Those little bumps on the plant are called root knot nematode. They are cause by a little worm in the soil that lays its eggs on the potato.
Here is a close-up of one of the potatoes. The worst part about this bug is the way the potato feels. It still gives me the willies just thinking about it.
Root knot nematode is caused by planting infected plants into the soil. I suspect that I got it on the potato. I had planted a seed potato in a pot that I had got from a local nursery. A few days later I went out and the pot was empty. I asked my upstairs neighbor and he had dumped it out because he thought it was just an empty pot. He felt bad so he bought me some replacement potatoes. I planted one of those replacements in my pot and later found out he bought the potato from the store. This is why you should always get certified disease free seed potatoes from a nursery.
Now the potatoes are still fine to eat as long as you peel them (I made these guys into french fries). As for the soil, you need to treat it. If you have root knot nematode in a pot like I did you can either just get rid of the soil or cover it in plastic and leave it in the sun. The little nematodes die in the high temperatures so the soil should be good for next year. If you find this bug in your regular garden you either need to use some sort of insecticide to kill the bug or grow a nematode resistant plant there next year to allow the bug to die.
Good luck to everyone and enjoy the last few months or gardening.