It's primarily a skill game, although luck plays a huge role. In any single given hand, luck is the predominant factor in who will win or lose. However, poker players don't play a single hand. They play hand after hand after hand & and overall, skill dominates.
After all poker is often played in a casino right alongside other games of chance like blackjack, craps and slot machines. But most people who play poker seriously know different though. Poker is 100% a game of skill in the long run. However there is a large element of luck in the short term.