Solution found!
This appears to be a bug specific to Mongrel + Rails 2.3.8, the webserver used by Rails+cPanel. This is why it only shows up when you run the app from cPanel, but not when serving it locally via script/server.
For more details, see: https://rails.lighthouseapp.com/projects/8994/tickets/4690-mongrel-doesnt-work-with-rails-238
The eventual workaround found is to put the following file in the /config/initializers directory of each new Rails 2.3.8 app:
https://gist.github.com/471663
Once I add this initializer, my Rails app functions as expected.
Original question:
I've gone through the very helpful tutorial at railsforzombies.org and am now ready to get a test RoR install going. My site is on a shared host, using cPanel. I've created the test application using cPanel, and it's set up at ~/rails_apps/blog. I created a rewrite that redirects mydomain.com/testblog/ to mydomain.com:12002, which is the port that cPanel has my RoR app running on. I also started the application via cPanel, in development mode.
If I go to mydomain.com/testblog/, I see the helpful page that lets me know that my RoR app has been created and is functioning. Great, right? Well, not so fast.
I'm following along with the Getting Started guide at guides.rubyonrails.org/v2.3.8/getting_started.html, and I get to step 4. I've run script/generate controller home index and edited the resulting view at app/views/home/index.html.erb. It's just a simple
<h1>Hello rails!</h1>
However, when I go to mydomain.com/testblog/home/index (with or without the trailing '/'), I get a blank page in my browser, nothing at all (View Source shows nothing).
To make sure that I'm not going crazy, I put a text file in my rails app's /public directory, and when I go to mydomain.com/testblog/test.txt, it gets served properly. So I know that the Apache rewrite from cPanel is working properly.
Any ideas? I figure I'm overlooking something that's obvious, but I'm drawing a blank for now.
For reference, I'm running on cPanel 11, Ruby 1.8.7 and Rails 2.3.8. I would love to be running Rails 3.0, but the shared host says it's a no-go for now.
edited to add:
Generating the home controller and index action above added the following lines to my routes.rb file (I've checked, they're there):
map.connect ':controller/:action/:id'
map.connect ':controller/:action/:id.:format'
so mydomain.com/testblog/home/index should map to app/views/home/index.html.erb.
Edited again with more investigation details:
I found something that may shed some light on this. If I stop the rails app in cPanel, then log in via PuTTY and start the dev server with script/server and execute
curl http://0.0.0.0:3000/home/index
the dev server does respond with
<h1>Hello Rails!</h1>
from app/views/home/index.html.erb. So it's working there. It's when I start the Rails app in cPanel (which tells me its running on port 12002) that I get an empty response from mydomain.com/testblog/home/index. I also get an empty response from
curl http://0.0.0.0:12002
if I run it via SSH on the server. So it looks like something screwy with cPanel, not with Rails.
Did you make sure and delete your index.html file in the app/public directory of your app?
Also, after generating the home controller, did you setup your routes.rb to recognize the new controller and action?