how to delete rails log file after certain size

Question

I have a daemon that runs constantly which fills up the log file(development.log or production.log) pretty quickly. What is the best way to delete the log file after certain

Answer 1

I prefer a monthly log file in my production.rb file

config.logger = Logger.new(config.log_path, 'monthly')

Answer 2

The best way is to set up log rotation, but how you do this is very platform dependent, so you should add a comment about what you're using, both for development and production.

For our apps running on Linux, we have a file /etc/logrotate.d/appname for each app, that looks something like this:

/path/to/rails_root_for_app/log/production.log {
    daily
    missingok
    rotate 7
    compress
    delaycompress
    notifempty
    create 640 capistrano capistrano
}

This will move the log into a new file once a day, keeping a compressed backup file for each of the last 7 days.

If you just want to empty the file without keeping any of the data in it while the daemon is running, simply do this from a shell:

> /path/to/rails_root_for_app/log/development.log

This will truncate the file to 0 bytes length.

Answer 3

Or you can delegate logging to syslog

Answer 4

config.logger = Logger.new(config.log_path, 50, 1.megabyte)

but beware that multiple mongrels can have issues with this.

Answer 5

Or even better, if all your environments are on either Mac or Linux, and have /usr/sbin/rotatelogs, just use that. It's much more flexible, and doesn't have the data loss issue that logrotate has (even if you use copytruncate).

Add this inside config/application.rb (or just config/environments/production.rb if you only want rotation in prod):

log_pipe = IO.popen("/usr/sbin/rotatelogs #{Rails.root}/log/#{Rails.env}.%Y%m%d.log 86400", 'a')
config.logger = Logger.new(log_pipe)

(From this blog post)