Las variables de sesión no se mantienen a través de la solicitud mientras se usa el kit de herramientas web de sesiones de gorilla. Cuando inicio el servidor y escribo localhost: 8100 / page se dirige a login.html ya que los valores de sesión no existen. Después de iniciar sesión, configuro la variable de sesión en la tienda y la página se redirige a home.html. Pero cuando abro una nueva pestaña y escribo localhost: 8100 / la página debe dirigirse a home.html usando variables de sesión ya almacenadas, pero la página se redirige a login.html. El siguiente es el código.

    package main

import (
    "crypto/md5"
    "encoding/hex"
    "fmt"
    "github.com/gocql/gocql"
    "github.com/gorilla/mux"
    "github.com/gorilla/sessions"
    "net/http"
    "time"
)

var store = sessions.NewCookieStore([]byte("something-very-secret"))

var router = mux.NewRouter()

func init() {

    store.Options = &sessions.Options{
        Domain:   "localhost",
        Path:     "/",
        MaxAge:   3600 * 1, // 1 hour
        HttpOnly: true,
    }
}
func main() {
    //session handling
    router.HandleFunc("/", SessionHandler)
    router.HandleFunc("/signIn", SignInHandler)
    router.HandleFunc("/signUp", SignUpHandler)
    router.HandleFunc("/logOut", LogOutHandler)
    http.Handle("/", router)
    http.ListenAndServe(":8100", nil)
}

//handler for signIn
func SignInHandler(res http.ResponseWriter, req *http.Request) {

    email := req.FormValue("email")
    password := req.FormValue("password")

    //Generate hash of password
    hasher := md5.New()
    hasher.Write([]byte(password))
    encrypted_password := hex.EncodeToString(hasher.Sum(nil))

    //cassandra connection
    cluster := gocql.NewCluster("localhost")
    cluster.Keyspace = "gbuy"
    cluster.DefaultPort = 9042
    cluster.Consistency = gocql.Quorum
    session, _ := cluster.CreateSession()
    defer session.Close()

    //select query
    var firstname string
    stmt := "SELECT firstname FROM USER WHERE email= '" + email + "' and password ='" + encrypted_password + "';"
    err := session.Query(stmt).Scan(&firstname)
    if err != nil {
        fmt.Fprintf(res, "failed")
    } else {
        if firstname == "" {
            fmt.Fprintf(res, "failed")
        } else {
            fmt.Fprintf(res, firstname)
        }
    }

    //store in session variable
    sessionNew, _ := store.Get(req, "loginSession")

    // Set some session values.
    sessionNew.Values["email"] = email
    sessionNew.Values["name"] = firstname

    // Save it.
    sessionNew.Save(req, res)
    //store.Save(req,res,sessionNew)

    fmt.Println("Session after logging:")
    fmt.Println(sessionNew)

}

//handler for signUp
func SignUpHandler(res http.ResponseWriter, req *http.Request) {

    fName := req.FormValue("fName")
    lName := req.FormValue("lName")
    email := req.FormValue("email")
    password := req.FormValue("passwd")
    birthdate := req.FormValue("date")
    city := req.FormValue("city")
    gender := req.FormValue("gender")

    //Get current timestamp and format it.
    sysdate := time.Now().Format("2006-01-02 15:04:05-0700")

    //Generate hash of password
    hasher := md5.New()
    hasher.Write([]byte(password))
    encrypted_password := hex.EncodeToString(hasher.Sum(nil))

    //cassandra connection
    cluster := gocql.NewCluster("localhost")
    cluster.Keyspace = "gbuy"
    cluster.DefaultPort = 9042
    cluster.Consistency = gocql.Quorum
    session, _ := cluster.CreateSession()
    defer session.Close()

    //Insert the data into the Table
    stmt := "INSERT INTO USER (email,firstname,lastname,birthdate,city,gender,password,creation_date) VALUES ('" + email + "','" + fName + "','" + lName + "','" + birthdate + "','" + city + "','" + gender + "','" + encrypted_password + "','" + sysdate + "');"
    fmt.Println(stmt)
    err := session.Query(stmt).Exec()
    if err != nil {
        fmt.Fprintf(res, "failed")
    } else {
        fmt.Fprintf(res, fName)
    }
}

//handler for logOut
func LogOutHandler(res http.ResponseWriter, req *http.Request) {
    sessionOld, err := store.Get(req, "loginSession")

    fmt.Println("Session in logout")
    fmt.Println(sessionOld)
    if err = sessionOld.Save(req, res); err != nil {
        fmt.Println("Error saving session: %v", err)
    }
}

//handler for Session
func SessionHandler(res http.ResponseWriter, req *http.Request) {

    router.PathPrefix("/").Handler(http.FileServer(http.Dir("../static/")))
    session, _ := store.Get(req, "loginSession")

    fmt.Println("Session in SessionHandler")
    fmt.Println(session)


    if val, ok := session.Values["email"].(string); ok {
        // if val is a string
        switch val {
        case "": {
            http.Redirect(res, req, "html/login.html", http.StatusFound) }
        default:
            http.Redirect(res, req, "html/home.html", http.StatusFound)
        }
    } else {
        // if val is not a string type
        http.Redirect(res, req, "html/login.html", http.StatusFound)
    }
}

¿Alguien puede decirme qué estoy haciendo mal? Gracias por adelantado.