Not familiar with pineapple beer.
I have a pineapple cider on tap currently. I wanted to experiment with a different flavor profile and what I normally make (apple/cinnamon or mixed berry).
I did my normal 5 gallons of apple juice + 2 pounds of table sugar fermented with Nottingham dry yeast. After cold crashing, racking to the keg and treating it with potassium sorbate, I back-sweetened with a couple cans of frozen pineapple juice concentrate and a cup of sugar. It's balanced, not sweet.
It's getting good reviews from friends who have tried it, although not the rave "gimme more, you ought to go into business making this" reviews the mixed berry cider always gets.