Roles of grandparents

What should the role of grandparents look like, particularly with disciplining/correcting? My husband and I have a young baby and have left her with our parents for date nights and short vacations. I worry though about when she gets older and stays with her grandparents while we're away and what corrections will look like. My parents want to be the fun grandparents and don't want to discipline grandchildren. They allow the grandkids to cheat in games, allow attitude problems, and give them whatever they want. My father-in-law on the other hand gets easily frustrated and will give consequences without pre-teaching based on his mood. The consequences are usually to go stand in the corner or sometimes spankings. Luckily my mother-in-law would be doing most of the watching and she is on board with TSG. She tried implementing TSG when her children were teenagers but she didn't have the support of her husband and wasn't consistent. I know I need to talk to them about our expectations but I am unsure of what to say.