The movie 'Rattlesnake' is not based on a true story. It's a work of imagination by the filmmakers to bring an engaging and thrilling narrative to the screen.
I haven't come across any reports stating that Jake Tapper is penning a novel. His focus seems to be on his journalistic endeavors, such as reporting the news, conducting interviews, and providing analysis. However, it's not impossible for him to venture into novel - writing in the future, but for now, there's no indication of it.