Go gin 框架 CORS

Question

我正在使用 Go gin 框架 gin

func CORSMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {
        c.Writer.Header().Set("Content-Type", "application/json")
        c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
        c.Writer.Header().Set("Access-Control-Max-Age", "86400")
        c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE, UPDATE")
        c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, X-Max")
        c.Writer.Header().Set("Access-Control-Allow-Credentials", "true")

        if c.Request.Method == "OPTIONS" {
            c.AbortWithStatus(200)
        } else {
            c.Next()
        }
    }
}

我得到了状态码：200 OK，但是在 OPTIONS 请求之后没有任何反应。 看起来我错过了什么，但我不明白我哪里错了。

有人可以帮助我吗？

Answer 1

我花了大约一个小时来了解为什么互联网上的某些示例有效，而有些则无效。所以我明白了 - 行顺序很重要，首先你应该使用配置然后声明你的端点，但不是相反的方式。

作品：

router := gin.Default()
router.Use(cors.Default())
router.GET("/ping", pong)
router.Run(":8082")

不起作用：

router := gin.Default()
router.GET("/ping", pong)
router.Use(cors.Default())
router.Run(":8082")

Answer 2

这对我有用 - 注意：直接设置标题。

func CORSMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {

        c.Header("Access-Control-Allow-Origin", "*")
        c.Header("Access-Control-Allow-Headers", "*")
        /*
            c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
            c.Writer.Header().Set("Access-Control-Allow-Credentials", "true")
            c.Writer.Header().Set("Access-Control-Allow-Headers", "access-control-allow-origin, access-control-allow-headers")
            c.Writer.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, DELETE, OPTIONS, PATCH")
        */

        if c.Request.Method == "OPTIONS" {
            c.AbortWithStatus(204)
            return
        }

        c.Next()
    }
}

Answer 3

func CORSMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {

        c.Header("Access-Control-Allow-Origin", "*")
        c.Header("Access-Control-Allow-Credentials", "true")
        c.Header("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
        c.Header("Access-Control-Allow-Methods", "POST,HEAD,PATCH, OPTIONS, GET, PUT")

        if c.Request.Method == "OPTIONS" {
            c.AbortWithStatus(204)
            return
        }

        c.Next()
    }
}

那就用吧

router = gin.New()  
router.Use(CORSMiddleware())

Answer 4

有包https://github.com/rs/cors，以正确的方式处理CORS请求。它具有流行路由器的示例，包括gin。那它：

package main

import (
    "net/http"

    "github.com/gin-gonic/gin"
    cors "github.com/rs/cors/wrapper/gin"
)

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

    router.Use(cors.Default())
    router.GET("/", func(context *gin.Context) {
        context.JSON(http.StatusOK, gin.H{"hello": "world"})
    })

    router.Run(":8080")
}

通常情况下，您只需将router.Use(cors.Default()) 的默认处理添加到gin 中的中间件。够了。

Answer 5

还有官方gin的处理CORS请求的中间件github.com/gin-contrib/cors。

您可以使用$ go get github.com/gin-contrib/cors 安装它，然后将这个中间件添加到您的应用程序中，如下所示： 主包

import (
    "time"

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

func main() {
    router := gin.Default()
    // CORS for https://foo.com and https://github.com origins, allowing:
    // - PUT and PATCH methods
    // - Origin header
    // - Credentials share
    // - Preflight requests cached for 12 hours
    router.Use(cors.New(cors.Config{
        AllowOrigins:     []string{"https://foo.com"},
        AllowMethods:     []string{"PUT", "PATCH"},
        AllowHeaders:     []string{"Origin"},
        ExposeHeaders:    []string{"Content-Length"},
        AllowCredentials: true,
        AllowOriginFunc: func(origin string) bool {
            return origin == "https://github.com"
        },
        MaxAge: 12 * time.Hour,
    }))
    router.Run()
}

Answer 6

我们创建了一个最小的中间件。

import (
    "github.com/gin-gonic/gin"
    "net/http"
)

type optionsMiddleware struct {

}

func CreateOptionsMiddleware() *optionsMiddleware{
    return &optionsMiddleware{}
}

func (middleware *optionsMiddleware)Response(context *gin.Context){
    if context.Request.Method == "OPTIONS" {
        context.AbortWithStatus(http.StatusNoContent)
    }
}

并将其注册到 gin 中间件：

app  := gin.New()
app.Use(middleware.CreateOptionsMiddleware().Response).
    Use(next-middleware)......

Answer 7

FWIW，这是我的 CORS 中间件，可以满足我的需求。

func CORSMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {
        c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
        c.Writer.Header().Set("Access-Control-Allow-Credentials", "true")
        c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
        c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET, PUT")

        if c.Request.Method == "OPTIONS" {
            c.AbortWithStatus(204)
            return
        }

        c.Next()
    }
}