Module: OpenLogger

Defined in:
lib/logging/gem.logging.rb

Overview

MIXIN

magic is deployed to hand out DevOps quality logging

features to any class that includes the logging module.

When logging facilities are not ready we need to log just to stdout but when they are we need to use them.

mixin power enables one class to give the logfile path and all classes will suddenly retrieve a another logger and use that.

include Logging
def doImportant
  log.warn(x) "unhappy about doing this"
  do_anyway
  log.debug(x) "all good it was okay"
end

So what are Mixins?

Refer to the below link for excellent coverage of mixins.

See Also:

Constant Summary collapse

@@gem_name = 
"safedb.net"
@@gem_base = 
File.join OpenSession::Home.dir, ".#{@@gem_name}"
@@log_path = 
File.join @@gem_base, "safedb.net-cli.log"

Instance Method Summary collapse

Instance Method Details

#get_logger ⇒ Logger

This method returns an initialized logger.

The logger returned may write to

  • a simple file

  • a service like fluentd

  • a message queue

  • a nosql database

  • all of the above

Not that [memoization] should be used so that this method gets called ideally just once although in practise it may turn out to be a handful of times.



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# File 'lib/logging/gem.logging.rb', line 88

def get_logger

  file_logger = Logger.new @@log_path
  original_formatter = Logger::Formatter.new

  file_logger.formatter = proc { |severity, datetime, progname, msg|
    original_formatter.call( severity, datetime, progname, msg.dump.chomp.strip )
  }

  return file_logger

end

#log ⇒ Object

Classes that include (MIXIN) this logging module will have access to this logger method.

memoization

is implemented here for performance and

will only initiate a logger under 2 circumstances

[1] - the first call (returns a STDOUT logger)
[2] - the call after the logfile path is set
       (returns a more sophisticated logger)



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# File 'lib/logging/gem.logging.rb', line 42

def log

  @@log_class ||= get_logger

end

#nickname(object_path) ⇒ String

Overtly long file paths in the log files sometimes hamper readability and this method improves the situation by returning just the two immediate ancestors of the file (or folder) path.

So this method returns the name of the grandparent folder then parent folder and then the most significant file (or folder) name.

When this is not possible due to the filepath being colisively near the filesystem’s root, it returns the parameter name.

Examples:

A really long input like

<tt>/home/joe/project/degrees/math/2020</tt>
is reduced to
<tt>degrees/math/2020</tt>



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# File 'lib/logging/gem.logging.rb', line 119

def nickname object_path

  object_name   = File.basename object_path
  parent_folder = File.dirname  object_path
  parent_name   = File.basename parent_folder
  granny_folder = File.dirname  parent_folder
  granny_name   = File.basename granny_folder

  return [granny_name,parent_name,object_name].join("/")

end

#x ⇒ Object

This Ruby behavioural snippet allows the logger to print 3 crucial pieces of information for the troubleshooter (detective) so that they may ascertain

  • the [module] the logging call came from

  • the [method] the logging call came from

  • line number origins of the logging call

To use this method you can make calls like this

  • log.info(x) { “Log many things about where I am now.” }

  • log.warn(x) { “Log many things about where I am now.” }



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# File 'lib/logging/gem.logging.rb', line 62

def x

  module_name = File.basename caller_locations(1,1).first.absolute_path, ".rb"
  method_name = caller_locations(1,1).first.base_label
  line_number = caller_locations(1,1).first.lineno

  "#{module_name} | #{method_name} | (line #{line_number}) "

end