These options are now defaulted to 127.0.0.1 for security and paranoid reasons.
To rackup
here: https://github.com/rack/rack/blob/28b014484a8ac0bbb388e7eaeeef159598ec64fc/lib/rack/server.rb#L187
To padrino s
here https://github.com/padrino/padrino-framework/blob/5fe35ccbd2ffbf78d78233e9a47759eff1c6cc92/padrino-core/lib/padrino-core/cli/base.rb#L16
Considering your desire to host development mode app on local Ethernet, you have a dedicated server and you should have no problem setting up something like Passenger to host your app.
BTW, version 1.5.2
of rack
still hosts the config.ru
on 0.0.0.0
, if you are locked on this version you can use rackup
to host your development app for local network.