Logwatch Configuration in Linux

Logwatch is a modular log analyser that runs every night and mails you the results. It can also be run from command line.

The output is by service and you can limit the output to one particular service. The subscripts which are responsible for the output, mostly convert the raw log lines in structured format.

Logwatch generally ignores the time component in the output, that means, you will know that the reported event was logged in the requested range of time, but you will have to go to the raw log files to get the exact details.

Logwatch Installation in Debian

#apt-get install logwatch

That's it installation done.Now you need to configure the logwatch

Main Configuration file for logwatch located at /etc/logwatch/conf/logwatch.conf

Default Logwatch configuration file as below and you need to change this file options

# NOTE:

# All these options are the defaults if you run logwatch with no

# command-line arguments. You can override all of these on the

# command-line.

# You can put comments anywhere you want to. They are effective for the

# rest of the line.

# this is in the format of = . Whitespace at the beginning

# and end of the lines is removed. Whitespace before and after the = sign

# is removed. Everything is case *insensitive*.

# Yes = True = On = 1

# No = False = Off = 0

# Default Log Directory

# All log-files are assumed to be given relative to this directory.

LogDir = /var/log

# You can override the default temp directory (/tmp) here

TmpDir = /tmp

# Default person to mail reports to. Can be a local account or a

# complete email address.

MailTo = root

# If set to 'Yes', the report will be sent to stdout instead of being

# mailed to above person.

Print = No

# Leave this to 'Yes' if you have the mktemp program and it supports

# the '-d' option. Some older version of mktemp on pre-RH7.X did not

# support this option, so set this to no in that case and Logwatch will

# use internal temp directory creation that is (hopefully) just as secure

UseMkTemp = Yes

#

# Some systems have mktemp in a different place

#

MkTemp = /bin/mktemp

# if set, the results will be saved in instead of mailed

# or displayed.

#Save = /tmp/logwatch

# Use archives? If set to 'Yes', the archives of logfiles

# (i.e. /var/log/messages.1 or /var/log/messages.1.gz) will

# be searched in addition to the /var/log/messages file.

# This usually will not do much if your range is set to just

# 'Yesterday' or 'Today'... it is probably best used with

# Archives = Yes

# Range = All

# The default time range for the report...

# The current choices are All, Today, Yesterday

Range = yesterday

# The default detail level for the report.

# This can either be Low, Med, High or a number.

# Low = 0

# Med = 5

# High = 10

Detail = Med

# The 'Service' option expects either the name of a filter

# (in /etc/log.d/scripts/services/*) or 'All'.

# The default service(s) to report on. This should be left as All for

# most people.

Service = All

# You can also disable certain services (when specifying all)

#Service = -zz-fortune

# If you only cared about FTP messages, you could use these 2 lines

# instead of the above:

#Service = ftpd-messages # Processes ftpd messages in /var/log/messages

#Service = ftpd-xferlog # Processes ftpd messages in /var/log/xferlog

# Maybe you only wanted reports on PAM messages, then you would use:

#Service = pam_pwdb # PAM_pwdb messages - usually quite a bit

#Service = pam # General PAM messages... usually not many

# You can also choose to use the 'LogFile' option. This will cause

# logwatch to only analyze that one logfile.. for example:

#LogFile = messages

# will process /var/log/messages. This will run all the filters that

# process that logfile. This option is probably not too useful to

# most people. Setting 'Service' to 'All' above analyizes all LogFiles

# anyways...

#

# some systems have different locations for mailers

#

mailer = /usr/bin/mail

#

# With this option set to 'Yes', only log entries for this particular host

# (as returned by 'hostname' command) will be processed. The hostname

# can also be overridden on the commandline (with --hostname option). This

# can allow a log host to process only its own logs, or Logwatch can be

# run once per host included in the logfiles.

#

# The default is to report on all log entries, regardless of its source host.

# Note that some logfiles do not include host information and will not be

# influenced by this setting.

#

#HostLimit = Yes

Email Notifications With Logwatch

Logwatch is a slick Perl script that bundles up logfile reports and emails them to you. Debian users can install it by running apt-get install logwatch. Debian puts the configuration files in /etc/logwatch. The RPM puts them in /etc/log.d. Of course you may also install from sources. Be sure to consult the README for installation.

To make it go, first find logwatch.conf. You'll need to make a few tweaks. Set the "MailTo" directive to your desired email address, or local account. For local mail, most Linux systems still come with venerable old "mail", which works just fine:

MailTo = carla
mailer = /usr/bin/mail

Of course you may use any mailer you wish.

To make Logwatch send you daily reports, set the time range to "Today":

Range = Today

Other choices are "All" and "Yesterday." Now set your desired detail level for your reports:

Detail = High

Save your changes, and run Logwatch to send you a report:

# logwatch

The whole idea is to have Logwatch work without you having to exert yourself, so now you have to edit /etc/crontab to run Logwatch at your desired intervals. This runs it daily at 1am:

# m h dom mon dow user command
0 1 * * * root /usr/sbin/logwatch