# Gin Web Framework [![Build Status](https://travis-ci.org/gin-gonic/gin.svg)](https://travis-ci.org/gin-gonic/gin) [![codecov](https://codecov.io/gh/gin-gonic/gin/branch/master/graph/badge.svg)](https://codecov.io/gh/gin-gonic/gin) [![Go Report Card](https://goreportcard.com/badge/github.com/gin-gonic/gin)](https://goreportcard.com/report/github.com/gin-gonic/gin) [![GoDoc](https://godoc.org/github.com/gin-gonic/gin?status.svg)](https://godoc.org/github.com/gin-gonic/gin) [![Join the chat at https://gitter.im/gin-gonic/gin](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/gin-gonic/gin?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Sourcegraph](https://sourcegraph.com/github.com/gin-gonic/gin/-/badge.svg)](https://sourcegraph.com/github.com/gin-gonic/gin?badge) [![Open Source Helpers](https://www.codetriage.com/gin-gonic/gin/badges/users.svg)](https://www.codetriage.com/gin-gonic/gin) 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](https://github.com/julienschmidt/httprouter). If you need performance and good productivity, you will love Gin. ![Gin console logger](https://gin-gonic.github.io/gin/other/console.png) ## Contents - [Installation](#installation) - [Prerequisite](#prerequisite) - [Quick start](#quick-start) - [Benchmarks](#benchmarks) - [Gin v1.stable](#gin-v1-stable) - [Build with jsoniter](#build-with-jsoniter) - [API Examples](#api-examples) - [Using GET,POST,PUT,PATCH,DELETE and OPTIONS](#using-get-post-put-patch-delete-and-options) - [Parameters in path](#parameters-in-path) - [Querystring parameters](#querystring-parameters) - [Multipart/Urlencoded Form](#multiparturlencoded-form) - [Another example: query + post form](#another-example-query--post-form) - [Map as querystring or postform parameters](#map-as-querystring-or-postform-parameters) - [Upload files](#upload-files) - [Grouping routes](#grouping-routes) - [Blank Gin without middleware by default](#blank-gin-without-middleware-by-default) - [Using middleware](#using-middleware) - [How to write log file](#how-to-write-log-file) - [Model binding and validation](#model-binding-and-validation) - [Custom Validators](#custom-validators) - [Only Bind Query String](#only-bind-query-string) - [Bind Query String or Post Data](#bind-query-string-or-post-data) - [Bind HTML checkboxes](#bind-html-checkboxes) - [Multipart/Urlencoded binding](#multiparturlencoded-binding) - [XML, JSON and YAML rendering](#xml-json-and-yaml-rendering) - [JSONP rendering](#jsonp) - [Serving static files](#serving-static-files) - [Serving data from reader](#serving-data-from-reader) - [HTML rendering](#html-rendering) - [Multitemplate](#multitemplate) - [Redirects](#redirects) - [Custom Middleware](#custom-middleware) - [Using BasicAuth() middleware](#using-basicauth-middleware) - [Goroutines inside a middleware](#goroutines-inside-a-middleware) - [Custom HTTP configuration](#custom-http-configuration) - [Support Let's Encrypt](#support-lets-encrypt) - [Run multiple service using Gin](#run-multiple-service-using-gin) - [Graceful restart or stop](#graceful-restart-or-stop) - [Build a single binary with templates](#build-a-single-binary-with-templates) - [Bind form-data request with custom struct](#bind-form-data-request-with-custom-struct) - [Try to bind body into different structs](#try-to-bind-body-into-different-structs) - [http2 server push](#http2-server-push) - [Testing](#testing) - [Users](#users--) ## Installation To install Gin package, you need to install Go and set your Go workspace first. 1. Download and install it: ```sh $ go get -u github.com/gin-gonic/gin ``` 2. Import it in your code: ```go import "github.com/gin-gonic/gin" ``` 3. (Optional) Import `net/http`. This is required for example if using constants such as `http.StatusOK`. ```go import "net/http" ``` ### Use a vendor tool like [Govendor](https://github.com/kardianos/govendor) 1. `go get` govendor ```sh $ go get github.com/kardianos/govendor ``` 2. Create your project folder and `cd` inside ```sh $ mkdir -p $GOPATH/src/github.com/myusername/project && cd "$_" ``` 3. Vendor init your project and add gin ```sh $ govendor init $ govendor fetch github.com/gin-gonic/gin@v1.2 ``` 4. Copy a starting template inside your project ```sh $ curl https://raw.githubusercontent.com/gin-gonic/gin/master/examples/basic/main.go > main.go ``` 5. Run your project ```sh $ go run main.go ``` ## Prerequisite Now Gin requires Go 1.6 or later and Go 1.7 will be required soon. ## Quick start ```sh # assume the following codes in example.go file $ cat example.go ``` ```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](https://github.com/julienschmidt/httprouter) [See all benchmarks](/BENCHMARKS.md) 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 - [x] Zero allocation router. - [x] Still the fastest http router and framework. From routing to writing. - [x] Complete suite of unit tests - [x] Battle tested - [x] API frozen, new releases will not break your code. ## Build with [jsoniter](https://github.com/json-iterator/go) Gin use `encoding/json` as default json package but you can change to [jsoniter](https://github.com/json-iterator/go) by build from other tags. ```sh $ go build -tags=jsoniter . ``` ## API Examples ### Using GET, POST, PUT, PATCH, DELETE and OPTIONS ```go 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 ```go 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) }) router.Run(":8080") } ``` ### Querystring parameters ```go 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 ```go 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 ``` ```go 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 ``` ### Map as querystring or postform parameters ``` POST /post?ids[a]=1234&ids[b]=hello HTTP/1.1 Content-Type: application/x-www-form-urlencoded names[first]=thinkerou&names[second]=tianou ``` ```go 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] ``` ### Upload files #### Single file References issue [#774](https://github.com/gin-gonic/gin/issues/774) and detail [example code](examples/upload-file/single). ```go 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`: ```bash 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](examples/upload-file/multiple). ```go 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`: ```bash 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 ```go 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 ```go r := gin.New() ``` instead of ```go // Default With the Logger and Recovery middleware already attached r := gin.Default() ``` ### Using middleware ```go 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") testing.GET("/analytics", analyticsEndpoint) } // Listen and serve on 0.0.0.0:8080 r.Run(":8080") } ``` ### How to write log file ```go 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(200, "pong") })    router.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**](https://github.com/go-playground/validator) for validation. Check the full docs on tags usage [here](http://godoc.org/gopkg.in/go-playground/validator.v8#hdr-Baked_In_Validators_and_Tags). 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` - **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` - **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. ```go // 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.ShouldBindXML(&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 ( // // // user // 123 // ) 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** ```shell $ 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. ### Custom Validators It is also possible to register custom validators. See the [example code](examples/custom-validation/server.go). [embedmd]:# (examples/custom-validation/server.go go) ```go 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()}) } } ``` ```console $ 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](https://github.com/go-playground/validator/releases/tag/v8.7) can also be registered this way. See the [struct-lvl-validation example](examples/struct-lvl-validations) to learn more. ### Only Bind Query String `ShouldBindQuery` function only binds the query params and not the post data. See the [detail information](https://github.com/gin-gonic/gin/issues/742#issuecomment-315953017). ```go 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](https://github.com/gin-gonic/gin/issues/742#issuecomment-264681292). ```go 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: ```sh $ curl -X GET "localhost:8085/testing?name=appleboy&address=xyz&birthday=1992-03-15" ``` ### Bind HTML checkboxes See the [detail information](https://github.com/gin-gonic/gin/issues/129#issuecomment-124260092) main.go ```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 ```html

Check some colors

``` result: ``` {"color":["red","green","blue"]} ``` ### Multipart/Urlencoded binding ```go 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: ```sh $ curl -v --form user=user --form password=password http://localhost:8080/login ``` ### XML, JSON and YAML rendering ```go 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. ```go 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. ```go 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. ```go func main() { r := gin.Default() r.GET("/someJSON", func(c *gin.Context) { data := map[string]interface{}{ "lang": "GO语言", "tag": "
", } // 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 ```go 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 ```go 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() ```go 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

{{ .title }}

``` Using templates with same name in different directories ```go 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 ```html {{ define "posts/index.tmpl" }}

{{ .title }}

Using posts/index.tmpl

{{ end }} ``` templates/users/index.tmpl ```html {{ define "users/index.tmpl" }}

{{ .title }}

Using users/index.tmpl

{{ end }} ``` #### Custom Template renderer You can also use your own html template render ```go 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 ```go r := gin.Default() r.Delims("{[{", "}]}") r.LoadHTMLGlob("/path/to/templates")) ``` #### Custom Template Funcs See the detail [example code](examples/template). main.go ```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", map[string]interface{}{ "now": time.Date(2017, 07, 01, 0, 0, 0, 0, time.UTC), }) }) router.Run(":8080") } ``` raw.tmpl ```html Date: {[{.now | formatAsDate}]} ``` Result: ``` Date: 2017/07/01 ``` ### Multitemplate Gin allow by default use only one html.Template. Check [a multitemplate render](https://github.com/gin-contrib/multitemplate) for using features like go 1.6 `block template`. ### Redirects Issuing a HTTP redirect is easy. Both internal and external locations are supported. ```go r.GET("/test", func(c *gin.Context) { c.Redirect(http.StatusMovedPermanently, "http://www.google.com/") }) ``` Issuing a Router redirect, use `HandleContext` like below. ``` go 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 ```go 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 ```go // 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. ```go 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: ```go func main() { router := gin.Default() http.ListenAndServe(":8080", router) } ``` or ```go 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. [embedmd]:# (examples/auto-tls/example1/main.go go) ```go 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. [embedmd]:# (examples/auto-tls/example2/main.go go) ```go 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](https://github.com/gin-gonic/gin/issues/346) and try the following example: [embedmd]:# (examples/multiple-service/main.go go) ```go 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](https://github.com/fvbock/endless) to replace the default `ListenAndServe`. Refer issue [#296](https://github.com/gin-gonic/gin/issues/296) for more details. ```go router := gin.Default() router.GET("/", handler) // [...] endless.ListenAndServe(":4242", router) ``` An alternative to endless: * [manners](https://github.com/braintree/manners): A polite Go HTTP server that shuts down gracefully. * [graceful](https://github.com/tylerb/graceful): Graceful is a Go package enabling graceful shutdown of an http.Handler server. * [grace](https://github.com/facebookgo/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()](https://golang.org/pkg/net/http/#Server.Shutdown) method for graceful shutdowns. See the full [graceful-shutdown](./examples/graceful-shutdown) example with gin. [embedmd]:# (examples/graceful-shutdown/graceful-shutdown/server.go go) ```go // +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][]. [go-assets]: https://github.com/jessevdk/go-assets ```go 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: ```go 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: ```go 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. ```go 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`. ```go 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](https://github.com/gin-gonic/gin/pull/1341)). ### http2 server push http.Pusher is supported only **go1.8+**. See the [golang blog](https://blog.golang.org/h2push) for detail information. [embedmd]:# (examples/http-pusher/main.go go) ```go package main import ( "html/template" "log" "github.com/gin-gonic/gin" ) var html = template.Must(template.New("https").Parse(` Https Test

Welcome, Ginner!

`)) 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. ```go 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: ```go 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 Awesome project lists using [Gin](https://github.com/gin-gonic/gin) web framework. * [drone](https://github.com/drone/drone): Drone is a Continuous Delivery platform built on Docker, written in Go * [gorush](https://github.com/appleboy/gorush): A push notification server written in Go.