ruby on rails - Error pushing to heroku - aborting my rake assets:precompile

Question

Edit: I'm a new ruby on rails student.

Following my Git Push Heroku Master, I am running into issues with Heroku. Here is the latest and greatest, aborting the rake assets:precompile.

-----> Preparing app for Rails asset pipeline
   Running: rake assets:precompile
   rake aborted!
   could not connect to server: Connection refused
   Is the server running on host "127.0.0.1" and accepting
   TCP/IP connections on port 5432?
   Tasks: TOP => environment
   (See full trace by running task with --trace)
   Precompiling assets failed, enabling runtime asset compilation
   Injecting rails31_enable_runtime_asset_compilation
   Please see this article for troubleshooting help:
   http://devcenter.heroku.com/articles/rails31_heroku_cedar#troubleshooting

Included below are the contents of my Gemfile:

gem 'rails', '3.2.8'
gem 'bootstrap-sass', '2.1'
gem 'pg'

group :development, :test do
  gem 'rspec-rails'
  gem 'guard-rspec'
  gem 'guard-spork'
  gem 'spork'
  gem 'annotate'
  gem 'database_cleaner'
end

# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails',   '~> 3.2.3'
end

platforms :jruby do
  gem 'trinidad'
  gem 'jruby-openssl'
end

gem 'jquery-rails'

# Use unicorn as the web server
# gem 'unicorn'

# Deploy with Capistrano
# gem 'capistrano'

# To use debugger
# gem 'ruby-debug'

# Bundle the extra gems:
gem 'RedCloth', '~> 4.2.9', :require => 'redcloth'
gem 'ruby-openid', :require => 'openid'
gem 'rack-openid', :require => 'rack/openid'
gem 'aaronh-chronic', :require => 'chronic' # Fixes for 1.9.2
gem 'coderay'
gem 'lesstile'
gem 'formtastic'
gem 'will_paginate', '~> 3.0.2'
gem 'exception_notification', '~> 2.5.2'
gem 'open_id_authentication'

# Bundle gems for the local environment. Make sure to
# put test-only gems in this group so their generators
# and rake tasks are available in development mode:
group :test do
  gem 'database_cleaner'
  gem 'cucumber-rails',    :require => false
  gem 'cucumber-websteps', :require => false
  gem 'factory_girl'
  gem 'rspec'
  gem 'nokogiri', '~> 1.5.0'
  gem 'webrat'
end

What might be the issue?

Update: I ran the rake command with --trace, and it had alerted me with a failure because the production database did not exist. I created the database, and ran --trace again, and this is what I'm currently being thrown:

Command failed with status (1): [/usr/local/Cellar/ruby/1.9.3-p286/bin/ruby...]

Answer 1

See the Rails 3.1+ Asset Pipeline on Heroku Cedar article. This exact scenario is covered in the Troubleshooting section.

In short, your Heroku application has a strong separation between building (including asset compilation) and running (where your application becomes available). This is consistent with the 12-factor app principles, but it means that your application cannot access any configured resources during the build phase -- including the database -- meaning ActiveRecord is unavailable during asset precompilation.

You can tell Rails not to bootstrap your application during asset compilation in config/application.rb:

config.assets.initialize_on_precompile = false

The troubleshooting section also recommends:

If rake assets:precompile is still not working, you can debug this locally by configuring a nonexistent database in your local config/database.yml and attempting to run rake assets:precompile. Ideally you should be able to run this command without connecting to the database.