Dan Peterson is the new Rails sysadmin, fixes Trac

Our trusty Rails server Wrath was generating cruft and crust faster than you could say we-have-no-sysadmin, so at RubyConf we decided to remedy the situation and ask for help. Dan Peterson stepped up to the plate and is now officially the new Rails systems administrator. Welcome on board, mate!

And wasting little time, he has already cleaned a few rough corners for performance and, more importantly, upgraded and fixed Trac — the software that runs dev.rubyonrails.com. So no more timeouts, better performance, more features.

Better findings with named placeholders

Robby on Rails has a great introduction to named placeholders in Rails. Making ActiveRecord::Base.find more readable and secure at the same time, what’s not to like? Please Robby, or someone else, turn a succinct version of this argument into a documentation patch.

Introducing SwitchTower: Distributed deployment for Rails

SwitchTower is a utility for executing commands in parallel on multiple machines. It lets you (among many other things) deploy distributed applications with a single command.

When your application is young you may be deploying it to a single machine, which runs the web server, app server, and database all together. In this situation, deploying manually is not unbearably painful. But as your application grows you may find yourself needing to deploy your application to two web servers, four app servers, and two database servers, atomically. This is where SwitchTower steps in as a pain-killer.

Getting Started

Suppose you have an existing Rails application that you want to deploy to a cluster of machines. SwitchTower attempts to make the entire process as painless as possible:

  • Install SwitchTower. This is as simple as gem install switchtower.
  • Decorate your application with the necessary SwitchTower files. Just do switchtower --apply-to /path/to/your/app.
  • Tell SwitchTower where your application code sits and what machines it should deploy to. Just edit config/deploy.rb and fill in the blanks.
  • Set up your machines so they are ready to receive your application. It’s as easy as rake remote_exec ACTION=setup.
  • Lastly, deploy your application! Just type rake deploy and let the good times roll.

Other Capabilities

In addition to simply moving your application to the various boxes, SwitchTower attempts to make the task of maintaining your deployment simpler. Suppose something goes wrong while checking out your code—SwitchTower will detect that and roll back the change, on all deployed machines. This means it is much harder to wind up with your application out of sync on the various boxes.

Other things SwitchTower can do, out of the box:

  • Database migrations on your production database
  • Enable/disable the web interface (only works with Apache currently)
  • Restart your application on the application servers

SwitchTower also makes it very simple to override and extend the standard tasks, and to write your own. The tasks use a simple language similar to Rake that allows you to automate many different tasks.

More Information

Want to know more about SwitchTower? There’s an entire user manual full of useful tidbits at http://manuals.rubyonrails.com/read/book/17.

Rails 1.0: The Release Candidate (2)

The release of 1.0 is near upon us! It has been a long time in the making, involved a heroic final sprint at RubyConf by the core team, and is a testament to how it’s all been coming together over the last months. Almost three hundred bug fixes, enhancements, and new features have been introduced since 0.13.1 saw the light of day three months ago. That’s on average three per day. So it’s not been a while because of slacking off.

But with all these changes, we want to allow for an extended release-candidate phase before we declare 1.0 a reality. So from today you can get the 1.0 RC 2, which is packaged as version 0.14.1 in the gems.

Over the next two weeks or so, we’re very interested in hearing about bugs and we’ll likely push out a few more release candidates as more and more fixes go in. That said, we can’t fix it all and we surely can’t process all the pending feature enhancements for 1.0. So don’t expect to see an empty Pending Patches or Faults lists. Our main objective is to stamp out the “heinous” bugs: those that significantly affect the many or those that dangerously affect the few.

(The main gem server is pretty over-worked, you may want to do gem install rails --source http://gems.rubyonrails.org --include-dependencies to offload it a bit)