Just in time to kick off the holiday season, Dwayne “The Rock” Johnson is bringing the spirit to 50,000 service men and women for the inaugural “Rock the Troops” event, which airs tonight on Spike.

The celeb-studded music and entertainment fest is hosted by Johnson, who has military and Navy SEALs in his family. The multi-hyphenate icon’s production company Seven Bucks Productions is behind the TV special with Johnson’s producing partner Dany Garcia, Casey Patterson Entertainment, Don Mischer Productions and Spike TV.

Honoring the 75th anniversary of Pearl Harbor, the event was shot on location at the Joint Base Pearl Harbor-Hickam in Hawaii, which became so flooded with audience members, the producers were overwhelmed with emotion.

“We never knew how many people would attend the event,” says Don Mischer. “No one bought tickets, you were just welcomed in when you showed your military pass. We were hoping for 12,000 to 15,000 military families. But by 2 p.m. in the afternoon, we were being told that people were lined up for blocks around the entrances…we were stunned.”

Producer Casey Patterson adds, “If anyone can do it and draw that kind of very passionate, enthusiastic crowd, it’s Dwayne.”

“Rock the Troops” was a passion project that was a seamless fit for both Patterson’s company, which specializes in live events and talent-centric programming like “Lip Sync Battle,” and Seven Bucks Productions — both entities that are known for “inspirational entertainment,” as Patterson puts it.

“When you have a message that’s very moving about doing the right thing and taking care of people, you need to do it as loud as possible,” says Garcia.

The base wasn’t just full of service men and women. Tons of celebs flocked to Hawaii to take part in the show, including Jack Black, Keegan Michael-Key, former Marine-turned actor Rob Riggle, Scott Eastwood, Terry Crews and Kevin Hart, who got ordained to marry a service couple during the event. George Clooney also makes an appearance via telecast, and performers include Nick Jonas, Flo Rida, Tenacious D, Lynyrd Skynyrd, Aaron Lewis and Elvis — well, in the form of Johnson. (See photo below.)

onstage during "Spike's Rock the Troops" event held at Joint Base Pearl Harbor - Hickam on October 22, 2016 in Honolulu, Hawaii. "Spike's Rock the Troops" will premiere on December 13 at 9 PM, ET/PT on Spike.

Patterson and Garcia say every single celebrity that was contacted to participate in the event was excited.

“Everyone that we mentioned it to, if they could physically be there, was so happy to do it and they showed up days before and in such great spirits. They spent real time with the families,” Patterson notes, specifically mentioning Matthew McConaughey, who was there for two days during rehearsal just hanging out with the military families.

“We really wanted this to feel like a Bob Hope-esque special like a rag-tag team of friends and buddies who would stand on their head and do anything to entertain these families,” Patterson says.

And they certainly did entertain. Garcia shares that at the end of the night, none of the celebs were in a rush to leave. “The talent was recognizing what they were doing and how important it was and they were having so much fun doing it backstage,” she says.

“Rock the Troops” took nearly two years before it got off the ground and was in development for ten months. For the actual event, the production staff was on-site in Hawaii for about ten days. “The base was so good to let us move all those fighter jets and we had to build 70-foot light towers throughout,” Patterson explains.

“The anticipation of doing a first-ever event, we were working day and night and running this live event,” Garcia says of the massive undertaking. “It was basically like doing five ‘SNL’ shows back to back to back. We were pulling from our WWE days when we were doing these live events.”

While the Pearl Harbor location is sentimental, the event wasn’t always set to take place at the base. Finding a location was a challenge, as the producers were looking overseas to “travel the show as far as we possibly could” and had found a more active military zone. But when the Paris attacks hit in November 2015, the production was asked to stay closer to home.

The base ended up being the perfect fit — not just for its symbolic nature to the military families, but also because of Johnson’s attachment to the island.

“I think anyone who knows his story knows that there came a crossroads in his life where he was getting into trouble and he had good people in his life who brought him into programs and into sports, and that happened in Hawaii. So to be standing with him in that moment, looking out at 50,000 people who showed up to this event on the other side of success was incredibly moving,” Patterson says.

“He was so moved. We were watching him and we knew that this was one of our largest moments in our production history. It was very special,” Garcia says. “It was a moment of humble gratitude to say we wanted to do this for you [the service men and women], and the audience responded.”

Adds Patterson: “He’s such a softy. He would kill me for saying that, but when he walked out and saw that amount of people for the first time, he started pounding his chest. He’s really doing that to try to keep it together.”

Johnson’s proximity was also crucial. The “Baywatch” star happened to be filming “Jumanji” in Hawaii at the same time, so he was able to use his star-power to spread the word.

“We knew that he would be there and we knew that we would be able to incorporate as many service men and women for possible,” Patterson says, adding that the base was the day-to-day partner in promoting the moral military event. “And then DJ was shooting ‘Jumanji’ on the other end of the island, so we had everyone cornered,” she adds.

Clearly, the turnout was better than expected. “It is what makes our business so fantastic — you carry high risk with just incredible reward,” Garcia says.

The producers hope to turn the event into an annual holiday tradition.

“I can’t speak for Spike. But we certainly launched this in a big way, hoping it would go on for years and years and years and become an event that our troops can count on,” Patterson says. Mischer adds: “It was a unique and memorable moment that will live on in this place that is so significant to the history of America.”

“Rock the Troops” airs tonight on Spike at 9 p.m. ET / 8 p.m. CT.