Why am I getting an Application Error error page for my brand new app hosted by Heroku?

Question

I am pretty much brand new to RoR and such.

I am following a video tutorial to build my own web-based app, and I got to the step: git push heroku master

When in git bash, it was coming up with an error that claimed it couldn't compile ruby. Now, it says it is launched and deployed, but there is still the same error on the page for my app, http://infinite-mountain-6131.herokuapp.com/

Any ideas?? I can add files if needed.

Requested file(s):

app/config/application.rb from my comment

require File.expand_path('../boot', __FILE__)

require 'rails/all'

# config/application.rb
config.assets.initialize_on_precompile = false

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module Myrubyblog
  class Application < Rails::Application
    # Settings in config/environments/* take precedence over those specified here.
    # Application configuration should go into files in config/initializers
    # -- all .rb files in that directory are automatically loaded.

    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
    # config.time_zone = 'Central Time (US & Canada)'

    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
    # config.i18n.default_locale = :de
  end
end

Line 6 that was mentioned in my error is the config.assets.initialize which I put in there with line 5 as suggested to fix my problem.

This is what happens when I run the migrate as suggested (heroku run rake db:migrate)

Running 'rake db:migrate' attached to terminal... up, run.6274
rake aborted!
NameError: undefined local variable or method 'config' for main:Object
/app/config/application.rb:6:in '<top <required>>'
/app/Rakefile:4:in 'require'
/app/Rakefile:4:in '<top <required>'
<See full trace by running task with --trace>

Answer 1

As a rule, there are two types of error you can get when hosting a Rails app on Heroku:

Heroku Error

-

Rails Error

--

Error

The difference between the two is important - rails errors will only occur if your operating environment is actually "running" your Rails application. Heroku errors will occur if your operating environment / Heroku will not load correctly

The problem you have is definitely a Heroku issue - one which is typically created by a lack of db connectivity. The way to fix this issue is to ensure your application has all the necessities to run - most notably the correct db

You'll be best using the following:

$ heroku run rake db:migrate

However, I appreciate this won't be the only issue you'll have

---

Heroku Deployment

As you've said you're a "beginner" to ROR, let me give you some ideas

Firstly, when you write a question on here, it helps to divulge as much information as possible - typically from the logs, or any other specific error handling mechanism

Secondly, you want to ensure that everything required to get your application running has been achieved. Most notably, when you mention Heroku cannot compile the Ruby application , you'll need to provide information on why this is the case -- there'll probably be a gem conflict (SQLite3) or similar

Thirdly, you need to ensure you have migrated your database. This is the single biggest reason why "Heroku errors" appear - deploying your Rails app doesn't mean the migrations you made locally will persist - you need to ensure you have the db updated as you require, which can be done as follows:

$ heroku run rake db:migrate