Heroku Memory Capitulator

Restart your Heroku application based on Heroku errors (e.g R14) indicating the app is in dire need of a restart.

• Environment variables
• Contents
  • Base system
  • General
  • Frontend
  • Development
  • Test
  • Production
• Removed
• Notes
  • Webpacker, the asset pipeline, and ES6
  • Custom classes
  • Gemfile.dev / Gemfile.dev.lock
  • Rack::RejectTrace middleware
  • Favicons

Environment variables

Variable	Comment
AIRBRAKE_PROJECT_ID	Used in config/initializers/airbrake.rb
AIRBRAKE_API_KEY	Used in config/initializers/airbrake.rb
BLOCK_HTTP_TRACE	Disables HTTP TRACE method if set to true/t/1
BUNDLE_GEMFILE	Useful when using a Gemfile.dev
DATABASE_URL	Used for production env, automatically set by Heroku
GOOGLE_ANALYTICS_ID	Will be added to the main application layout if set
HOST	Your base URI, e.g. https://myapp.herokuapp.com
NEW_RELIC_APP_NAME	Used in config/newrelic.yml
NEW_RELIC_LICENSE_KEY	Used in config/newrelic.yml
PORT	Port Puma will listen on, defaults to 3000
RAILS_LOG_TO_STDOUT	Set by Heroku Ruby buildpack, set manually on other platforms if needed
RAILS_MAX_THREADS	Number of Puma threads, defaults to 5
REDIS_URL	Used in config/cable.yml
WEB_CONCURRENCY	Number of Puma workers. We default to threads only, no workers

Contents

All of the following have been installed and pre-configured:

Base system

• Rails 5.2.0
• Ruby 2.5.1
• pg for ActiveRecord

General

• figaro
• foreman
• fast_jsonapi
• pundit
• sidekiq

Frontend

All of these are managed by yarn.

• bootstrap4
• jquery
• jquery-ujs
• popper.js

Development

• Brakeman
• bullet
• letter_opener
• memory_profiler
• newrelic_rpm
• nullalign
• pry
• pry-byebug
• pry-doc
• rack-mini-profiler
• RuboCop

Test

Rspec has been preconfigured for Rails 5.1+ system tests.

• No need to require 'rails_helper, we do it in .rspec
• bundler-audit (runs on CircleCI)
• capybara
• factory_bot_rails
• shoulda-matchers
• spring-commands-rspec
• webmock

Production

• airbrake
• heroku-deflater
• lograge
• rails_12factor
• rake-timeout
• secureheaders

Removed

The following default Rails gems have been removed:

• coffee-rails
• jbuilder

Notes

Webpacker, the asset pipeline, and ES6

By default ES6 will not work for files in app/assets/javascript since Uglifier will fail to process them. This is why we applied the following change to config/production.rb, which allows you to use ES6 project wide:

-  config.assets.js_compressor = :uglifier
+  config.assets.js_compressor = Uglifier.new(harmony: true)

Also note that for everything to work properly on Heroku, you need to set up your buildpacks like this:

heroku buildpacks:clear
heroku buildpacks:set heroku/nodejs
heroku buildpacks:add heroku/ruby

Custom classes

• ApplicationDecorator: lightweight alternative to Draper or similar gems.
• ApplicationForm: Minimal form class based on ActiveModel.
• ApplicationPresenter: a subclass of ApplicationDecorator for presenters, includes tag helpers.

All custom classes are fully documented with yard and come with generators.

Use yard doc to generate documentation and yard server --reload or yard server --gems to start a local documentation server.

Gemfile.dev / Gemfile.dev.lock

If you want to add specific gems for development that may not be interesting for other developers, you can add a Gemfile.dev (ignored by our .gitignore). Gems listed there can be installed with bundle install --gemfile Gemfile.dev and the resulting lock file is gitignored too.

Example Gemfile.dev:

source 'https://rubygems.org'

eval_gemfile 'Gemfile'

gem 'awesome_print'

The eval_gemfile line will ensure that all gems from your regular Gemfile will be included too. The BUNDLE_GEMFILE variable can be used to let Bundler now which gemfile to use:

BUNDLE_GEMFILE=Gemfile.dev rails c

Rack::RejectTrace middleware

There's a custom middleware (Rack::RejectTrace) for completely disabling the HTTP TRACE method as required by certain security audits. It can be enabled via the BLOCK_HTTP_TRACE environment variable.

Favicons

Favicons were generated with Real Favicon Generator, consider using the same tool when replacing them for your project.