SimpleStructuredLogger

Dead-simple structured logging in ruby with a dead-simple codebase. That's it.

gem 'simple_structured_logger'

Design Goals

• Extremely simple codebase that's easy to read and override
• Structured logging that reads nicely
• Ability to easily set context, and expand context with user-configurable hook
• Ability to easily add structured log pre-processing. I want to be able to pass in an object specific to my application and for the relavent important keys to be expanded automatically.
• Rails.logger = SimpleStructuredLogger.new(STDOUT)
• Not designed around massive systems or scale
• Don't support multiple log destinations
• Don't build in fancy pre-processing for errors or other common ruby objects

Opinionated Devops Setup

• Errors are tracked using Rollbar, Airbrake, Sentry, etc.
• Log to STDOUT
• Pipe STDOUT to PaperTrail, Loggly, etc
• Great for Heroku or dokku/docker hosted system

Alternatives

• https://github.com/jordansissel/ruby-cabin
• https://github.com/asenchi/scrolls
• https://github.com/stripe/chalk-log
• https://github.com/nishidayuya/structured_logger
• https://github.com/rocketjob/semantic_logger

Why is structured logging important?

• https://engineering.linkedin.com/distributed-systems/log-what-every-software-engineer-should-know-about-real-time-datas-unifying
• http://juliusdavies.ca/logging.html

What about Rail's tagged logging?

Tagged logging is not structured logging. I want to be able to search through PaperTrail and easily grab an audit trail for a specific context, i.e. the_job=FailingJob the_user=1.

Usage

# config/initializers/logger.rb
if Rails.env.development? || Rails.env.test?
  SimpleStructuredLogger::Writer.instance.logger = Rails.logger
end

# models/order.rb
class Order
  include SimpleStructuredLogger

  def initialize
    log.reset_context!
    log.default_tags[:global] = 'key'
  end

  def do_something
    log.info 'simple structured logging', key: value, shopify_id: 123
  end
end

Testing

bundle exec rake