Disable IP address logging Rails - ruby-on-rails

Question

I am trying to disable logging of IP addresses while handling the request. But I am not able find a way to do this. I want to disable logging of IP for limited portion of my app where user is not yet authenticated.
So my questions is
How to disable logging of IP in rails log for specific pages(so the IP will not be saved in any log)
I am using Rails 3.2.17
EDIT:
Here is sample log (from environment.log)
Started GET "/my_path" for 192.168.0.109 at 2014-03-28 11:53:20 +0530
I do not want to save 192.168.0.109 in log file

Answer 1

In config/initializers, add file log_fomat.rb with:
class ActiveSupport::BufferedLogger
def formatter=(formatter)
#log.formatter = formatter
end
end
class Formatter
SEVERITY_TO_TAG_MAP = {'DEBUG'=>'meh', 'INFO'=>'fyi', 'WARN'=>'hmm', 'ERROR'=>'wtf', 'FATAL'=>'omg', 'UNKNOWN'=>'???'}
SEVERITY_TO_COLOR_MAP = {'DEBUG'=>'0;37', 'INFO'=>'32', 'WARN'=>'33', 'ERROR'=>'31', 'FATAL'=>'31', 'UNKNOWN'=>'37'}
USE_HUMOROUS_SEVERITIES = true
def call(severity, time, progname, msg)
if USE_HUMOROUS_SEVERITIES
formatted_severity = sprintf("%-3s","#{SEVERITY_TO_TAG_MAP[severity]}")
else
formatted_severity = sprintf("%-5s","#{severity}")
end
formatted_time = time.strftime("%Y-%m-%d %H:%M:%S.") << time.usec.to_s[0..2].rjust(3)
color = SEVERITY_TO_COLOR_MAP[severity]
"\033[0;37m#{formatted_time}\033[0m [\033[#{color}m#{formatted_severity}\033[0m] #{msg.strip} (pid:#{$$})\n"
end
end
Rails.logger.formatter = Formatter.new
References:
http://rubyjunky.com/cleaning-up-rails-4-production-logging.html
http://cbpowell.wordpress.com/2012/04/05/beautiful-logging-for-ruby-on-rails-3-2/
Rails logger format string configuration

Answer 2

Finally did this by using emaillenin's answer thanx emaillenin :D.
Here is solution
# Overriding Rails logger to not save IP addresses for specific paths
# Put this file in <app_root>/config/initializers
# defining setter for Rails default log formatter, so later we can set our custom logger using '='
class ActiveSupport::BufferedLogger
def formatter=(formatter)
#log.formatter = formatter
end
end
# Modified Formatter Class with custom 'call' method
class Formatter
Format = "%s\n"
# Remove IP while getting request on below specified Path
FilteredActionRegexp = /app_path|another_path/i
# reference for regexp of IP address
# http://answers.oreilly.com/topic/318-how-to-match-ipv4-addresses-with-regular-expressions/
IPRegexp = /\b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b/
FilteredString = '**FILTERED**'
def call(severity, time, progname, msg)
Format % [msg2str(filter_ip(msg))]
end
private
def msg2str(msg)
case msg
when ::String
msg
when ::Exception
"#{ msg.message } (#{ msg.class })\n" <<
(msg.backtrace || []).join("\n")
else
msg.inspect
end
end
# Replace IP Address with custom string if action is filtered
def filter_ip(msg)
# Replace only if message contains filtered action
if msg =~ FilteredActionRegexp
# If log string contains IP address then remove it with custom string
msg.gsub(IPRegexp, FilteredString )
else
msg
end
end
end
# Override Rails default logger formatter
Rails.logger.formatter = Formatter.new

Answer 3

I use Lograge
Taming Rails' Default Request Logging
Instead of having an unparsable amount of logging output like this:
Started GET "/" for 127.0.0.1 at 2012-03-10 14:28:14 +0100
Processing by HomeController#index as HTML
Rendered text template within layouts/application (0.0ms)
Rendered layouts/_assets.html.erb (2.0ms)
Rendered layouts/_top.html.erb (2.6ms)
Rendered layouts/_about.html.erb (0.3ms)
Rendered layouts/_google_analytics.html.erb (0.4ms)
Completed 200 OK in 79ms (Views: 78.8ms | ActiveRecord: 0.0ms)
you get a single line with all the important information, like this:
method=GET path=/jobs/833552.json format=json controller=jobs action=show status=200 duration=58.33 view=40.43 db=15.26