Get session values

Question

My rails app uses session for storing a user credentials for authorization. Trying to sign in and do some actions (that require a user session) in Go code. Should I retrieve a user session when signing in and pass to the next request? How can I handle that?

Answer 1

Go's standard library does not provide an HTTP session manager. So you have to write one yourself, or use one written by others.

Some examples:

• https://github.com/icza/session - includes Google App Engine support (disclosure: I'm the author)
• https://github.com/gorilla/sessions (part of the Gorilla web toolkit)

Usually HTTP sessions are managed via cookies between server and client, and as such, the session (session id) can be acquired directly from the request (http.Request) e.g. with Request.Cookie().

That being said it is not necessary to "pass" the session through the "request chain", every handler can access it just by having the http.Request.

For example using github.com/icza/session it can be done like this:

func MyHandler(w http.ResponseWriter, r *http.Request) {
    sess := session.Get(r)
    if sess == nil {
        // No session (yet)
    } else {
        // We have a session, use it
    }
}

Using Gorilla sessions, it's similar:

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

func MyHandler(w http.ResponseWriter, r *http.Request) {
    session, err := store.Get(r, "session-name")
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }
    // Use session
}