Hehe ...The idea of Log4r comes from the famous "Log4j", which is my favorite logger in my java programming life.
However log4r's doc is really poor, and it's really hard for newbies. Let me show my solution:
Step1. create the log4r config file: (file name: config/log4r.yml)
log4r_config:
# define all loggers ...
loggers:
- name : production
level : WARN
trace : 'false'
outputters :
- datefile
- name : development
level : DEBUG
trace : 'true'
outputters :
- datefile
# define all outputters (incl. formatters)
outputters:
- type: DateFileOutputter
name: datefile
dirname: "log"
# notice the file extension is needed!
# if you want the file is named by the process, just comment it,
# then it will automatically get the same name with its process,
# e.g. rails_2017-05-03.log
filename: "my_app.log"
formatter:
date_pattern: '%H:%M:%S'
pattern : '%d %l: %m '
type : PatternFormatter
step2. modify config/application.rb
require 'rails/all'
# add these line for log4r
require 'log4r'
require 'log4r/yamlconfigurator'
require 'log4r/outputter/datefileoutputter'
include Log4r
Bundler.require(:default, Rails.env) if defined?(Bundler)
module Zurich
class Application < Rails::Application
#...
# assign log4r's logger as rails' logger.
log4r_config= YAML.load_file(File.join(File.dirname(__FILE__),"log4r.yml"))
YamlConfigurator.decode_yaml( log4r_config['log4r_config'] )
config.logger = Log4r::Logger[Rails.env]
end
end
step3. add this line to your Gemfile.
# which is the latest version and support "datefileoutputter"
gem 'log4r', '1.1.9'
(if you are using Rails 4+ (including Rails6), there still is step4: add this file to config/initializers folder
# config/initializers/log4r_patch_for_rails4.rb
class Log4r::Logger
def formatter() # for rails4+
Proc.new{|severity, time, progname, msg|
formatted_severity = sprintf("%-5s",severity.to_s)
formatted_time = time.strftime("%Y-%m-%d %H:%M:%S")
"[#{formatted_severity} #{formatted_time} #{$$}]
#{msg}
"
}
end
def formatter= temp # for rails6+
end
end
)
It's done. Now "cd" into your Rails application folder, run "bundle" to install log4r, then "rails s",
you will find the log files in "/log" folder like this:
May 9 17:05 rails_2011-05-09.log
May 10 13:42 rails_2011-05-10.log
and the log content is( my favorite format ) :
$ tail log/rails_2011-05-10.log
Started GET "/????_settings/19/edit" for 127.0.0.1 at ...
13:42:11 INFO: Processing by ????SettingsController ...
13:42:11 INFO: Parameters: {"id"=>"19"}
13:42:12 DEBUG: ????Setting Load (0.0ms) SELECT "d ...
13:42:12 INFO: Completed 200 OK in 750ms
My environment:
- OS: cygwin running in XP
- ruby 1.8.7 (2011-02-18 patchlevel 334) [i386-mingw32]
- rails: 3.0.5
- gem: 1.6.0
Any question please let me know~ :-)
refer to: https://stackoverflow.com/a/20154414/445908
,and rails6 log4r tagged_logging.rb:22:in `call': wrong number of arguments
