Douglas Harper's Etymology Dictionary
"life at ease," expression popularized by 1917, American English, sometimes said to trace to various songs from c.1902.
Wiktionary
n. (context idiomatic dated English) An ideal life of carefree prosperity and luxurious contentment.
Wikipedia
Life of Riley is a British comedy television series, shown on BBC One and BBC HD. The show stars Caroline Quentin and Neil Dudgeon, who are recently married, and is set around their dysfunctional family. The show also features the couple's four children, Danny (Taylor Fawcett), Katy ( Lucinda Dryzek), Ted (Patrick Nolan), and Rosie (Ava and Neve Lamb). After three series it was confirmed that the show had been cancelled.
Life of Riley is a 2010 play by Alan Ayckbourn. It is set over a period over the seven months that a man called George Riley is diagnosed with a terminal illness, although George Riley does not appear in the play himself and is only ever referred to by the six onstage characters.
This play is the only Ayckbourn play to directly reference another Ayckbourn play ( Relatively Speaking) within the story.
The play was filmed by the French director Alain Resnais, as Aimer, boire et chanter (2014).
Life of Riley is a 2014 French comedy-drama film directed by Alain Resnais in his final feature film before his death. Adapted from the play Life of Riley by Alan Ayckbourn, the film had its premiere in the competition section of the 64th Berlin International Film Festival, just three weeks before Resnais died, where it won the Alfred Bauer Prize.
Usage examples of "life of riley".
Whereas he'd never discovered anything, yet lived the life of Riley, doing marvelous work for the Foundation, guiding international funds to aid the sick and suffering in backward nations.