This is a swift port of the official FacebookSDK login tutorial. It's been tested on Xcode 6 Beta 1 with the iOS 8 Simulator. You can find the official FB tutorial here: https://developers.facebook.com/docs/facebook-login/ios/v2.0

FBLogin.swift

// YourProject-Bridging-Header.h
#import <FacebookSDK/FacebookSDK.h>


// AppDelegate.swift
import UIKit
 
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    .
    .
    .
    func application(application: UIApplication, openURL url: NSURL, sourceApplication: NSString?, annotation: AnyObject) -> Bool {
        var wasHandled:Bool = FBAppCall.handleOpenURL(url, sourceApplication: sourceApplication)
        return wasHandled
    }
 
}

// ViewController.swift
import Foundation
import UIKit

class LoginViewController: UIViewController, FBLoginViewDelegate {
    
    var fbl: FBLoginView = FBLoginView()
    
    @IBOutlet var loginView : FBLoginView
    @IBOutlet var profilePictureView : FBProfilePictureView
    @IBOutlet var userNameTxt : UILabel
    @IBOutlet var logStatusTxt : UILabel
    
    override func viewDidLoad() {
        super.viewDidLoad()
        fbl.delegate = self
        loginView.readPermissions = ["public_profile", "email", "user_friends"]
        // Do any additional setup after loading the view, typically from a nib.
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func loginViewShowingLoggedInUser(loginView: FBLoginView) {
        logStatusTxt.text = "You are logged in!"
    }
    
    func loginViewFetchedUserInfo(loginView: FBLoginView?, user: FBGraphUser) {
            profilePictureView.profileID = user.objectID
            userNameTxt.text = user.first_name + " " + user.last_name
    }
    
    func loginViewShowingLoggedOutUser(loginView: FBLoginView?) {
        profilePictureView.profileID = nil
        userNameTxt.text = ""
        logStatusTxt.text = "You are logged out!"
    }
}

It works on beta 4!