Define host so absolute urls work in development and test

[jonathanhefner]

This is definitely a source of confusion. The information out there is very mixed, so I did some testing to verify…

@ansonhoyt

Perhaps a single base config. Say config.routes.default_url_options that all others extend

This currently (at least in master branch) exists as Rails.application.default_url_options (which is actually an alias for Rails.application.routes.default_url_options).

@ansonhoyt

Perhaps no config for development and test. Just assume localhost:3000 . Detect how the server was started rails server -p 1234 or rails server --binding 0.0.0.0 so it “just works”.

This currently works already in regular controllers / views, except the information is taken from the request rather than from how the server was launched. Unfortunately, that means it does not work in Action Mailer views, since there is no request as such. I agree it would be nice to have though!

@Betsy_Haibel

I worry that #2 might provide a false sense of security and just push the config sadness to “emergency live production debugging.”

This is a good point. I think we could add a config option similar to config.require_master_key but for default_url_options[:host]. That would also be more reliable than hoping the user bumps into a “Missing host” error on their own in development.