get user login

func sendEmail(c *gin.Context) {
    claims := jwt.ExtractClaims(c)
    user, _ := c.Get(identityKey)
    ticker := time.NewTicker(24 * time.Hour)
    go func(ticker *time.Ticker) {
        for {
            select {
            case <-ticker.C:
                var certificateModel = new(certificateModels.CertificateModel)
                list, _ := certificateModel.GetExpiredDate()
                if list != nil{
                    authMail := smtp.PlainAuth("", "xxxxxx@gmail.com", xxxxxx", "smtp.gmail.com")
                    // Connect to the server, authenticate, set the sender and recipient,
                    // and send the email all in one step.
                    to := []string{user.(*User).UserName}
                    msg := []byte(
                        "To:"+user.(*User).UserName+"\r\n" +
                        "Subject: Expired Certificate Reminder!\r\n" +
                        "\r\n" +
                        "Anda memiliki sertifikat yang akan atau telah expired sebagai berikut : \r \n" +
                        "1. "+list[0].Name+"" +
                        "Silahkan diperbarui!.\r\n" ,
                    )
                    err := smtp.SendMail("smtp.gmail.com:587", authMail, "xxxxx@gmail.com", to, msg)
                    if err != nil {
                        log.Fatal(err)
                    }
                }
                //fmt.Printf("%v: Hello, World!\n")
            }
        }
    }(ticker)
}