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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.
## 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)
- [Custom Log Format](#custom-log-format)
- [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 Uri](#bind-uri)
- [Bind HTML checkboxes](#bind-html-checkboxes)
- [Multipart/Urlencoded binding](#multiparturlencoded-binding)
- [XML, JSON, YAML and ProtoBuf rendering](#xml-json-yaml-and-protobuf-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)
- [Define format for the log of routes](#define-format-for-the-log-of-routes)
- [Set and get a cookie](#set-and-get-a-cookie)
- [Testing](#testing)
- [Users](#users)
## Installation
To install Gin, you'll first need to [install Go and set up your Go workspace](https://golang.org/doc/install).
### Installing with `go-get`
1. Download and install Gin:
```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 if you want to use constants such as `http.StatusOK`.
```go
import "net/http"
```
### Installing with [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@v1.3
```
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
```
## Requisites
For now, Gin will run on Go 1.6 or later. Using go 1.7 is highly recommended as it will become the minimum supported version soon.
To check the version of your Go installation, type in your Terminal emulator:
`$ go version`
## Quickstart project ("Ping, pong")
This example code responds "Pong" when a user `GET`s 0.0.0.0t:8080/ping.
To start, `cd` into your `$GOPATH/src` and create a new folder for your project.
After that, create a new file called `example.go` with the following contents:
```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
}
```
Save that file. In that same directory, run:
```
$ go run example.go
```
Now, open your favorite browser and go to `0.0.0.0:8080/ping`. If you see `Pong!`, congratulations! You have just finished your first Gin project.
## 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 uses `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).
`file.Filename` **SHOULD NOT** be trusted. See [`Content-Disposition` on MDN](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition#Directives) and [#1693](https://github.com/gin-gonic/gin/issues/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.
```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")
}
```
### Custom Log Format
```go
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(200, "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" "
```
### Model binding and validation
To bind a request body into a type, use model binding. We currently support binding of JSON, XML, YAML 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`, `BindYAML`
- **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`
- **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.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 (
//
// Using posts/index.tmpl
{{ end }} ``` templates/users/index.tmpl ```html {{ define "users/index.tmpl" }}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 have form } type StructZ struct { Z *StructZ `form:"name_z"` // HERE have 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(`