[rsyslog-notify] Forum Thread: rsyslog filter /dev/null - (Mode 'post')

[noreply at adiscon.com]

User: davparker 
Forumlink: http://kb.monitorware.com/viewtopic.php?p=25582#p25582

Message: 
----------
Hello,

I'm creating a cetralized sylogger that collects syslog data from network
devices then forwards it to a Splunk server. I've got the basics working,
except that I'm getting an excessive number of messages from a switch that
I wish to discard. It seems simple enough, but my filter isn't working.
I've tried various combinations without success. No matter what I try, the
messages get forwarded. There is obviously something that I don't
understand about the way the filters operate. 

I wish to write all messages to /var/log/cisco/syslog and forward them to
the remote Splunk server that arrive on UDP Port 514, except for messages
that contain 'MACFLAP_NOTIF' events. The message string will contain
'MACFLAP_NOTIF' as well as  "flapping between".

the critical sectiom is:

# if $msg contains 'MACFLAP_NOTIF' then /dev/null
:msg, contains, "flapping between" ~
*.* @@net-siem-01:5140

Thanks

=========rsyslog.conf================

# rsyslog configuration file

# For more information see /usr/share/doc/rsyslog-*/rsyslog_conf.html
# If you experience problems, see <!-- m --><a class="postlink"
href="http://www.rsyslog.com/doc/troubleshoot.html">http://www.rsyslog.com/doc/troubleshoot.html</a><!--
m -->

#### MODULES ####

# The imjournal module bellow is now used as a message source instead of
imuxsock.
$ModLoad imuxsock # provides support for local system logging (e.g. via
logger command)
$ModLoad imjournal # provides access to the systemd journal
$ModLoad imklog # reads kernel messages (the same are read from journald)
$ModLoad immark  # provides --MARK-- message capability

# Provides UDP syslog reception
$ModLoad imudp
$UDPServerRun 514

# Provides TCP syslog reception
#$ModLoad imtcp
#$InputTCPServerRun 514

#### GLOBAL DIRECTIVES ####

# Where to place auxiliary files
$WorkDirectory /var/lib/rsyslog

# Use default timestamp format
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat

# File syncing capability is disabled by default. This feature is usually
not required,
# not useful and an extreme performance hit
#$ActionFileEnableSync on

# Include all config files in /etc/rsyslog.d/
$IncludeConfig /etc/rsyslog.d/*.conf

# Turn off message reception via local log socket;
# local messages are retrieved through imjournal now.
$OmitLocalLogging on

# File to store the position in the journal
$IMJournalStateFile imjournal.state

#### TEMPLATES ####

# Save Cisco log messages
$template RemoteHost,"/var/log/cisco/syslog"

#### RULESETS ####

# Local Logging
$RuleSet local

# Log all kernel messages to the console.
# Logging much else clutters up the screen.
kern.*                                                 /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none                /var/log/messages

# The authpriv file has restricted access.
authpriv.*                                              /var/log/secure

# Log all the mail messages in one place.
mail.*                                                  -/var/log/maillog

# Log cron stuff
cron.*                                                  /var/log/cron

# Everybody gets emergency messages
*.emerg                                                 :omusrmsg:*

# Save news errors of level crit and higher in a special file.
uucp,news.crit                                          /var/log/spooler

# Save boot messages also to boot.log
local7.*                                                /var/log/boot.log

# use the local RuleSet as default if not specified otherwise
$DefaultRuleset local

# ### begin forwarding rule ###
# The statement between the begin ... end define a SINGLE forwarding
# rule. They belong together, do NOT split them. If you create multiple
# forwarding rules, duplicate the whole block!
# Remote Logging (we use TCP for reliable delivery)
#
# An on-disk queue is created for this action. If the remote host is
# down, messages are spooled to disk and sent when it is up again.
# Remote syslog Splunk -> net-siem-01
$RuleSet remote
*.* ?RemoteHost

$ActionQueueFileName fwdNet   # unique name prefix for spool files
$ActionQueueMaxDiskSpace 1g   # 1gb space limit (use as much as possible)
$ActionQueueSaveOnShutdown on # save messages to disk on shutdown
$ActionQueueType LinkedList   # run asynchronously
$ActionResumeRetryCount -1    # infinite retries if host is down

# if $msg contains 'MACFLAP_NOTIF' then /dev/null
:msg, contains, "flapping between" ~
*.* @@net-siem-01:5140
# ### end of the forwarding rule ###

$InputUDPServerBindRuleset remote
$UDPServerRun 514