Add -p and --port flag

[topfunky]

It would be useful if puma supported the -p and --port flags like the rackup command so it can be run on any port.

[mrrooijen]

+1: That would make it usable on Heroku as well since you have to bind to a port on their Cedar stack. They do not support UNIX/TCP sockets as far as I know. Also, Bamboo used HTTP 1.0, but the new Cedar stack uses HTTP 1.1.

Just not sure whether Puma was meant to run under using Rubinius rather than Ruby 1.9.x because of the GIL. Heroku only allows for Ruby 1.9.2 at this time. But, if it still offers a performance (concurrency) improvement even under Ruby 1.9.2 that would be nice.

Still, I would imagine this would be great to run under RBX with the GIL removed. Would love to try that on a VPS/EC2, and hope Heroku will support RBX at some point.

[mrrooijen]

Actually if you run it through the Rails executable you can assign a port with -p. But, I'm not sure whether you're able to set any Puma-specific options along with it.

rails server puma -p 5000

But if you wanted to increase the amount of threads it's allowed to spawn, not sure if you can. The -t option isn't available because this is actually the rails cli, not the puma cli.

Though, in any case I guess it might be better to be able to bind to a port directly from Puma itself.