OpenShift::Runtime::NodeLogger

This class provides a central logging facility for all node operations.

The specific logger implementation used is created lazily upon first reference to logger. The logger implementation is obtained by reading the PLATFORM_LOG_CLASS key from +OpenShift::Config+, which is assumed to be the string name of the logger class to instantiate. The class is assumed to be in the +OpenShift::Runtime::NodeLogger+ module.

If no logger class is configured, the +OpenShift::Runtime::NodeLogger::SplitTraceLogger+ will be used by default.

Logger implementations are expected to confirm to the following simple interface:

module OpenShift
  module NodeLogger
    class CustomLogger
      def initialize(config, context); end

      def info(*args, &block); end
      def warn(*args, &block); end
      def error(*args, &block); end
      def fatal(*args, &block); end
      def debug(*args, &block); end
      def trace(*args, &block); end

      def reinitialize; end
    end
  end
end

NodeLogger maintains a context Hash which is passed to logger implementations. Callers may set and remove keys from the context at-will, to provide information such as transaction IDs or any other data which may be useful for loggers. The context object is NOT thread-safe.

A disable method is provided for convenience to initialize NodeLogger with the NullLogger, effectively disabling logging. This is equivalent to using external configuration, but provides a programmatic entrypoint.

Example:

require 'node_logger'

NodeLogger.logger.warn "A warning"
NodeLogger.logger.info { "A deferred-evaluation log message" }

NodeLogger.context[:tx_id] = 1234
NodeLogger.context.delete(:tx_id)

class MyClass
  include NodeLogger

  def fun
    logger.debug "A message"
  end
end