default config should include passenger_root and passenger_ruby

[deric]

The package should work out of box, so the variables should be defined according to versions ruby and passenger on which was package built.

[elmatou]

These are included in conf.d/passenger.conf

But packaging means portability, that is why passenger_root should be set to a vendored or packaged version of passenger with a predictible path or with passenger-config --root in the postinst script but this will break RVM compatibility.

passenger_ruby is a bit more tricky to set, depending of the version of ruby you use (source, debian package or RVM) the path to the interpreter can change, even between different webapp (passenger 4.0 allow to use several ruby version with RVM)

I think we can trigger passenger-config --ruby-command in the postinst script.