Swift 3 Repeat Spawning of SKNode - swift

Question

I have a SKNode that spawns and moves across the screen. It all works as intended. I am, however, unsure how to make this occur multiple times. My desire is for the 'barrels' to spawn every 2 seconds. You can see my attempt in the code below.
class GameScene : SKScene, SKPhysicsContactDelegate {
var Player = SKSpriteNode()
var Ground = SKSpriteNode()
var Roof = SKSpriteNode()
var Background = SKSpriteNode()
let Obstacle1 = SKSpriteNode(imageNamed: "Fire Barrel 1")
override func didMove(to view: SKView) {
// Create Background Color
backgroundColor = bgColor
// Set World Gravity
self.physicsWorld.gravity = CGVector(dx: 0.0, dy: -4.0)
// Create Player
Player = SKSpriteNode(imageNamed: "Player")
Player.setScale(0.5)
Player.position = CGPoint(x: -self.frame.width / 2 + 100, y: -Player.frame.height / 2)
self.addChild(Player)
// Create Ground
Ground = SKSpriteNode(imageNamed: "BGTileBtm")
Ground.anchorPoint = CGPoint(x: 0,y: 0.5)
Ground.position = CGPoint(x: -self.frame.width / 2, y: -self.frame.height / 2)
self.addChild(Ground)
// Create Roof
Roof = SKSpriteNode(imageNamed: "BGTileTop")
Roof.anchorPoint = CGPoint(x: 1,y: 1)
Roof.position = CGPoint(x: -self.frame.width / 2, y: self.frame.height / 2 - Roof.frame.height)
Roof.zRotation = CGFloat(M_PI)
self.addChild(Roof)
// Set Physics Rules
Player.physicsBody = SKPhysicsBody(texture: SKTexture(imageNamed: "Player"), size: Player.size)
Player.physicsBody!.affectedByGravity = true
Player.physicsBody!.allowsRotation = false
Ground.physicsBody = SKPhysicsBody(texture: SKTexture(imageNamed: "Ground"), size: Ground.size)
Ground.physicsBody!.affectedByGravity = false
Ground.physicsBody!.isDynamic = false
// Obstacle
func addObstacle1(){
Obstacle1.position = CGPoint(x: self.frame.width / 2, y: -self.frame.height / 2 + Obstacle1.frame.height)
Obstacle1.zPosition = 1
addChild(Obstacle1)
let distance = CGVector(dx: -self.frame.width, dy: 0)
let moveDistance = SKAction.move(by: distance, duration: 5)
Obstacle1.run(moveDistance)
}
let spawnObstacles = SKAction(addObstacle1())
let delay = SKAction.wait(forDuration: 2)
let sequence = SKAction.sequence([delay, spawnObstacles])
run(SKAction.repeatForever(sequence))
}

Answer 1

Begin with putting the addObstacle outside of didMove method. Then put the following in your didMove method:
_ = Timer.scheduledTimer(timeInterval: 2, target: self, selector: #selector(addObstacle1), userInfo: nil, repeats: true)
It should repeat your addObstacle every two seconds :)