Sinatra Howto

[budding_mechanic]

I figured out how to run the Sinatra ruby gem on Bluehost. Although I'm using Rails, I've documented this for anyone else.

ASSumptions:

* You have your own [sub]domain and know how to point it from the
public_html directory to another directory in your account.

* You have ssh access.

* No Ruby or Gem environment variables are set. If you've setup
GEM_HOME elsewhere, that's fine, just adjust paths accordingly.

1. Install the Sinatra ruby gem

$ gem install sinatra
WARNING:  Installing to ~/.gem since /usr/lib/ruby/gems/1.8 and
	  /usr/bin aren't both writable.
WARNING:  You don't have /home/XXXXXXX/.gem/ruby/1.8/bin in your PATH,
	  gem executables will not run.
Successfully installed rack-0.9.1
Successfully installed sinatra-0.9.1.1
2 gems installed
Installing ri documentation for rack-0.9.1...
Installing ri documentation for sinatra-0.9.1.1...
Installing RDoc documentation for rack-0.9.1...
Installing RDoc documentation for sinatra-0.9.1.1...

2. Verify installation

$ irb
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'sinatra'
=> true
irb(main):003:0> Gem.path
=> ["/home/XXXXXXXX/.gem/ruby/1.8", "/usr/lib/ruby/gems/1.8"]

Make note of the Gem.path array that lists your local gem directory. Eg.

/home/XXXXXXXX/.gem/ruby/1.8

3. Create Sinatra directory

You probably don't want to put your Sinatra directory in ~/public_html...

Bluehost seems to put Rails apps in ~/etc/rails_apps.

So let's use ~/etc/sinatra/myapp.

$ cd ~/etc
$ mkdir -p sinatra/myapp

4. Setup .htaccess

Paste this file into: ~/etc/sinatra/myapp/.htaccess

Set permissions:

chmod 644 ~/etc/sinatra/myapp/.htaccess

# General Apache options
AddHandler fcgid-script .fcgi
AddHandler cgi-script .cgi
#Options +FollowSymLinks +ExecCGI

# If you don't want Rails to look in certain directories,
# use the following rewrite rules so that Apache won't rewrite certain requests
# 
# Example:
#   RewriteCond %{REQUEST_URI} ^/notrails.*
#   RewriteRule .* - [L]

# Redirect all requests not available on the filesystem to Rails
# By default the cgi dispatcher is used which is very slow
# 
# For better performance replace the dispatcher with the fastcgi one
#
# Example:
#   RewriteRule ^(.*)$ dispatch.fcgi [QSA,L]
RewriteEngine On

# If your Rails application is accessed via an Alias directive,
# then you MUST also set the RewriteBase in this htaccess file.
#
# Example:
#   Alias /myrailsapp /path/to/myrailsapp/public
#   RewriteBase /myrailsapp

RewriteBase /
RewriteRule ^$ index.html [QSA]
RewriteRule ^([^.]+)$ $1.html [QSA]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ dispatch.fcgi [QSA,L]

# In case Rails experiences terminal errors
# Instead of displaying this message you can supply a file here which will be rendered instead
# 
# Example:
#   ErrorDocument 500 /500.html

ErrorDocument 500 "<h2>Application error</h2>Rails application failed to start properly"

Ref:

http://helpdesk.bluehost.com/index.p...article/000493

5. Setup dispatch.fcgi

This file is the bread and butter that starts your Sinatra app.

Paste this file into: ~/etc/sinatra/myapp/dispatch.fcgi

Set permissions:

chmod 755 ~/etc/sinatra/myapp/dispatch.fcgi

Edit the path to your gem dir as recorded in step #2.

#!/usr/bin/ruby
#
# Sample dispatch.fcgi to make Sinatra work on Bluehost
#
# http://www.sinatrarb.com/
#

require 'rubygems'

# *** CONFIGURE HERE ***
# Because the fcgi environment is sterile make sure to prepend
# local gem dir to front of gem path.  Find gem dir with:
#   $ ruby -e 'require "rubygems"; p Gem.path.shift'
Gem.path.unshift("/home/XXXXXXX/.gem/ruby/1.8")

# sinatra should load now
require 'sinatra'
 
module Rack
  class Request
    def path_info
      @env["REDIRECT_URL"].to_s
    end
    def path_info=(s)
      @env["REDIRECT_URL"] = s.to_s
    end
  end
end

# Define your Sinatra application here
class MyApp < Sinatra::Application
  get '/hi' do
    "Hello World!"
  end
end

builder = Rack::Builder.new do
  use Rack::ShowStatus
  use Rack::ShowExceptions

  map '/' do
    run MyApp.new
  end
end

Rack::Handler::FastCGI.run(builder)

6. Testing

Now you need to make the Sinatra directory live.

Symlink your domain to the Sinatra directory.

$ cd ~/public_html
$ ln -s ~/etc/sinatra/myapp mydomain

http://www.mydomain.com/hi (returns "hello world")

http://www.mydomain.com (returns Sinatra error message as no route exists)

Notes:

There might be a better way to do this last step; I've only linked a subdomain, never a top level domain.

Sinatra does have a directory layout that is similar to Rails, but I've ignored that for simplicity.

There's lots more info about Sinatra and Rack.

http://www.sinatrarb.com/
http://rack.rubyforge.org/

Don't use cPanel to setup Sinatra; use command line.

Good luck.

Keywords: sinatra rack ruby rails dispatch.fcgi

[Sonja]

I don't understand the line:

ln -s ~/etc/sinatra/myapp mydomain

What info do I write instead of mydomain? Let's assume I want the action to happen in an add-on domain such as "public_html/foo".

Sonja

[AbeEstrada]

I get this error

user@domain.com [~/public_html]# gem install sinatra
Successfully installed sinatra-0.9.4
1 gem installed
Installing ri documentation for sinatra-0.9.4...
Installing RDoc documentation for sinatra-0.9.4...

user@domain.com [~/public_html]# gem install rack
Successfully installed rack-1.0.1
1 gem installed
Installing ri documentation for rack-1.0.1...
Installing RDoc documentation for rack-1.0.1...

user@domain.com [~/public_html]# irb
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'sinatra'
LoadError: no such file to load -- sinatra
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
	from (irb):2

[roso]

I get this error

user@domain.com [~/public_html]# gem install sinatra
Successfully installed sinatra-0.9.4
1 gem installed
Installing ri documentation for sinatra-0.9.4...
Installing RDoc documentation for sinatra-0.9.4...

user@domain.com [~/public_html]# gem install rack
Successfully installed rack-1.0.1
1 gem installed
Installing ri documentation for rack-1.0.1...
Installing RDoc documentation for rack-1.0.1...

user@domain.com [~/public_html]# irb
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'sinatra'
LoadError: no such file to load -- sinatra
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
	from (irb):2

Um, what does that mean? Anybody else try the tutorial?

[JadedEvan]

I get this error

user@domain.com [~/public_html]# gem install sinatra
Successfully installed sinatra-0.9.4
1 gem installed
Installing ri documentation for sinatra-0.9.4...
Installing RDoc documentation for sinatra-0.9.4...

user@domain.com [~/public_html]# gem install rack
Successfully installed rack-1.0.1
1 gem installed
Installing ri documentation for rack-1.0.1...
Installing RDoc documentation for rack-1.0.1...

user@domain.com [~/public_html]# irb
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'sinatra'
LoadError: no such file to load -- sinatra
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
	from (irb):2

Judging by the error output from irb, it looks like you are running the system irb which is probably requiring the system gems, not the local gems in your user directory ( ~/.gem/). Have you modified your ~/.bash_profile or ~/.bashrc to accept a local gem path ?