WebFaction Rails Stack

The accompanying shell script will automatically build and configure your own private Ruby on Rails stack. It was written with WebFaction users in mind, but is more or less generic aside from a few minor details. Essentially, the directories $HOME/logs/user and $HOME/webapps/$APP_NAME must exist before running the script.

There are now two stack scripts, the classic one, webfaction.sh, and a new one, webfaction-alt.sh. The classic one is a monit/nginx/ruby 1.8.7 MRI/thin stack and the new one is an nginx/ruby enterprise edition 1.8.6/passenger stack. The classic script includes passenger and the passenger nginx module in case you want to give it a whirl. Now that passenger works with nginx, it has become the clear choice. It is certainly simpler. However, although the new stack uses less physical memory, the rss is often higher. This is because of multiple counting. Depending on how WebFaction meters memory usage, this could be a practical downside.

To compare your total rss vs your total private dirty rss (physical memory usage) run these commands:

ps -u $USER -o rss | grep -v peruser | awk '{sum+=$1} END {printf("\n%.0fMB total RSS\n", sum/1024)}'
(ps -u $USER -o pid | awk '{ print "grep Private_Dirty /proc/"$1"/smaps" }' | sh | awk '{ sum += $2 } END { printf("%.0fMB total Private Dirty RSS\n\n", sum/1024) }') 2>/dev/null

You will see that your actual physical memory usage is much smaller than what rss reports.

Classic Script

What's Provided

• Ruby 1.8.7 (latest from the 1.8.7 subversion branch)
• Latest RubyGems
• Gems: rails, thin, capistrano, termios, god, sqlite3-ruby, mysql, typo, and passenger
• Git 1.6.2.4
• nginx 0.6.36 (with nginx-upstream-fair module for fair load balancing and passenger module)
• Monit 5.0
• Startup scripts and working default configuration files for monit and nginx

Before Running the Script

1. Create a rails app from the WebFaction control panel. Leave the autostart box unchecked.
2. Create an app of type "custom application (listing on port)" from the WebFaction control panel. Name it monit.
3. Assign values to the four variables at the beginning of the script: PREFIX, APP_NAME, APP_PORT, and MONIT_PORT.
   • PREFIX is the installation path prefix. It is the location of your "private application environment". It should be somewhere in your home directory. It has a default value of $HOME/apps. You could make it $HOME, but the home directory contains things that are better off separate. With a compartmentalized PREFIX like $HOME/apps, if you aren't happy with your setup, you could simply kill the monit, nginx, and thin processes, execute rm -rf $HOME/apps and start over fresh.
   • APP_NAME is the name of the app created in step one. The path $HOME/webapps/$APP_NAME should exist and contain at least a skeleton app. The default value for APP_NAME is blog.
   • APP_PORT is the port WebFaction assigned to the app created in step one. The default value is 4000.
   • MONIT_PORT is the port WebFaction assigned to the app created in step two. The default value is 4002.

After Running the Script

If no unforeseen errors occurred, your rails app will be up and running in production mode. Of course, $HOME/webapps/$APP_NAME must contain a valid app for this to be true, even if it's just a skeleton. The working default configuration sets up two thin instances listening on unix sockets (mongrel does not have this capability) with nginx as the fair load balancing reverse proxy. Monit watches nginx and the thin servers. A crontab entry ensures that your setup springs back to life when the server has to reboot. There are a couple of optional things you should do:

1. Inspect the nginx and monit conf files to learn how they work. Modify them as you like.
2. Generate ssl certificates and create an nginx https vhost following my example file if you have a dedicated IP address for https traffic.

New Script

What's Provided

• Ruby Enterprise Edition 1.8.6 - 20090201
• Latest RubyGems
• Gems: rack, rails, mysql, sqlite3-ruby, passenger, thin, capistrano, termios
• Git 1.6.2.4
• nginx 0.6.36 (with nginx-upstream-fair module for fair load balancing and passenger module)
• Startup scripts and working default configuration files for nginx

Before Running the Script

Follow Steps 1 and 3 for the classic script, and ignore monit related information in Step 3.

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