How to add a custom border to viewcontroller (ios) - ios

Question

I have a view (UIPopoverPresentation) which functionality works fine, but I need to add a custom border. I'm currently using a borderWidth and borderColor but I cannot seem to find a way to make a customized border, as seen in the photo below. How do I go about creating this customized border? Make a CGRect?
What I need:
What I have:
I've attempted to add an image to the background of the popover and it resulted in this:
EDIT: //PopOverView (presented using UIPopOverPresentation)
override func viewDidLoad() {
super.viewDidLoad()
self.view.layer.cornerRadius = 10.0
self.view.layer.borderWidth = 1.5
self.view.layer.borderColor = UIColor.whiteColor().CGColor
self.navigationController?.navigationBarHidden = true
self.popViewTableView.delegate = self
self.popViewTableView.dataSource = self
self.popViewTableView.alwaysBounceVertical = false
self.popViewTableView.backgroundColor = UIColor(red: 151.0/255.0, green: 87.0/255.0, blue: 172.0/255.0, alpha: 1.0)
}
//Base View Controller. When button is pressed, this function is called which presents the popover
func presentPopOver() {
let contentView = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("popViewController") as! DeckPopViewController
contentView.modalPresentationStyle = UIModalPresentationStyle.Popover
contentView.preferredContentSize = CGSizeMake(deckSelectionCGRect.width, 160)
let popoverMenuViewController = contentView.popoverPresentationController!
popoverMenuViewController.delegate = self
popoverMenuViewController.sourceView = view
popoverMenuViewController.permittedArrowDirections = UIPopoverArrowDirection(rawValue:0)
popoverMenuViewController.sourceRect = CGRectMake((self.view.bounds.width/2) - (deckSelectionCGRect.width/2), 120, deckSelectionCGRect.width, deckSelectionCGRect.height)
presentViewController(contentView, animated: true, completion: nil)
}
func adaptivePresentationStyleForPresentationController(controller: UIPresentationController) -> UIModalPresentationStyle {
return UIModalPresentationStyle.None
}
//ALSO: On the third image, I placed the border imageview over the entire view controller in the storyboard, set padding to zero on all sides (autolayout). It doesn't look good, though.