Module: FilteredDebugLogger

Defined in:
lib/filtered_debug_logger.rb

Overview

Filter debug-level log entries on progname

Whilst well-thought-out debug logs are fantastic at showing you the fine-level detail of your program's execution, they can sometimes be "too much of a good thing". Excessively verbose debug logs can obscure the important debug info, and turning on debug logging on a busy service can quickly swamp all but the most overprovisioned of log aggregation systems.

Hence, there's this little module. Require it in your program, and then set logger.permitted_prognames = ['some', 'array'] on whatever logger is likely to want some debug logging. Then, whenever debug logging is enabled, only those calls to logger.debug which provide a progname exactly matching an entry in the list you provided will actually get logged.

Instance Method Summary collapse

Instance Method Details

#add(s, m = nil, p = nil) ⇒ Object Also known as: log

Decorate Logger#add with our "reject by progname" logic.



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# File 'lib/filtered_debug_logger.rb', line 33

def add(s, m = nil, p = nil)
  return if s == Logger::DEBUG && @permitted_prognames && !@permitted_prognames.include?(p)

  super
end

#permitted_prognames=(l) ⇒ Object

Set the list of prognames to log debug messages for.

Parameters:

  • l (Array<String>) —

    the (exact) prognames to log debug-level messages for. If it's not in this list, it doesn't get emitted, even if debug logging is enabled.

Raises:

  • (ArgumentError) 


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# File 'lib/filtered_debug_logger.rb', line 25

def permitted_prognames=(l)
  raise ArgumentError, "Must provide an array" unless l.is_a?(Array)

  @permitted_prognames = l
end