Ruby/on Rails

Linting violations

When running rubocop, style related linting violations are those that are flagged when running against Style, Layout and Lint cop departments.

rubocop --only Style,Layout,Lint

Complexity related linting violations are those that are non-style related:

rubocop --except Style,Layout,Lint

Local application profiling

Use rack-mini-profiler gem and ensure it’s only included in the :development bundler group for app.

Example Rack profiler configuration (config/initializers/rack_profiler.rb):

if Rails.env.development?
  require "rack-mini-profiler"


Application logging

  • Use remote_syslog_logger gem for the main application logging to Papertrail.
  • If using infrastructure setup specifically for project, use a log file and remote_syslog2 to capture, with:
    • 14 day retention
    • Daily rotation
  • Otherwise use PaaS integration with Papertrail to capture workers
    • Background workers confirmed to be logging
  • lograge gem installed and enabled for all non-development environments

Main application example configuration (for example, within config/environments/production.rb):

config.log_level = :info
config.logger ='', 12345, program: "rails-#{Rails.env}"))
config.log_tags = [:env, :subdomain, lambda { |r| r.cookies['_tpms_session'] }, :uuid]
config.log_formatter =
config.lograge.enabled = true

Background worker example configuration (config/initializers/delayed_job.rb):

Delayed::Worker.logger ='log', "jobs-#{Rails.env}.log"), 14, 'daily')

Exception tracking

Use the sentry-raven gem.

Additional data can be sent to Sentry when an exception is captured by using Raven.user_context. A simple integration with this is as following in ApplicationController.rb:

class ApplicationController < ActionController::Base
  before_action :set_raven_context

  def set_raven_context
    context = { request_uuid: request.uuid }


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