Error when running rails as root

My rails application is working well under my user:

$ rails server
=> Booting WEBrick
=> Rails 3.0.5 application starting in development on htttp://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
[2011-03-30 01:56:29] INFO  WEBrick 1.3.1
[2011-03-30 01:56:29] INFO  ruby 1.9.2 (2011-02-18) [x86_64-darwin10.7.0]
[2011-03-30 01:56:29] INFO  WEBrick::HTTPServer开发者_如何学JAVA#start: pid=3899 port=3000

But I need to run it under port 80, so running it as sudo gives me this:

$ sudo rails server -p 80
/Users/jamez/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems.rb:900:in `report_activate_error': Could not find RubyGem rails (>= 0) (Gem::LoadError)
    from /Users/jamez/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems.rb:248:in `activate'
    from /Users/jamez/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems.rb:1276:in `gem'
    from /Users/jamez/.rvm/gems/ruby-1.9.2-p180/bin/rails:18:in `<main>'

More info:

$ ruby -v
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-darwin10.7.0]

$ sudo ruby -v
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-darwin10.7.0]

$ rails -v
Rails 3.0.5

$ sudo rails -v
/Users/jamez/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems.rb:900:in `report_activate_error': Could not find RubyGem rails (>= 0) (Gem::LoadError)
    from /Users/jamez/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems.rb:248:in `activate'
    from /Users/jamez/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/site_ruby/1.9.1/rubygems.rb:1276:in `gem'
    from /Users/jamez/.rvm/gems/ruby-1.9.2-p180/bin/rails:18:in `<main>'

$ gem list --local rails

*** LOCAL GEMS ***

rails (3.0.5)

$ sudo gem list --local rails

*** LOCAL GEMS ***

rails (3.0.5)

$ gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 1.6.2
  - RUBY VERSION: 1.9.2 (2011-02-18 patchlevel 180) [x86_64-darwin10.7.0]
  - INSTALLATION DIRECTORY: /Users/jamez/.rvm/gems/ruby-1.9.2-p180
  - RUBY EXECUTABLE: /Users/jamez/.rvm/rubies/ruby-1.9.2-p180/bin/ruby
  - EXECUTABLE DIRECTORY: /Users/jamez/.rvm/gems/ruby-1.9.2-p180/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-darwin-10
  - GEM PATHS:
     - /Users/jamez/.rvm/gems/ruby-1.9.2-p180
     - /Users/jamez/.rvm/gems/ruby-1.9.2-p180@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

$ sudo gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 1.6.2
  - RUBY VERSION: 1.9.2 (2011-02-18 patchlevel 180) [x86_64-darwin10.7.0]
  - INSTALLATION DIRECTORY: /Users/jamez/.rvm/gems/ruby-1.9.2-p180
  - RUBY EXECUTABLE: /Users/jamez/.rvm/rubies/ruby-1.9.2-p180/bin/ruby
  - EXECUTABLE DIRECTORY: /Users/jamez/.rvm/gems/ruby-1.9.2-p180/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-darwin-10
  - GEM PATHS:
     - /Users/jamez/.rvm/gems/ruby-1.9.2-p180
     - /Users/jamez/.rvm/gems/ruby-1.9.2-p180@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

Any idea of what's going on? How can I make it work with and without sudo?

RVM is preventing sudo from seeing the Rails binary.

To get around this, use rvmsudo:

> rails -v
Rails 2.3.11

> sudo rails -v
/Users/dan/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/site_ruby/1.8/rubygems.rb:779:in `report_activate_error': Could not find RubyGem rails (>= 0) (Gem::LoadError)
        from /Users/dan/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/site_ruby/1.8/rubygems.rb:214:in `activate'
        from /Users/dan/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/site_ruby/1.8/rubygems.rb:1082:in `gem'
        from /Users/dan/.rvm/gems/ree-1.8.7-2010.02@crm/bin/rails:18

> rvmsudo rails -v
Rails 2.3.11

You are using Rails 3, which uses Bundler, which installs gems on a per-user basis, so before you can run the app as a given user, you must first run bundle install while logged in as that user. I think that will make it work for you.

By the way, I assume you know that running anything as root is risky. You probably want to configure Apache and Passenger (or something like that) to serve up your Rails application over port 80.