Question

I have 2 environments, production and staging, and I am using Capistrano with capistrano-ext gem.

When I deploy to staging using Capistrano and restart passenger, I would like the deployed application to run in staging however it runs in the default production

I tried setting:

set :rails_env, "staging"

in my deploy recipe, but this had no effect.

I am aware this can be done by setting a virtual host in Apache, but I am using shared hosting, so don’t have access. My host offers this advice:

add the following to environment.rb: ENV[‘RAILS_ENV’] = ‘staging’

but this doesn’t help me automate the process with Capistrano.

Answer 1

You can use a capistrano hook to create files on the server or symlink them in from e.g. shared/ when deploying.

For Rails 2.3:

On your web host, create the file shared/preinitializer.rb:

ENV['RAILS_ENV'] = 'staging'

Then add this to your Capfile (or possibly config/deploy.rb if you’re using a newer version of capistrano with Rails 2.x:

after 'deploy:symlink', 'localize:copy_shared_configurations'
namespace :localize do
  desc 'copy shared configurations to current'
  task :copy_shared_configurations, :roles => [:app] do
    # I put database.yml here to keep deployed db credentials out of git
    %w[
      preinitializer.rb
    ].each do |f|
      run "ln -nsf #{shared_path}/#{f} #{current_path}/config/#{f}"
    end
  end
end

For Rails 3

Due to the changes in Rails 3’s initialization sequence, config/preinitializer.rb is not loaded until after config/environment.rb is loaded. So for Rails 3, you want to modify config/environment.rb only on the server. You could do this with a similar setup like Rails 2 above, but using a symlinked copy of config/environment.rb, and adding the step of deleting the existing file before trying to symlink.

Another option would be to overwrite the environment.rb on the server from capistrano. In your config/deploy.rb:

after 'deploy:symlink', 'localize:munge_environment'
namespace :localize do
  desc 'munge environment.rb to set staging environment'
  task :munge_environment, :roles => [:app] do
    new_env = "ENV['RAILS_ENV'] = 'staging'\n" + File.read(Rails.root.join('config', 'environment.rb'))
    put new_env, "#{current_path}/config/environment.rb"
  end
end