Setting up Rails applications with cPanel

Having worked only with Apache/FCGI deployment of Rails during my day job (which in itself is a whole different bucket of pain), setting it up with cPanel looked like it should have been a breeze. Unfortunately there was a few catches which caused me no end of pain. I’ve got the excellent book, Deploying Rails Applications, but its information on shared hosting was rather skimpy, and did not seem to be directed towards hosts with cPanel installed. (I’d still recommend this book as a must for any serious Rails developers. It is incredibly useful.)

So here, documented, is the whole process in cPanel (although it will require ssh access to the server). I did find a good reference, but it didn’t address a specific problem I was having. (More on that later…)

Setting up the Rails application

From the Ruby on Rails menu option, generate a new application. cPanel will automatically generate a location for the application at ~/public_html/appname. Unfortunately, using this location makes the whole application’s code available to the public, so a better idea is to deploy to a subdirectory off your home directory, e.g. ~/rails_apps/appname. This can just be changed manually in the textbox. Select ‘Load on boot’ and production mode and hit create.

What you get

This will generate a rails application skeleton in ~/rails_apps/appname, as well as setting up the necessary values in ~/.cpanel/ruby-on-rails.db. In spite of its name, this is actually a YAML file which stores the deployment information for the app.

It should look something like this:

# ~/.cpanel/ruby-on-rails.db
---
-
  env: production
  loadonboot: 1
  name: appname
  path: /rails_apps/appname
  port: 12040

Pretty self-explanatory, really. Each of the entries lines up with particular values in cPanel, with the port automatically assigned during the creation process.

As far as the application itself, I’ll echo the suggestion in the wiki article mentioned above and suggest that you delete the skeleton application (leaving the directory only) and deploy your application either using Capistrano or a subversion checkout (e.g., from ~/rails_apps/appname:

svn co http://svn.yoursite.com/svn/trunk .

I use Unfuddle for my subversion hosting, since I can have free private repos; the other popular option for Rails is GitHub. If you’re up to the challenge, you can always set up your own subversion repository on your site (as per the example).

Creating the redirect

The aforementioned wiki article suggested not using the redirect option in cPanel; I didn’t have a problem with it, however. Create a redirect for the directory in which the rails application resides from the URL. I’ll assume it’s a stand-alone app (no other rails apps on the server), so it should redirect to the root of yoursite.com (or more correctly, a request to yoursite.com will redirect to this rails application running on this port).

The redirect in cPanel will create a redirect along the lines of:

APPNAME	REWRITE URL	ACTIONS
appname	http://yoursite.com/ → http://yoursite.com:12040/	[SAVE] [DELETE]

What you get

Similar to the application creation, this generates/populates the file ~/.cpanel/ruby-on-rails-rewrites.db, which looks something like this:

# ~/.cpanel/ruby-on-rails-rewrites.db
---
-
  appname: rails_app
  domain: yoursite.com
  port: 12040
  rewritebasepath: /home/username/public_html
  url: ''

where username is replaced with your username.

Here is where I ran into problems. The ruby-on-rails-rewrites.db file is not the only location this writes to; however, it is the only one which is deleted if you delete the rewrite in cPanel. In creating the rewrite, cPanel also writes to ~/public_html/.htaccess, a point which eluded me for several days. (No matter what I did, it was always trying to redirect to a path/application which no longer existed…) The following lines will be added to .htaccess:

RewriteCond %{HTTP_HOST} ^yoursite.com$ [OR]
RewriteCond %{HTTP_HOST} ^www.yoursite.com$
RewriteRule ^(.*)$ "http\:\/\/127\.0\.0\.1\:12040%{REQUEST_URI}" [P,QSA,L]

These lines must be deleted if you wish to remove the redirect entirely (e.g. you have moved the application, written a new application to be the default, changed ports, or you simply fucked up and want to start over.)

And that’s it. Almost.

Mongrel

Although there is a start application option in cPanel, I was finding this unresponsive at times, so I simply started mongrel manually. This is simply:

mongrel_rails start -e production -d -p 12040 -P log/mongrel.pid

Now, that’s all. I don’t know if anyone else has/had the same problem I did. If so, I hope this helped.

~ by MattR on December 18, 2008.