422 lines
8.8 KiB
Markdown
422 lines
8.8 KiB
Markdown
#Gin Web Framework
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[](https://godoc.org/github.com/gin-gonic/gin)
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[](https://travis-ci.org/gin-gonic/gin)
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Gin is a web framework written in Golang. It features a martini-like API with much better performance, up to 40 times faster. If you need performance and good productivity, you will love Gin.
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##Gin is new, will it be supported?
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Yes, Gin is an internal project of [my](https://github.com/manucorporat) upcoming startup. We developed it and we are going to continue using and improve it.
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##Roadmap for v0.2
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- Performance improments, reduce allocation and garbage collection overhead
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- Fix bugs
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- Ask our designer for a cool logo
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- Add tons of unit tests and benchmarks
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- Improve logging system
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- Improve JSON/XML validation using bindings
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- Improve XML support
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- Improve documentation
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- Add more cool middlewares, for example redis catching (this also helps developers to understand the framework)
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- Continuous integration
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## Start using it
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Obviously, you need to have Git and Go! already installed to run Gin.
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Run this in your terminal
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```
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go get github.com/gin-gonic/gin
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```
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Then import it in your Go! code:
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```
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import "github.com/gin-gonic/gin"
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```
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##API Examples
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#### Create most basic PING/PONG HTTP endpoint
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```go
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package main
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import "github.com/gin-gonic/gin"
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func main() {
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r := gin.Default()
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r.GET("/ping", func(c *gin.Context) {
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c.String(200, "pong")
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Using GET, POST, PUT, PATCH, DELETE and OPTIONS
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```go
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func main() {
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// Creates a gin router + logger and recovery (crash-free) middlewares
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r := gin.Default()
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r.GET("/someGet", getting)
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r.POST("/somePost", posting)
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r.PUT("/somePut", putting)
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r.DELETE("/someDelete", deleting)
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r.PATCH("/somePatch", patching)
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r.HEAD("/someHead", head)
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r.OPTIONS("/someOptions", options)
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Parameters in path
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```go
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func main() {
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r := gin.Default()
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r.GET("/user/:name", func(c *gin.Context) {
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name := c.Params.ByName("name")
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message := "Hello "+name
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c.String(200, message)
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})
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r.GET("/user/:name/:action", func(c *gin.Context) {
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name := c.Params.ByName("name")
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action := c.Params.ByName("action")
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message := name + " is " + action
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c.String(200, message)
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Grouping routes
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```go
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func main() {
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r := gin.Default()
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// Simple group: v1
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v1 := r.Group("/v1")
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{
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v1.POST("/login", loginEndpoint)
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v1.POST("/submit", submitEndpoint)
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v1.POST("/read", readEndpoint)
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}
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// Simple group: v2
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v2 := r.Group("/v2")
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{
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v2.POST("/login", loginEndpoint)
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v2.POST("/submit", submitEndpoint)
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v2.POST("/read", readEndpoint)
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}
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Blank Gin without middlewares by default
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Use
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```go
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r := gin.New()
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```
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instead of
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```go
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r := gin.Default()
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```
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#### Using middlewares
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```go
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func main() {
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// Creates a router without any middleware by default
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r := gin.New()
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// Global middlewares
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r.Use(gin.Logger())
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r.Use(gin.Recovery())
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// Per route middlewares, you can add as many as you desire.
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r.GET("/benchmark", MyBenchLogger(), benchEndpoint)
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// Authorization group
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// authorized := r.Group("/", AuthRequired())
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// exactly the same than:
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authorized := r.Group("/")
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// per group middlewares! in this case we use the custom created
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// AuthRequired() middleware just in the "authorized" group.
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authorized.Use(AuthRequired())
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{
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authorized.POST("/login", loginEndpoint)
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authorized.POST("/submit", submitEndpoint)
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authorized.POST("/read", readEndpoint)
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// nested group
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testing := authorized.Group("testing")
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testing.GET("/analytics", analyticsEndpoint)
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}
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### JSON parsing and validation
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```go
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type LoginJSON struct {
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User string `json:"user" binding:"required"`
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Password string `json:"password" binding:"required"`
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}
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func main() {
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r := gin.Default()
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r.POST("/login", func(c *gin.Context) {
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var json LoginJSON
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// If EnsureBody returns false, it will write automatically the error
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// in the HTTP stream and return a 400 error. If you want custom error
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// handling you should use: c.ParseBody(interface{}) error
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if c.EnsureBody(&json) {
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if json.User == "manu" && json.Password == "123" {
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c.JSON(200, gin.H{"status": "you are logged in"})
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} else {
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c.JSON(401, gin.H{"status": "unauthorized"})
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}
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}
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### XML, and JSON rendering
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```go
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func main() {
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r := gin.Default()
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// gin.H is a shortcup for map[string]interface{}
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r.GET("/someJSON", func(c *gin.Context) {
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c.JSON(200, gin.H{"message": "hey", "status": 200})
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})
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r.GET("/moreJSON", func(c *gin.Context) {
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// You also can use a struct
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var msg struct {
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Name string `json:"user"`
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Message string
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Number int
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}
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msg.Name = "Lena"
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msg.Message = "hey"
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msg.Number = 123
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// Note that msg.Name becomes "user" in the JSON
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// Will output : {"user": "Lena", "Message": "hey", "Number": 123}
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c.JSON(200, msg)
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})
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r.GET("/someXML", func(c *gin.Context) {
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c.XML(200, gin.H{"message": "hey", "status": 200})
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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####HTML rendering
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Using LoadHTMLTemplates()
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```go
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func main() {
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r := gin.Default()
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r.LoadHTMLTemplates("templates/*")
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r.GET("/index", func(c *gin.Context) {
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obj := gin.H{"title": "Main website"}
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c.HTML(200, "index.tmpl", obj)
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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You can also use your own html template render
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```go
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import "html/template"
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func main() {
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r := gin.Default()
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html := template.Must(template.ParseFiles("file1", "file2"))
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r.HTMLTemplates = html
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Custom Middlewares
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```go
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func Logger() gin.HandlerFunc {
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return func(c *gin.Context) {
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t := time.Now()
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// Set example variable
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c.Set("example", "12345")
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// before request
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c.Next()
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// after request
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latency := time.Since(t)
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log.Print(latency)
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// access the status we are sending
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status := c.Writer.Status()
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log.Println(status)
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}
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}
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func main() {
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r := gin.New()
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r.Use(Logger())
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r.GET("/test", func(c *gin.Context) {
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example := r.Get("example").(string)
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// it would print: "12345"
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log.Println(example)
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Using BasicAuth() middleware
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```go
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// similate some private data
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var secrets = gin.H{
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"foo": gin.H{"email": "foo@bar.com", "phone": "123433"},
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"austin": gin.H{"email": "austin@example.com", "phone": "666"},
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"lena": gin.H{"email": "lena@guapa.com", "phone": "523443"},
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}
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func main() {
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r := gin.Default()
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// Group using gin.BasicAuth() middleware
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// gin.Accounts is a shortcut for map[string]string
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authorized := r.Group("/admin", gin.BasicAuth(gin.Accounts{
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"foo": "bar",
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"austin": "1234",
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"lena": "hello2",
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"manu": "4321",
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}))
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// /admin/secrets endpoint
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// hit "localhost:8080/admin/secrets
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authorized.GET("/secrets", func(c *gin.Context) {
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// get user, it was setted by the BasicAuth middleware
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user := c.Get(gin.AuthUserKey).(string)
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if secret, ok := secrets[user]; ok {
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c.JSON(200, gin.H{"user": user, "secret": secret})
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} else {
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c.JSON(200, gin.H{"user": user, "secret": "NO SECRET :("})
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}
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Goroutines inside a middleware
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When starting inside a middleware or handler, you **SHOULD NOT** use the original context inside it, you have to use a read-only copy.
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```go
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func main() {
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r := gin.Default()
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r.GET("/long_async", func(c *gin.Context) {
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// create copy to be used inside the goroutine
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c_cp := c.Copy()
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go func() {
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// simulate a long task with time.Sleep(). 5 seconds
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time.Sleep(5 * time.Second)
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// note than you are using the copied context "c_cp", IMPORTANT
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log.Println("Done! in path " + c_cp.Req.URL.Path)
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}()
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})
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r.GET("/long_sync", func(c *gin.Context) {
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// simulate a long task with time.Sleep(). 5 seconds
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time.Sleep(5 * time.Second)
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// since we are NOT using a goroutine, we do not have to copy the context
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log.Println("Done! in path " + c.Req.URL.Path)
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})
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// Listen and server on 0.0.0.0:8080
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r.Run(":8080")
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}
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```
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#### Custom HTTP configuration
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Use `http.ListenAndServe()` directly, like this:
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```go
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func main() {
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router := gin.Default()
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http.ListenAndServe(":8080", router)
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}
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```
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or
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```go
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func main() {
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router := gin.Default()
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s := &http.Server{
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Addr: ":8080",
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Handler: router,
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ReadTimeout: 10 * time.Second,
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WriteTimeout: 10 * time.Second,
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MaxHeaderBytes: 1 << 20,
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}
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s.ListenAndServe()
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}
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```
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