Gin: grouping routes and middleware not working

[rasheedhamdawi]

I am trying to add this middleware

func CORS () gin.HandlerFunc {
    return func(context *gin.Context) {
        context.Writer.Header().Add("Access-Control-Allow-Origin", "*")
        context.Writer.Header().Set("Access-Control-Max-Age", "86400")
        context.Writer.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE, UPDATE")
        context.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
        context.Writer.Header().Set("Access-Control-Expose-Headers", "Content-Length")
        context.Writer.Header().Set("Access-Control-Allow-Credentials", "true")

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

but not work with grouping routes

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

    // cors middleware not working
    users := router.Group("/users")
    users.GET("/", Users)

    // cors middleware not working
    users := router.Group("/users")
    users.Use(CORS())
    users.GET("/", Users)

    // cors middleware working fine
    router.GET("/users")

    router.Run(":3000")
  }

[Norbell]

Interesting. I used the following main-function and everything works fine.

What part of your code is not working?

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

    users := router.Group("/users")
    users.GET("/", Users)

    router.Run(":3000")
  }

[douglarek]

@rasheedhamdawi is this resolved ? anything share ?

[sonemaro]

@douglarek I had exactly this problem. You should define your middlewares before your grouping route(maybe right after creating the router instance)

[da2018]

Same issue, and you should put your middleware before the routes, like this, and it works.

    r := gin.Default()
    r.Use(Authentication())
    r.POST("/v2/create", handlers.CreateHandler)

[sonemaro]

And here it is what I'm using:

transaction := api.Group("/transaction", HandleApiKey())

transaction.GET("/", func(c *gin.Context) {
    //a nice logic will be here
})

func HandleApiKey() gin.HandlerFunc {
    return func(c *gin.Context) {
    //another nice middleware will be here
    }
}

[jmwohl]

Why is this closed? As far as I can tell, this is still an issue. Or are we not meant to use middleware on router groups?

[sonemaro]

@jmwohl Can I see the code you are using? Have you defined the middleware before the group route?

[John-Ciuchea]

If I define your route like this users.GET("/", Users) in api call you I added a leading slash fetch("http://localhost:3000/users/")

I defined the route without leading slash users.GET("", Users) then I get a cors error when I add the leading slash in api request.

I don't think that cors should have anything to do with leading slashes.

[liuggio]

This is an issue!
Is impossible to add middleware to Groups

[liuggio]

Found the problem it's related to gin-contrib/Cors is mandatory to add the options route on subgroup