Some Notes Regarding Rsyslog and Remote Logging for Rails Apps
We use SyslogLogger gem in order to forward rails application log to system log.
in rails Gemfile:
group :production do gem "SyslogLogger", "~> 2.0", :require => 'syslog/logger' end
config.logger = Syslog::Logger.new "rails_application_name"
The problem was that logs actually were forwarded to syslog, messages and user.log and sent to remote server and written to syslog, messages and user.log there. I was asked to make things DRY(ier).
The issue was caused, of cource, by some nasty *.* patterns in rsyslog config. If you’re experiencing similar issues, check /etc/rsyslog.d directory which contains rsyslog configuration files. Make sure you have separate config file for your application and it has higher load priority, for example:
# ls -l -rw-r--r-- 1 root root 98 Jan 2 16:36 40-rails_application_name.conf -rw-r--r-- 1 root root 1605 Dec 10 2010 50-default.conf
rules in 40-rails_application_name.conf will be checked first. Contents of 40-rails_application_name.conf file on rails application server:
if $programname == 'rails_application_name' then @@your.logging.server.ip.com:61514 & ~
Note “& ~”, it means log entry will be sent using TCP to your.logging.server.ip.com:61514 and won’t be processed further. This was missing and entries were forwarded to local log files. If you do need to log to the local file, don’t add “& ~”.
rules in 40-rails_application_name.conf file on log server:
$ModLoad imtcp $InputTCPServerRun 61514 if $programname == 'rails_application_name' then /var/log/rails_application_name.log & ~
Now logs are stored correctly.
Here is a complete guide for those who needs more details regarding rsyslog configuration.