customize logger messages in Rails2?

In Rails2, what's the best way to customize the format of logger output in Rails?

In Rails1, due to Rails weird monkey-patching of Logger, you couldn't just subclass Logger and then set it as the logger to be used. Has this been improved in Rails2, is there a cleaner way to do this now?

In Rails1, the only good way I found to customize the logger output was to myself monkey-patch Logger at the end of environment.rb, over-riding format_message:

class Logger   def format_message(severity, timestamp, progname, msg)     # stuff to output messages just the way I want.   end end

However, oddly, in Rails2 this seems to have stopped having any effect at all. The logger output is still uncustomized, Rails default.

Any advice? Thanks in advance to Frederick if he pays attention to this, because so far he's the only one who both understands what I'm talking about and pays attention to me :slight_smile: I already owe you many beverages of your choice, Frederick.

In Rails2, what's the best way to customize the format of logger
output in Rails?

In Rails1, due to Rails weird monkey-patching of Logger, you couldn't just subclass Logger and then set it as the logger to be used. Has
this been improved in Rails2, is there a cleaner way to do this now?

In Rails1, the only good way I found to customize the logger output
was to myself monkey-patch Logger at the end of environment.rb, over- riding format_message:

Well if you look at the source to BufferedLogger in rails 2, the add
method (which is what the rest of rails appears to be calling) just
appends the message to the buffer. (or in other words looks like you
should be overriding add on ActiveSupport::BufferedLogger or subclass
that and set config.logger to an instance of your subclass)

Fred

Yeah, thanks. I found this patch, which adds formatter functionality to BufferedLogger:

http://rails.lighthouseapp.com/projects/8994/tickets/1307-bufferedlogger-should-support-message-formatting

Using that as a guide, I have created a sub-class of BufferedLogger that does what I want, until/unless that makes it into a future Rails release.

But now I'm stuck figuring out how to tell Rails to use my new sub-class (or an instantiation of it) of a BufferedLogger. Nothing I try to do seems to work. Setting RAILS_DEFAULT_LOGGER myself to my instantiated logger in environment.rb, no. Setting config.logger to my instantiated logger in environment.rb, no.

Anyone figured out how to actually tell Rails2 to use a new logger object?

(Odd that it's taken so long to get logging right in Rails.)

Jonathan

Frederick Cheung wrote:

Yeah, thanks. I found this patch, which adds formatter functionality
to BufferedLogger:

#1307 BufferedLogger should support message formatting. - Ruby on Rails - rails

Using that as a guide, I have created a sub-class of BufferedLogger
that does what I want, until/unless that makes it into a future Rails release.

But now I'm stuck figuring out how to tell Rails to use my new sub- class (or an instantiation of it) of a BufferedLogger. Nothing I try to do seems to work. Setting RAILS_DEFAULT_LOGGER myself to my instantiated logger in environment.rb, no. Setting config.logger to my instantiated logger in environment.rb, no.

Anyone figured out how to actually tell Rails2 to use a new logger object?

I just set

config.logger = SyslogLogger.new 'rails' config.logger.level = Logger::INFO

from production.rb and that works fine.

Fred

Okay, I finally figured out how to get this to work. Leave this here for future list archive searchers, since I had to put together a bunch of pieces.

My custom logger, based on this patch: http://rails.lighthouseapp.com/projects/8994/tickets/1307-bufferedlogger-should-support-message-formatting

is in my lib/umlaut_logger.rb. So now that custom logger can take a formatter, like standard ruby Logger can.

For some reason, inside the environmental config block, auto-loading from constants doesn't seem to work yet, I needed to require_dependency it automatically. Then, I really wanted to take the existing log and severity level fields from RAILS_DEFAULT_LOGGER, but RAILS_DEFAULT_LOGGER isn't set yet here. But if I wait until it IS set, then it's too late for re-setting it to easily have an effect. So I had to reconstruct what it did from source, and other people's suggetsions in the listserv archives.

So, in the config block:

    require_dependency 'umlaut_logger'     severity_level = ActiveSupport::BufferedLogger.const_get(config.log_level.to_s.upcase)     log_file = File.join(RAILS_ROOT, "log", "#{RAILS_ENV}.log")

    our_logger = UmlautLogger.new(log_file, severity_level)     # eg, my real one is more complicated:     our_logger.formatter = lambda {|severity_label, message| "#{severity_label}: #{message}"}

    config.logger = our_logger

That was kind of a lot of work to get custom formatting. Phew.

Argh, this still isn't quite there yet. Now I can't start my app with script/console, which is convenient sometimes. Because in script/console, somehow ActiveSupport hasn't yet been loaded when it loads the environment.

So I had to add a "require 'active_support'" to my environment, and now console is happy. I hope that won't mess up anything else in the Rails load order.

I had no idea I'd have to get so much into the guts of Rails just to set a custom log format.

Jonathan Rochkind wrote:

I needed to blot out hugh binary data in the log so here's what I use in 2.1. I have a hard time believing that there's not a simpler way to blot out huge binary data but I've been unable to find it. I recall trying to use filter_parameter_logging from the controllers, but it didn't work for me at the time (likely my issue, not Rails). Anyhow this code shows one way to muck with the logger, maybe it'll help. It's in my environment.rb. Bananas not included.

module ActiveSupport   class BufferedLogger     def add(severity, message = nil, progname = nil, &block)       return if @level > severity       message = (message || (block && block.call) || progname).to_s       message.to_str.gsub!(/(\s|\()x'([0-9a-fA-F]*)'(,|\s|\))/,'\1x \'BINARY_DATA\'\3')

      level = {         0 => "D",         1 => "I",         2 => "W",         3 => "E",         4 => "F"       }[severity] || "U"

      message = "[%s: %s #%d] %s" % [level,                                      Time.now.strftime("%m%d %H:%M: %S"),                                      $$,                                      message]

      message = "#{message}\n" unless message[-1] == ?\n       buffer << message       auto_flush       message     end   end end