====== Basic Kamailio (OpenSER) Logging ======

This is a way to setup syslog logging for Kamailio (OpenSER). This setup was based on Slackware 10.2, so your configuration may need to be modified for your distribution.

===== Configuration =====
==== Kamailio (OpenSER) Configuration ====

First, set these configuration options in your kamailio.cfg:

<code>
debug=3  # debug level, 1 is low and 4 is high (lots of output)
log_facility=LOG_LOCAL7

loadmodule "/usr/local/lib/kamailio/modules/xlog.so"
</code>

==== Syslog Configuration ====

Next, modify your syslog.conf (should be in /etc/syslog.conf), and add this line:

<code>
# Kamailio (OpenSER) messages, make sure this spacing is done with tabs, spaces may cause errors
local7.*                                            -/var/log/kamailio
</code>

Remarks:
  * the '-' before the name of the file means asynchronous writing, it is important to have it not to add performance penalty
  * if you don't want messages from Kamailio to /var/log/messages anymore, be sure you add local7.none to the line related to that file

Create the log file:

<code>touch /var/log/kamailio</code>

Now, in Kamailio (OpenSER), to do some custom logging within your route (it will still catch all regular output from Kamailio, of course), I like to use xlog. Regular log will work, too.

==== Extra Logging in Kamailio (OpenSER) ====

<code>
xlog("L_WARN", "Some message at level WARNING");
</code>

The first argument sets the level of the logging, and the next is the message.

===== Log Rotation =====

==== logrotate.conf ====

Within /etc/logrotate.conf, you can configure general paramters for your log rotation. My Slackware setup by default looks like this. 

<code>
# /etc/logrotate.conf
#
# logrotate is designed to ease administration of systems that generate large
# numbers of log files.  It allows automatic rotation, compression, removal, and
# mailing of log files.  Each log file may be handled daily, weekly, monthly, or
# when it grows too large.
#
# logrotate is normally run daily from root's crontab.
#
# For more details, see "man logrotate".

# rotate log files weekly:
weekly

# keep 4 weeks worth of backlogs:
rotate 4

# create new (empty) log files after rotating old ones:
create

# uncomment this if you want your log files compressed:
#compress

# some packages install log rotation information in this directory:
include /etc/logrotate.d

# Rotate /var/log/wtmp:
/var/log/wtmp {
    monthly
    create 0664 root utmp
    rotate 1
}

# Note that /var/log/lastlog is not rotated.  This is intentional, and it should
# not be.  The lastlog file is a database, and is also a sparse file that takes
# up much less space on the drive than it appears.

# system-specific logs may be also be configured below:
</code>


==== /etc/logrotate.d/kamailio ====

Each distribution may be different, but in Slackware 10.2, I created a the file /etc/logrotate.d/kamailio

I filled it with these parameters:

<code>
/var/log/kamailio {
    sharedscripts
    postrotate
	/bin/kill -HUP `cat /var/run/syslogd.pid 2>/dev/null` 2>/dev/null || true
    endscript
}
</code>

Finally, restart Kamailio (OpenSER) & syslog and enjoy!

Questions and corrections, please email to mikebwilliams@gmail.com, or feel free to correct this Wiki yourself.