Nicolas Cage plays the obligatory cop-about-to-retire in “211,” and you know what that means, right?

He’s in for a HAILSTORM OF GUNFIRE.

That’s hardly a spoiler alert. Has there ever been a movie about a cop who’s about to retire that features scenes of him bidding farewell to everyone at the station, clinking glasses at the sendoff party and then driving away with the spouse in the RV?

Movies starring Nic Cage are like haircuts: Every two months or so, you’re due for another one. “211” (as in “two-eleven,” as in police scanner terminology for a robbery) is Cage’s eighth film of 2017/2018, and with the exception of one brief and fantastically over-the-top meltdown scene, he delivers a disappointingly even-keeled performance in a film that is in dire need of ferocious overacting.

Anything to break through the mediocrity.

The opening scenes of “211” would lead one to believe we’re about to watch some sort of international thriller. When a smug arms dealer in a war-torn land stiffs a team of ex-military mercenaries, they gun him down — but before executing him, they get him to reveal the location of an American bank where he has secretly deposited a sizable chunk of cash.

Cut to Small Town, USA, where Office Mike Chandler (Cage), still mourning the loss of his wife to cancer, is going through the motions on his last days before retirement.

Mike’s partner is his son-in-law, Steve (Dwayne Cameron), who has just learned on this very morning his wife Lisa (Sophie Skelton), who is also Mike’s estranged daughter, is having their first baby.

Oh boy. You know what that means, right?

Mike’s in for a HAILSTORM OF GUNFIRE.

Mike and Steve are hosting a ride-along with a teenager named Kenny (Michael Rainey Jr.), who got into trouble for fighting back against school bullies. (This provides a clunky opportunity for some mild social commentary, given Kenny is an African-American teenager who is almost always filming on his phone, riding in the back seat of a police car with two white cops.)

Ori Pfeffer plays Tre, the leader of the small band of mercenaries (one of the henchmen is played by Cage’s son Weston) who outfit and arm themselves as if going to war before they storm a local bank holding “their” money. (The five gunmen talk about how the score could be as much as a million dollars, or $200,000 apiece. Geez. If the smug international arms dealer executing multi-zillion-dollar transactions had just paid them in the first place, he’d be alive today!)

While making a coffee stop, Mike and Steve notice a suspicious vehicle illegally parked in front of the bank — and that’s all it takes for the getaway driver to exit his vehicle and start firing away.

The rest of “211” is primarily about the extended shootouts between the local police and the heavily armed gunmen, with the body count piling up and the ridiculousness mounting.

Things really go off the rails after Steve sustains a potentially life-threatening gunshot wound. Lisa shows up at the hospital and bursts into the operating room where doctors and nurses are frantically working to save Steve.

Of course a doctor says, “Ma’am, you can’t be in here! Let us do our jobs!”

But Lisa retorts, “This is my husband! I’m not going anywhere.”

Um, what?

As it happens, Kenny’s mom is the chief surgeon, and when Mom’s phone rings, Lisa helpfully takes the phone out of her pocket and holds it up to Mom’s ear so Mom and Kenny can talk — while Mom is still IN THE OPERATING ROOM.

Meanwhile, poor Steve is in danger of flatlining. Hang up and get back to work, Mom!

We’re told “211” is based on the true story of the 1997 Battle of North Hollywood, when gunmen armed with illegal automatic weapons engaged in a bloody shootout with members of the LAPD, who had only pistols and revolvers.

But “211” is not set in Los Angeles nor does it take place in the 1990s. It’s just a muddled, overcrowded, trigger-happy heist movie brimming with clichés while constantly trying our patience.

★★

Momentum Pictures presents a film written and directed by York Shackleton. Rated R (for violence and language throughout). Running time: 86 minutes. Opens Friday at AMC Woodridge and on demand.