golang gorilla/session got nil value while checking session - go

Question

I have imported packages as
import (
"github.com/gorilla/sessions"
"github.com/gorilla/mux"
//CORS
"github.com/rs/cors"
"github.com/justinas/alice"
)
and defined store and main method as follow
var store = sessions.NewCookieStore([]byte("something-very-secret"))
const My_UI="http://localhost:3000"
func init() {
store.Options = &sessions.Options{
Path: "/",
MaxAge: 3600 * 1, // 1 hour
HttpOnly: true,
}
}
var router = mux.NewRouter() //MUX Handeler
//MAIN Function
func main() {
c := cors.New(cors.Options{
AllowedOrigins: []string{My_UI},
})
router.HandleFunc("/submitted",Login)
router.HandleFunc("/check",GetSession)
http.Handle("/", router)
chain := alice.New(c.Handler).Then(router) //CORS enable
fmt.Println("server started at port 8080")
http.ListenAndServe(":8080", chain)
}
In my method I’ve created and set session value as describe in gorilla doc
func Login(w http.ResponseWriter, r *http.Request) {
fmt.Println("In login----------->")
sess := GetCon() //get connection session
defer sess.Close() //close session
c := sess.DB("mydb").C("users") //collection-> select db table
session1, _ := store.Get(r, "loginSession") //login session
//parse json data
form := LoginUser{}
err := json.NewDecoder(r.Body).Decode(&form)
if err !=nil {
fmt.Println(err)
}
//get query data
var result []Person
errc1 := c.Find(bson.M{"email":form.Email,"password":form.Password}).All(&result)
if errc1 != nil {
js, err2 := json.Marshal("false")
if err2 != nil{return}
w.Header().Set("Content-Type", "application/json")
w.Write(js)
} else {
if len(result)==0 {
if err2 != nil {
return
}
w.Header().Set("Content-Type", "application/json")
w.Write(js)
} else {
fmt.Println("Success")
session1.Values["foo"] = "bar"
session1.Save(r, w)
fmt.Println("saved",session1)
js, err2 := json.Marshal(&result[0].Id)
if err2 != nil {return}
w.Header().Set("Content-Type", "application/json")
w.Write(js)
}
}
}
Now if i want to get this session value in another method i got nil every time. don't know what goes wrong in my code.
func GetSession(w http.ResponseWriter, r *http.Request) {
session1, _ := store.Get(r, "loginSession")
fmt.Println("Session in SessionHandler",session1)
if session.Values["foo"] == nil {
fmt.Println("not found",session.Values["foo"]))
} else {
fmt.Println("value",session.Values["foo"])
}
}

Answer 1

You got a mistake at your GetSession function. Please change session variable to session1
Also to check if session value is present better do it this way:
session, err := store.Get(r, ssid)
if err == nil {
if value, ok := session.Values["foo"].(string); ok {
session_data = value
}
}

Answer 2

I don't know what value you what to get, but I assume you want a string value. I wrote simple func GetFoo() to get string value from session1.Values["foo"].
Full example below:
package main
import (
"fmt"
"net/http"
"github.com/gorilla/mux"
"github.com/gorilla/sessions"
"github.com/justinas/alice"
"github.com/rs/cors"
)
var store = sessions.NewCookieStore([]byte("something-very-secret"))
const My_UI = "http://localhost:3000"
var router = mux.NewRouter() //MUX Handeler
//MAIN Function
func init() {
store.Options = &sessions.Options{
Path: "/",
MaxAge: 3600 * 1, // 1 hour
HttpOnly: true,
}
}
func main() {
c := cors.New(cors.Options{
AllowedOrigins: []string{My_UI},
})
router.HandleFunc("/login", Login)
router.HandleFunc("/check", GetSession)
http.Handle("/", router)
chain := alice.New(c.Handler).Then(router) //CORS enable
fmt.Println("server started at port 8080")
http.ListenAndServe(":8080", chain)
}
func GetFoo(f interface{}) string {
if f != nil {
if foo, ok := f.(string); ok {
return foo
}
}
return ""
}
func GetSession(w http.ResponseWriter, r *http.Request) {
session1, _ := store.Get(r, "loginSession")
foo := GetFoo(session1.Values["foo"])
if foo == "" {
fmt.Println("Foo is not set! Login to set value.")
} else {
fmt.Println("Foo Value:", foo, ".")
}
}
func Login(w http.ResponseWriter, r *http.Request) {
// Save Foo
session1, _ := store.Get(r, "loginSession")
session1.Values["foo"] = "bar"
session1.Save(r, w)
}