How can i get my baby to sleep at night?

i'm after more personal advice to my situation, cos i know its a common question and i have read answers to these questions. My son is 4mths old, recently i have noticed a pattern of half hr naps in the day and one long one somewhere in the day, but he is not very good at sleeping at night. don't suggest a bath because he is not a huge fan of baths yet and gets more worked up having 1. people say keep him awake in the day but if he is moaning it isn't like you can just carry on playing and he will snap out of it. He goes down at bedtime, with help of dummy, but only sleep for about 2hrs is the best, i will try getting him back to sleep, used to lift him out of cot, now try to leave him in cot. i might give a feed, i keep it all dark and usually his eyes stay shut so he might go down fairly easily after his feed but say hr later his unsettled again. I know there is no easy fix but if anyone has had similar experience or some advice cheers.