Set logging levels in Ruby on Rails

Question

I'm using following code to configure logging in my Ruby on Rails application:

environment.rb:

Rails.logger = Logger.new(STDOUT)

class Logger
  def format_message(severity, timestamp, progname, msg)
    "#{timestamp.to_formatted_s(:db)} #{severity} #{msg}\n"
  end
end

I'm trying to set the logging level to warn now using

config.log_level = :warn

in my production.rb, but it doens't seem to work. Am I missing something here?

If I put Rails.logger.level = 4 in my environment.rb, it does seem to work. But I would like to configure things in my environment initializers.

Answer 1

According to the official documentation, you should be using:

config.log_level = :warn # In any environment initializer, or
Rails.logger.level = 0 # at any time

If neither of those work for you, try:

config.log_level = Logger::WARN

And if that doesn't work, try:

config.logger.level = Logger::WARN

Note: The final method appears to be conflating the two official strategies, but works in some situations

Answer 2

For Rails 4.0 you can set the value in production.rb (or your desired environment) like so:

# Set to :debug to see everything in the log.
config.log_level = :warn

Update The docs state it like so:

2.2 Log Levels

When something is logged it's printed into the corresponding log if the log level of the message is equal or higher than the configured log level. If you want to know the current log level you can call the Rails.logger.level method.

The available log levels are: :debug, :info, :warn, :error, :fatal, and :unknown, corresponding to the log level numbers from 0 up to 5 respectively. To change the default log level, use

config.log_level = :warn # In any environment initializer, or
Rails.logger.level = 0 # at any time

This is useful when you want to log under development or staging, but you don't want to flood your production log with unnecessary information.

The default Rails log level is info in production mode and debug in development and test mode.