How could a rogue planet harbor life?

Could a rogue planet's moons harbor life?

If the proper chemical bath on this moon emanates from hydrothermal springs at the bottom of an ocean, it could potentially harbor creatures such as those found around such sources on earth.

Here's a quote from an article on the subject in NASA Science News:

Instead of photosynthesis, Vent ecosystems get their energy from chemicals in a process called "chemosynthesis". Both methods involve an energy source, carbon dioxide, and water to produce sugar. Photosynthesis gives off oxygen gas as a by-product, while chemosynthesis creates sulfur ... Because they offer an alternative way for life to meet basic energy needs, these vent ecosystems have piqued the interest of astrobiologists - scientists who study the plausibility of life start elsewhere in the universe.

The level of tidal warming required for volcanic activity at this level is seen in our solar system on Io, Jupiter's inner moon. In IO's case, it would not stay eccentric enough in orbit for those forces to act on it that way if the other major moons of Jupiter did not prevent its orbit from circulating. So for such a model there would have to be several moons around this rogue planet that orbit in a certain way.

There may also be conditions under which rogue planets can support life without moons, as explored in the article The Steppenwolf: A Proposal for a Habitable Planet in Interstellar Space:

We find that a rogue planet of Earth-like composition and age could sustain a subglacial liquid ocean if it were about 3.5 times as massive as Earth, which is about 8 km of ice. Suppression of the melting point by impurities, a layer of frozen gas, or a larger amount of water could significantly reduce the planetary mass required to maintain a liquid ocean.