Class: Syslog::Logger

Inherits:
Object
  • Object
show all
Defined in:
lib/syslog/logger.rb,
lib/syslog/logger/version.rb

Overview

Syslog::Logger is a Logger work-alike that logs via syslog instead of to a file. You can use Syslog::Logger to aggregate logs between multiple machines.

By default, Syslog::Logger uses the program name ‘ruby’, but this can be changed via the first argument to Syslog::Logger.new.

NOTE! You can only set the Syslog::Logger program name when you initialize Syslog::Logger for the first time. This is a limitation of the way Syslog::Logger uses syslog (and in some ways, a limitation of the way syslog(3) works). Attempts to change Syslog::Logger’s program name after the first initialization will be ignored.

Example

The following will log to syslogd on your local machine:

require 'syslog/logger'

log = Syslog::Logger.new 'my_program'
log.info 'this line will be logged via syslog(3)'

You may need to perform some syslog.conf setup first. For a BSD machine add the following lines to /etc/syslog.conf:

!my_program
*.*                                             /var/log/my_program.log

Then touch /var/log/my_program.log and signal syslogd with a HUP (killall -HUP syslogd, on FreeBSD).

If you wish to have logs automatically roll over and archive, see the newsyslog.conf(5) and newsyslog(8) man pages.

Constant Summary collapse

VERSION =

The version of Syslog::Logger you are using.

'2.0'
LEVEL_MAP =

Maps Logger warning types to syslog(3) warning types.

Messages from ruby applications are not considered as critical as messages from other system daemons using syslog(3), so most messages are reduced by one level. For example, a fatal message for ruby’s Logger is considered an error for syslog(3).

{
  ::Logger::UNKNOWN => Syslog::LOG_ALERT,
  ::Logger::FATAL   => Syslog::LOG_ERR,
  ::Logger::ERROR   => Syslog::LOG_WARNING,
  ::Logger::WARN    => Syslog::LOG_NOTICE,
  ::Logger::INFO    => Syslog::LOG_INFO,
  ::Logger::DEBUG   => Syslog::LOG_DEBUG,
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(program_name = 'ruby') ⇒ Logger

Fills in variables for Logger compatibility. If this is the first instance of Syslog::Logger, program_name may be set to change the logged program name.

Due to the way syslog works, only one program name may be chosen.



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# File 'lib/syslog/logger.rb', line 146

def initialize program_name = 'ruby'
  @level = ::Logger::DEBUG

  @@syslog ||= Syslog.open(program_name)
end

Instance Attribute Details

#level ⇒ Object

Log level for Logger compatibility.



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# File 'lib/syslog/logger.rb', line 137

def level
  @level
end

Class Method Details

.make_methods(meth) ⇒ Object

Builds a methods for level meth.



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# File 'lib/syslog/logger.rb', line 81

def self.make_methods meth
  level = ::Logger.const_get(meth.upcase)
  eval <<-EOM, nil, __FILE__, __LINE__ + 1
    def #{meth}(message = nil, &block)
      add(#{level}, message, &block)
    end

    def #{meth}?
      @level <= #{level}
    end
  EOM
end

.syslog ⇒ Object

Returns the internal Syslog object that is initialized when the first instance is created.



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# File 'lib/syslog/logger.rb', line 67

def self.syslog
  @@syslog
end

.syslog=(syslog) ⇒ Object

Specifies the internal Syslog object to be used.



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# File 'lib/syslog/logger.rb', line 74

def self.syslog= syslog
  @@syslog = syslog
end

Instance Method Details

#add(severity, message = nil, progname = nil, &block) ⇒ Object

Almost duplicates Logger#add. progname is ignored.



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# File 'lib/syslog/logger.rb', line 155

def add severity, message = nil, progname = nil, &block
  severity ||= ::Logger::UNKNOWN
  @level <= severity and
    @@syslog.log LEVEL_MAP[severity], '%s', clean(message || block.call)
  true
end

#severity ⇒ Object

:method: debug

Logs a message at the debug (syslog debug) log level, or logs the message returned from the block.



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# File 'lib/syslog/logger.rb', line 130

Logger::Severity::constants.each do |severity|
  make_methods severity.downcase
end