Creating a Rails Development Environment on Mac OS X

I’ve been writing Ruby on Rails apps for several years now, and both at my day job, and my contract work, I’ve been utilizing a modified version of the Locomotive Project from Ryan Raaum. I rebranded it as “MiCodaLoco” for our use, and modified it to be a little more modular for it’s startup environment, moving the MacPorts distribution it used to a central folder and out of the “bundles” it used for each Ruby and RubyGems environments.

It worked out quite nicely for several years. But it was a complete pain to rebuild ruby and rails versions, because I never took the extra steps to automate the bundle building process. I always had grand plans to create a “debug” button as well to launch mongrel (or thin, about the only change I’ve made in the last year has been to start thin instead of mongrel for one of our apps that ran into a problem with Rails 2.3.8 and/or Rack changes and cookies and mongrel) in debugging mode for ruby-debug.

I had poked my way around the Objective-C app, and I understood where to make modifications I needed, but I didn’t really understand how the app was put together (and parts of it were pre-Interface Builder and had code created interface that I still don’t totally grok, even after a week long iPhone training that had enough Obj-C in it to make me dangerous).

Best-laid plans being what they are, I never did update it, and it was time to move on. With a Rails 3 and possibly a Ruby 1.9 update in the next six months to year for all these apps – I wanted to spend more time on that than learning Cocoa. So I needed something new.

Enter Homebrew, RVM, and Passenger standalone.

Homebrew

So, I’ve been a Fink, then DarwinPorts MacPorts user forever, and would recommend it to anyone to get open source packages (like wget, or wireshark) that don’t come already with OS X. But sometimes suggesting it to your colleagues just to install something to facilitate something else doesn’t always go over well.

Enter Homebrew. Because Homebrew uses a lot of of what’s already there in OS X instead of installing it’s own versions, it’s faster to get the packages you need (with the risk that something is broken with an OS update, but I haven’t seen something like that in a while with 10.5/10.6 on Intel). And in our case, we only need the mysql client libraries for the mysql gem, and the imagemagick libraries for the rmagick. And wget. Because everyone needs wget.

It’s easy to get started, just follow the instructions (The system admin in me recommends you look at the executed ruby script first – but I know you won’t).

Oh, you need Xcode. You do have Xcode installed right? Even the designers need it for the iPhone emulator. Trust me.

In our case we needed to

brew install mysql
  • which installs mysql server, but we use MAMP for that, so it’s just for the libraries (in theory, you probably can just link the mysql gem against the MAMP libraries if you use MAMP. But I don’t want some MAMP upgrade where I put it in a different path wreak havoc on that). We also needed to

    brew install imagemagick

. And if you are testing your caching code and use memcache,

brew install memcached

You might need something else installed, but we haven’t as of yet.

RVM

RVM is everything I ever wanted doing multiple Locomotive/MiCodaLoco bundles to be, and then some, with the added bonus that somebody else does it.

RVM lets you run multiple rubies and multiple gemsets per ruby installation, making it really convenient to not only switch between them for testing and dev purposes, but also just to have an effective development environment.

RVM’s documentation is very comprehensive, though it can be a little tricky to get started. Here’s what we needed (after installing RVM):

rvm install ree                           # I use ruby enterprise edition - version 1.8.7 on our, ree is a shortcut string for this version - see "rvm strings" for morervm gemset create busterleague # creates a gemset for a person project of minervm --default ree@busterleague  # sets my default ruby to ree and the default gemset to busterleaguervm use ree@busterleague        # sets up the session to use ree and the busterleague gemsetgem install rails --version=2.3.10  # still at rails 2gem install passenger               # passenger v3gem install ...                           # rest of gems

As a convenience – because you like will end up shifting between rubies – or at least gemsets – create some bash aliases to make that easier (Locomotive/MiCodaLoco had a “open terminal” command for each project that automatically put one into the right bundle environment and the working directory for the project, these aliases replace that as well).

Here’s mine for my work, contract, and personal projects (I put my working directories in a “dev” subdirectory to my home directory)

alias rubydevprompt='PS1="rubydev:W ($(~/.rvm/bin/rvm-prompt i v g))$ "'alias smallwonder='rubydevprompt && rvm use ree@trixietracker && cd ~/dev/tt/smallwonder'alias darmok='rubydevprompt && rvm use ree@extension_production && cd ~/dev/extension/darmok'alias dega='rubydevprompt && rvm use ree@extension_production&& cd ~/dev/extension/dega'alias busterleague='rubydevprompt && rvm use ree@busterleague && cd ~/dev/personal/dmbdraft'

I can then switch between them at ease, add more to do things like start passenger (more on that below), or to use development gemsets, like rails 3 (and even add git commands to make sure I’m in the right branch (ala rails 3)

rvm-prompt has a nice documentation page

Passenger

Finally, I use Passenger in standalone mode running on an arbitrary port to deliver the dev versions of our apps (actually I use passenger everywhere, currently running under Apache, it’s made my system admin life much easier than other rails environments).  After installing passenger, just run the “passenger start” command, and it will self-install and configure a version of nginx that it uses to do this.

As a convenience, I’ve created a ruby script that starts passenger with a set of default parameters – which can be overridden by a yaml configuration file – or from the command line. I called this “script/devserver” to distinguish it from the rails webrick “script/server” command.

You can see a version of that devserver script at github

What I probably need to do is go back and have a debugging option that would start webrick, mongrel, or thin in order to use it with ruby-debug (since Passenger 3 isn’t really setup to support ruby-debug)

[Update] You probably want this link to the devserver scripthere’s why.

Heading into Rails TOOOOOO-TOOOOOO-TOOOOOO!

When I played little league baseball we had announcers for the game, one of which was some nice old guy in a ramshackle shelter behind home plate that was the “booth” – and every time there’d be two outs, two strikes and two balls – he’d croon “TOOOOO-TOOOOO-TOOOO”. Which of course, has little to do with this post other than version numbers.

Rails 2.2 was just released – so of course, I’m taking the most critical application we have (well, maybe the second critical, and that’s really only because other apps depend on it, it’s not critical in terms of features) – and upgrading it first, because, well, that’s how system administrators roll.

The release notes are great. Seriously. Really great. So great I shouldn’t even be writing this post. Which I am anyway – because here are some of the highlights of what I had to change to make my app work.

NoMethodError for Association Methods

Getting exceptions when you go to Rails 2.2.2 that don’t say anything more than NoMethodError when you know good and damn well the method that it’s saying no method on exists? Yeah, me too. And I bet it’s a method in an associated model. And if it is, you probably should be ashamed of yourself.

Rails 2.2 now enforces privacy on private methods called through associations. So in my case, I had two issues, 1) I was calling “update” on an associated model in some code I blindly copied and pasted a long time ago, and 2) I have a few of my own SQL queries that I’m not entirely sure how to do using Rails associations and named scopes, and I was cheating by calling self.connection.sanitize_limit to take advantage of Rails’ own function for cleaning up provided “LIMIT” params. And sanitize_limit, like the instance method update is private.

Update Rails Footnotes

If you use Rails footnotes in development mode – you’ll want to update for this change for Rails 2.2 compatibility.

Aside… Piston 1.9.5

A great way to stay current with Rails plugins is to use Piston – which has a new 1.9.5 release. You can build your own.

“quoted_table_name” and Has Many Polymorphs

If you start getting some error about undefined method quoted_table_name’` and you use has_many_polymorphs – you’ll want this change.

I don’t use the plugin, I use the gem. So I built my own has_many_polymorphs 2.12.1 gem – by doing: ` gem install echoe git clone git://github.com/fauna/has_many_polymorphs.git cd has_many_polymorphs `

edit CHANGELOG with a “v2.12.1 line” (e.g. v2.12.1. Cloned GitHub project and rebuilt gem for our nefarious purposes.)

rake manifest rake package rake install

add_joins! and Has Many Polymorphs (or anything else for that matter)

HMP includes a ‘tagged_with’ method for finding collections ‘tagged_with’ a set of tags. I use a heavily modified version of that. The method supports custom scopes, in theory. (well, probably more than theory, I’ve just never tried it). While, I don’t have any scopes on models that call my functions – I still had some of the private ActiveRecord method calls in mine – particularly add_joins!.

Well, this change changed the params for the method to make sure that the scoped joins were merged, and not overwritten – which changes calls into it. If you are calling it with your own options use options[:joins]. My code doesn’t use the scopes in combination with my tagged_with method, so I just pulled them.

And…. thankfully that’s it

Other than cleaning up deprecations like number_with_precision now preferring (number, :precision => myprecision) instead of (number, myprecision) – and ActiveRecord::Base.verification_timeout no longer valid, and mb_chars being preferred over chars – we seem to be good to go for Rails 2.2. I still need to test some crons, but I imagine that our app will go production as 2.2 shortly.

TOOOOOO-TOOOOOO-TOOOOOO!

Don’t Do That

So… maybe you are coding up your totally way rad awesome application in Rails – and you are thinking to yourself.

“Self, I really would like to set my own created_at and updated_at timestamps. Look – there’s even a way to do that in the Rails documentation

class Feed < ActiveRecord::Base self.record_timestamps = false # ... end

At this point you need to back away from the keyboard. Quickly. If you don’t, pretty soon, somewhere in your application – you are going to run into this error:

Mysql::Error: Column 'created_at' cannot be null

Or ALL KINDS OF OTHER FUN SIDE EFFECTS (FUN is actually a euphemism here for various four letter words)

See, record_timestamps is a class variable for ActiveRecord::Base created with the rails :cattr_accessor – maybe the self.record_timestamps should have tipped us all off – maybe not (there’s also a class_inheritable_accessor – I’m not sure where all that gets used though)

Even experienced developers not all that fluent in ruby minutiae (I think class variables count as minutiae) cut-and-paste first and figure out how it works second (yeah, don’t do that either).

So – anyway – once you change record_timestamps once – you change it for all descendants of ActiveRecord::Base

There’s a bit of discussion this on a separate, but related problem at Evan Weaver’s blog (pay special attention to that threading issue for those playing along with the home game). And of course, your friendly neighborhood reminder of what happens with class variables at Nic Williams’ blog (I recommend reading that twice and breaking out the home game version of irb)

So the moral of the story? self.record_timestamps – Don’t Do That.

p.s. Production of this blog entry was made possible through various grants and assessments, and with some moans, groans, sighs, and “what tha–?” from my colleagues James Robinson and Aaron Hundley (doesn’t have a blog, he needs to get with the program) 🙂

p.p.s edited to change “you chance it for all descendants…” to “you change it for all descendants” – I think the first one is quite apropos however