First, make sure you are running a recent Ruby version. You need at least Ruby 1.8.7, if you still prefer the 1.8 series. So if you are running Leopard with the default Ruby installation, you are out of luck. Anyways it is recommended to switch to Ruby 1.9.1-p376. For an easy way to switch Ruby installations, try RVM.
Getting Rails 3
That’s the easy part. Just clone the official Rails git repository, including submodules:
git clone git://github.com/rails/rails.git --recursive
Congratulations! You now have a working Rails 3 installation!
Creating an application
What’s the use of having Rails 3 without creating a new application? So we just go for it!
First, step out of your Rails 3 directory:
Then, create a new project:
ruby rails/railties/bin/rails awesome_project
If you are using .git, create this .gitignore file:
.DS_Store .rake_tasks~ config/database.yml doc/api log/*.log tmp/**/* db/*.sqlite3 bin/* vendor/gems/* !vendor/gems/cache/
Then commit the first version of the project:
cd awesome_project mate .gitignore # insert the stuff from above git init git add . git ci -am "initial commit"`
Next, we have to bundle some gems. Unfortunately, the default Rails
Gemfile is not any good, so we will have to replace it with something
more useful like this:
Delete or comment out existing content and insert the following lines:
gem "arel", "0.2.pre", :git => "git://github.com/rails/arel.git" gem "rack", "1.1.0", :git => "git://github.com/rails/rack.git" gem "rails", "3.0.pre", :git => "git://github.com/rails/rails.git"
Then we run bundler:
After that, you should have a fully working Rails 3.0.pre installation.
Try the following command to see if everything works for you:
rake -T script/console script/server
If everything is working fine, think about the next steps. For example,
you are probably going to need a database adapter, so it’s certainly a
good idea to bundle that.
UPDATE: If you want to check out an application that is exactly that
far, you can check out my Rails 3 sample
Have fun using Rails 3.0.pre!