Fredclo at 11:36, 12 May 2019

2019-05-12T11:36:58Z

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=Purpose=

In this page, we will describe how to make Domoticz log to syslog. In this case it is set up to use ''rsyslog''. Other syslog implementation should be very similar.

The purpose of this is to be able to send the Domoticz log to other systems for remote logging, be able to separate the Domoticz log into separate syslog facilities/logfiles and/or consolidate the logs from several Domoticz instances on a shared loghost.

= Preparations =

For this setup, you will need to use a version of Domoticz that supports selecting the syslog facility to be used. The help text indicating this is supported is:

$ ./domoticz -h
2016-03-09 20:18:17.747 Domoticz <span style="color: red;">V3.4933</span> (c)2012-2016 GizMoCuz
2016-03-09 20:18:17.894 Build Hash: e404b11, Date: 2016-03-09 17:30:00
.
. (lines deleted)
.
-syslog <span style="color: red;">[user|daemon|local0 .. local7]</span> (use syslog as log output, defaults to facility 'user')

Versions before this will log to syslog faciliity ''user'' (a.k.a. LOG_USER), which is still the default if no argument is provided

Syslog facilities are message properties that can be used in your <tt>/etc/rsyslog.conf</tt> file to determine how to further route the messages into files and/or relay messages to remote syslog servers.

= Setup procedure =

'''Change the DAEMON_ARGS'''

You will need to edit <tt>/etc/init.d/domoticz.sh</tt> and make the ''DAEMON_ARGS'' include at least:

DAEMON_ARGS="-loglevel normal -syslog local1 -daemon -www .........."

Where the Domoticz log level and syslog facility is your choice.

'''Set up a dedicated syslog logfile for Domoticz'''

This an optional step, You may want to supplement the above ''local1'' log facility with a separate syslog file. For rsyslog, that can be set up as follows in <tt>/etc/rsyslog.conf</tt>

user.info -/var/log/user.log
local0.info -/var/log/local0.log
local1.info -/var/log/local1.log
local2.info -/var/log/local2.log

If you want to send the same to a remote system, use an ip address or hostname, or more commonly a ''loghost'' alias, as follows:

user.info @@loghost
local0.info @loghost
local1.info @loghost
local2.info @192.168.5.100

The first entry will log using a TCP connection (more modern syslog implementations), the other will use UDP datagrams (legacy) for the message protocol transport

'''Restart services'''

You can now restart Domoticz and rsyslog
sudo service rsyslog restart
sudo service domoticz.sh restart

Then make sure that the logfiles update:
tail -f /var/log/local1.log

'''Set up log rotation'''

If your /var/log filesystem is small, you will want to set up log rotation as well. In Raspian and many other Linux distros, the ''logrotate'' utility runs from a daily cron job (ref <tt>/etc/cron.daily/logrotate</tt>)

A suggested setup can be set up by creating a <tt>/etc/logrotate.d/local</tt> configuration file containing the following:
/var/log/local*.log
{
rotate 4
weekly
maxsize 64M
missingok
notifempty
compress
delaycompress
sharedscripts
postrotate
invoke-rc.d rsyslog rotate > /dev/null
endscript
}

Refer to <tt>man logrotate</tt> for an explanation of the semantics of this.

= References =

Take care if you use a SD card for the <tt>/var/log</tt> files. Logging a lot will likely make the SD card fail over time.

Consider to use tmpfs or look into [[Setting up overlayFS on Raspberry Pi]] instead

[[Category:Domoticz]]
[[Category:Manual]]
[[Category:Linux]]
[[Category:Raspberry Pi]]

Set up Domoticz to syslog - Revision history

Fredclo at 11:36, 12 May 2019