The Irish singer stars with Laura Michelle Kelly in the film, which sees an Australian housewife become a viral internet sensation when she records songs with her webcam.
"I was s**tting myself and my first day on set was with two kids in the scene with me," Keating told The Huffington Post. "So my first day on set and I'm dealing with kids but it went bloody brilliant. It was frightening but it was great. I'll never forget that day."
Keating added that he has been trying to break into acting for several years, saying: "I've been going to readings, auditions, and trying and it's been big stuff, like big directors and getting to the final five or six people and I've had representation in Los Angeles and the UK, but I guess one thing as well is someone taking the risk.
"You know, because it's not easy saying, 'This guy could be an actor, this singer'."
The 35-year-old confessed that he has no plans to walk away from music, but insisted that he is keen to further his acting career.
"By no means do I think I'm brilliant but I can act now where I couldn't do that before. I understand it, it's telling the truth, it's playing that character and being that character and not looking like you were acting," he explained.
"It was a long process to get there but I could walk into any role now, I'd be ready for anything. How I rate it, I couldn't tell you that."
> Ronan Keating: 'My debut movie Goddess is really cute'
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