title: Facing issue `read': No such file or directory @ > rb_sysopen in rails
body: <p>Hello I have included given code in my 
  config/app_config.yml</p>
  
  <pre><code>development:
    name: mytest
    password: secret
  production:
    name: test
    password: Patest
  </code></pre>
  
  <p>config/application.rb</p>
  
  <pre><code>require File.expand_path('../boot', __FILE__)
  
  require 'rails/all'
  
  # Require the gems listed in Gemfile, including any gems
  # you've limited to :test, :development, or :production.
  Bundler.require(*Rails.groups)
  APP_CONFIG = YAML.load_file("#{::Rails.root}/config/app_config.yml")[::Rails.env]
  </code></pre>
  
  <p>app/controllers/application_controller.rb</p>
  
  <pre><code>http_basic_authenticate_with :name =&gt; APP_CONFIG[:name], :password =&gt; APP_CONFIG[:password]
  </code></pre>
  
  <p>Now when I run rails server it gives me following error ::</p>
  
  <blockquote>
    <p>config/application.rb:8:in <code>read': No such file or directory @
    rb_sysopen - /config/app_config.yml (Errno::ENOENT)   from
    /Users/rails_app/config/application.rb:8:in</code>'</p>
  </blockquote>
  
  <p>Please guide me what I am missing in my code how to solve this issue.</p>