diagnostics.md

Diagnostics

Shipping apps to a production environment is paramount in our development cycle. Having the correct tools in place to monitor and diagnose issues is essential.

The following is the baseline setup for logging and error tracking in Rails applications at DVELP.

Naming

Make sure you have the same names for Heroku application, sentry project and papertrail system e.g. dvelp-production. Consistency in naming conventions is very important.

Logging

Papertrail

For consistency and consolidation, we use a corporate Papertrail account for logging purposes.

Setup

This guide will help you get Papertail set up on Heroku environments.

Lograge

To prevent overly verbose logs, we recommend using lograge to filter out the noise and provide more clarity.

# config/initializers/lograge.rb

Rails.application.configure do
  config.lograge.enabled = Rails.env.production?
  config.lograge.custom_options = lambda do |event|
    exceptions = %w[controller action format]
    {
      params: event.payload[:params].except(*exceptions)
    }
  end
end

If you’re using Rails 5's API-only mode and inherit from ActionController::API, you must define it as the controller base class which lograge will patch:

config.lograge.base_controller_class = 'ActionController::API'

Use info log level to remove unnecessary debugging logs.

# config/environments/production.rb

config.log_level = :info

Error Handling

We equally have a corporate Sentry account for error handling. Sentry is a service designed to help you monitor application issues in realtime.

Setup

Complete the following steps to setup Sentry in your application:

• Create new project on the DVELP corporate account
• Add gem 'sentry-raven' to your Gemfile and run bundle install
• Set SENTRY_DSN ENV variable. Sentry will give you this when creating a new project (step 1).
• Set SENTRY_ENVIRONMENT ENV variable accordingly.

To make sure your application doesn't send any confidential information like passwords, set sanitize fields:

# config/initializers/sentry.rb

Raven.configure do |config|
  config.sanitize_fields = Rails.application.config
    .filter_parameters.map(&:to_s)
  config.current_environment = ENV.fetch('SENTRY_ENVIRONMENT', 'production')
end

Also, the last config line allows you to set the proper environment to your Sentry project.

Testing

To send a test event after setting up Sentry in your application, run the following command:

rails raven:test

And for Heroku:

heroku run rails raven:test --remote <git_remote>

Slack integration

Don't forget to add notifications to your project Slack channel. To enable this feature go to Sentry project settings and choose 'Alerts' section.