How to find the local port a rails instance is running on?

Question

So I would like my Rails app instances to register themselves on a \"I\'m up\" kind of thing I\'m playing with, and I\'d like it to be able to mention what local port it\'s

Answer 1

Building on the other answers (which saved my bacon!), I expanded this to give sane fallbacks:

In development:

port = Rails::Server::Options.new.parse!(ARGV)[:Port] || 3000 rescue 3000

In all other env's:

port = Rails::Server::Options.new.parse!(ARGV)[:Port] || 80 rescue 80

The rescue 80 covers you if you're running rails console. Otherwise, it raises NameError: uninitialized constant Rails::Server. (Maybe also early in initializers? I forget...)

The || 80 covers you if no -p option is given to server. Otherwise you get nil.