DVLA::Herodotus

A Gem that produces loggers that are pre-formatted into an agreed log format

Installation

Add this line to your application's Gemfile:

gem 'dvla-herodotus'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install dvla-herodotus

Usage

Logger

You can get a logger by calling the following once Herodotus is installed:

logger = DVLA::Herodotus.logger

You can also provide the path to an output file, which will be logged to simultaneously with standard console logger

logger = DVLA::Herodotus.logger(output_path: 'logs.txt')

This is a standard Ruby logger, so anything that would work on a logger acquired the traditional way will also work here, however it is formatted such that all logs will be output in the following format:

[CurrentDate CurrentTime CorrelationId] Level : -- Message

Additionally, you can configure Herodotus in the following way to add a System Name and the Process Id to the output:

DVLA::Herodotus.configure do |config|
  config.system_name = 'SystemName'
  config.pid = true
end

This would result in logs in the following format:

[SystemName CurrentDate CurrentTime CorrelationId PID] Level : -- Message

Additionally, if you wish to have different correlation ids based on the scenario that is being currently being run, you can pass a unique identifier for your scenario as part of the logging call, with each scenario having a unique correlation id.

logger.info('String to log out', 'Scenario Id')

Alternatively, you can call new_scenario with the identifier just before each scenario to achieve the same result without having to pass the identifier around.

logger.new_scenario('Scenario Id')

Finally, you can set Herodotus up to integrate with any other instances of Herodotus that are loaded indirectly into your application, for example within a gem you use. To take advantage of this, when configuring Herodotus within your project, ensure that you set its merge value to true, as below:

DVLA::Herodotus.configure do |config|
  config.merge = true
end

This will cause your correlation ids to be shared out with all the loggers that exist outside of our direct control. The instance of the Herodotus that will take precedence will be the last one to be loaded, which should be the one you are creating with DVLA::Herodotus.logger.

Strings

Also included is a series of additional methods on String that allow you to modify the colour and style of logs. As these exist on String, you can call them on any string such as:

example_string = 'Multicoloured String'.blue.bg_red.bold

Method	Function
blue	Sets the string's colour to blue
red	Sets the string's colour to red
green	Sets the string's colour to green
brown	Sets the string's colour to brown
blue	Sets the string's colour to blue
magenta	Sets the string's colour to magenta
cyan	Sets the string's colour to cyan
gray	Sets the string's colour to gray
bg_blue	Sets the string's background colour to blue
bg_red	Sets the string's background colour to red
bg_green	Sets the string's background colour to green
bg_brown	Sets the string's background colour to brown
bg_blue	Sets the string's background colour to blue
bg_magenta	Sets the string's background colour to magenta
bg_cyan	Sets the string's background colour to cyan
bg_gray	Sets the string's background colour to gray
bold	Sets the string to be bold
italic	Sets the string to be italic
underline	Sets the string to be underline
blink	Sets the string to blink
reverse_color	Reverses the colour of the string

Development

Herodotus is very lightweight. Currently all code to generate a new logger can be found in herodotus.rb and the code for the logger is in herodotus_logger.rb so that is the best place to start with any modifications