo")
})

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(http.StatusOK, gin.H{"hello": "world"})
})

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")
}

// 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")
}

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")
}

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()
}

example for 1-line LetsEncrypt HTTPS servers.

package main


import (
  "log"
  "net/http"

"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(http.StatusOK, "pong")
  })

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

example for custom autocert manager.

package main


import (
  "log"
  "net/http"

"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(http.StatusOK, "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))
}

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 {
    err := server01.ListenAndServe()
    if err != nil && err != http.ErrServerClosed {
      log.Fatal(err)
    }
    return err
  })

g.Go(func() error {
    err := server02.ListenAndServe()
    if err != nil && err != http.ErrServerClosed {
      log.Fatal(err)
    }
    return err
  })

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

There are a few approaches you can use to perform a graceful shutdown or restart. You can make use of third-party packages specifically built for that, or you can manually do the same with the functions and methods from the built-in packages.

Third-party packages

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

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

Alternatives:

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

Manually

In case you are using Go 1.8 or a later version, you may not need to use those libraries. Consider using http.Server's built-in Shutdown() method for graceful shutdowns. The example below describes its usage, and we've got more examples using gin here.

// +build go1.8


package main

import (
  "context"
  "log"
  "net/http"
  "os"
  "os/signal"
  "syscall"
  "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,
  }

// Initializing the server in a goroutine so that
  // it won't block the graceful shutdown handling below
  go func() {
    if err := srv.ListenAndServe(); err != nil && errors.Is(err, http.ErrServerClosed) {
      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)
  // kill (no param) default send syscall.SIGTERM
  // kill -2 is syscall.SIGINT
  // kill -9 is syscall.SIGKILL but can't be caught, so don't need to add it
  signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
  <-quit
  log.Println("Shutting down server...")

// The context is used to inform the server it has 5 seconds to finish
  // the request it is currently handling
  ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
  defer cancel()

if err := srv.Shutdown(ctx); err != nil {
    log.Fatal("Server forced to shutdown:", err)
  }

log.Println("Server exiting")
}

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 {
    defer file.Close()
    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 https://github.com/gin-gonic/examples/tree/master/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(http.StatusOK, gin.H{
        "a": b.NestedStruct,
        "b": b.FieldB,
    })
}

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

func GetDataD(c *gin.Context) {
    var b StructD
    c.Bind(&b)
    c.JSON(http.StatusOK, 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"}}

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.Form); 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 {
    ...
  }
}

1. 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.
2. 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).

Bind form-data request with custom struct and custom tag

const (
  customerTag = "url"
  defaultMemory = 32 << 20
)


type customerBinding struct {}

func (customerBinding) Name() string {
  return "form"
}

func (customerBinding) Bind(req *http.Request, obj interface{}) error {
  if err := req.ParseForm(); err != nil {
    return err
  }
  if err := req.ParseMultipartForm(defaultMemory); err != nil {
    if err != http.ErrNotMultipart {
      return err
    }
  }
  if err := binding.MapFormWithTag(obj, req.Form, customerTag); err != nil {
    return err
  }
  return validate(obj)
}

func validate(obj interface{}) error {
  if binding.Validator == nil {
    return nil
  }
  return binding.Validator.ValidateStruct(obj)
}

// Now we can do this!!!
// FormA is a external type that we can't modify it's tag
type FormA struct {
  FieldA string url:"field_a"
}

func ListHandler(s *Service) func(ctx *gin.Context) {
  return func(ctx *gin.Context) {
    var urlBinding = customerBinding{}
    var opt FormA
    err := ctx.MustBindWith(&opt, urlBinding)
    if err != nil {
      ...
    }
    ...
  }
}

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

package main


import (
  "html/template"
  "log"
  "net/http"

"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(http.StatusOK, "https", gin.H{
      "status": "success",
    })
  })

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

The default log of routes is:

[GIN-debug] POST   /foo                      --> main.main.func1 (3 handlers)
[GIN-debug] GET    /bar                      --> main.main.func2 (3 handlers)
[GIN-debug] GET    /status                   --> main.main.func3 (3 handlers)

If you want to log this information in given format (e.g. JSON, key values or something else), then you can define this format with gin.DebugPrintRouteFunc. In the example below, we log all routes with standard log package but you can use another log tools that suits of your needs.

import (
  "log"
  "net/http"


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

func main() {
  r := gin.Default()
  gin.DebugPrintRouteFunc = func(httpMethod, absolutePath, handlerName string, nuHandlers int) {
    log.Printf("endpoint %v %v %v %v\n", httpMethod, absolutePath, handlerName, nuHandlers)
  }

r.POST("/foo", func(c *gin.Context) {
    c.JSON(http.StatusOK, "foo")
  })

r.GET("/bar", func(c *gin.Context) {
    c.JSON(http.StatusOK, "bar")
  })

r.GET("/status", func(c *gin.Context) {
    c.JSON(http.StatusOK, "ok")
  })

// Listen and Server in http://0.0.0.0:8080
  r.Run()
}

import (
    "fmt"


"github.com/gin-gonic/gin"


)

func main() {

router := gin.Default()

router.GET("/cookie", func(c *gin.Context) {

    cookie, err := c.Cookie("gin_cookie")

    if err != nil {
        cookie = "NotSet"
        c.SetCookie("gin_cookie", "test", 3600, "/", "localhost", false, true)
    }

    fmt.Printf("Cookie value: %s \n", cookie)
})

router.Run()


}

Gin lets you specify which headers to hold the real client IP (if any), as well as specifying which proxies (or direct clients) you trust to specify one of these headers.

Use function SetTrustedProxies() on your gin.Engine to specify network addresses or network CIDRs from where clients which their request headers related to client IP can be trusted. They can be IPv4 addresses, IPv4 CIDRs, IPv6 addresses or IPv6 CIDRs.

Attention: Gin trust all proxies by default if you don't specify a trusted proxy using the function above, this is NOT safe. At the same time, if you don't use any proxy, you can disable this feature by using Engine.SetTrustedProxies(nil), then Context.ClientIP() will return the remote address directly to avoid some unnecessary computation.

import (
  "fmt"


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

func main() {

router := gin.Default()
  router.SetTrustedProxies([]string{"192.168.1.2"})

router.GET("/", func(c *gin.Context) {
    // If the client is 192.168.1.2, use the X-Forwarded-For
    // header to deduce the original client IP from the trust-
    // worthy parts of that header.
    // Otherwise, simply return the direct client IP
    fmt.Printf("ClientIP: %s\n", c.ClientIP())
  })
  router.Run()
}

Notice: If you are using a CDN service, you can set the Engine.TrustedPlatform to skip TrustedProxies check, it has a higher priority than TrustedProxies. Look at the example below:

import (
  "fmt"


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

func main() {

router := gin.Default()
  // Use predefined header gin.PlatformXXX
  router.TrustedPlatform = gin.PlatformGoogleAppEngine
  // Or set your own trusted request header for another trusted proxy service
  // Don't set it to any suspect request header, it's unsafe
  router.TrustedPlatform = "X-CDN-IP"

router.GET("/", func(c *gin.Context) {
    // If you set TrustedPlatform, ClientIP() will resolve the
    // corresponding header and return IP directly
    fmt.Printf("ClientIP: %s\n", c.ClientIP())
  })
  router.Run()
}

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

package main


import (
  "net/http"

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

func setupRouter() *gin.Engine {
  r := gin.Default()
  r.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "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(http.MethodGet, "/ping", nil)
  router.ServeHTTP(w, req)

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

Awesome project lists using Gin web framework.

• gorush: A push notification server written in Go.
• fnproject: The container native, cloud agnostic serverless platform.
• photoprism: Personal photo management powered by Go and Google TensorFlow.
• krakend: Ultra performant API Gateway with middlewares.
• picfit: An image resizing server written in Go.
• brigade: Event-based Scripting for Kubernetes.
• dkron: Distributed, fault tolerant job scheduling system.