This chapter describes the operating system prerequisits installation, needed to get the plugin running.
To quickly install all the requirements, just execute the following:
Red Hat flavor
# yum install net-snmp net-snmp-utils sudo perl perl-Config-General perl-Data-Dumper perl-Getopt-Long perl-Sort-Naturally perl-Exception-Class perl-Time-HiRes
Debian flavor
# apt-get install snmpd sudo perl libconfig-general-perl libdata-dumper-simple-perl libsort-naturally-perl libexception-class-perl libencode-perl
- Net-snmp software
The snmpwalk command must be available on your operating system.
If not, install the following:
Red Hat flavor
# yum install net-snmp net-snmp-utils
Debian flavor
# apt-get install snmpd
Test your snmpwalk output with a command like:
# snmpwalk -Oqn -v 1 -c public myrouter | head
.1.3.6.1.2.1.1.1.0 Cisco IOS Software, 2174 Software Version 11.7(3c), REL.
SOFTWARE (fc2)Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2005 by Cisco Systems, Inc.
Compiled Mon 22-Oct-03 9:46 by antonio
.1.3.6.1.2.1.1.2.0 .1.3.6.1.4.1.9.1.620
.1.3.6.1.2.1.1.3.0 9:11:09:19.48
snmpwalk parameters: -Oqn -v 1 : some noise (please read "man snmpwalk"). Change to -Oqn -v2c to check the access via SNMPv2 -c public : snmp community string myrouter : host where you do the snmp queries
snmpwalk is part of the net-snmp suite (http://net-snmp.sourceforge.net/
). Some more unix commands to find it:
Snmpwalk binary location:
snoopy:~# which snmpwalk
/usr/bin/snmpwalk
Net-Snmp installed version:
snoopy:~# snmpwalk -V
NET-SNMP version: 5.4.3
Note: Since Net-Snmp v5.4.2.1, the package libsnmp-base doesn't provide the same amont of mibs as before. Anyone who want to use keywords like 'system' or 'interfaces'� need to install the package 'snmp-mibs-downloader'�, and uncomment 'mibs :'� in /etc/snmp/snmp.conf
- Sudo software
Sudo is used to allow the www/apache user to reset the state files, i.e to remove some files generated by the plugin on the server.
To install:
Red Hat flavor
# yum install sudo
Debian flavor
# apt-get install sudo
- PERL v5
You need a working perl 5.x installation. The plugin has been successfully tested with perl >= 5.8.8, but should work with previous versions.
Get your perl version with:
snoopy:~# perl -V | head -1
Summary of my perl5 (revision 5 version 10 subversion 1) configuration:
If not installed, do the following:
Red Hat flavor
# yum install perl
Debian flavor
# apt-get install perl
To find out if a specific perl module is installed, execute the following from the command line:
perl -MModuleName -e 1
If you don't get any output from the above command then the module is installed. If you get an error, it's not installed. Example:
[root@snoopy ~]# perl -MEncode -e 1
[root@snoopy ~]#
[root@snoopy ~]# perl -MNotInstalledModule -e 1
Can't locate NotInstalledModule.pm in @INC (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .).
BEGIN failed--compilation aborted.
[root@snoopy ~]#
- Net-SNMP library
Net-SNMP is the perl's snmp library. Some ideas to see if it is installed:
For RedHat, Fedora, SuSe:
# rpm -qa|grep -i perl|grep -i snmp
perl-Net-SNMP-5.2.0-12.2
# find /usr -name SNMP.pm
/usr/lib/perl5/vendor\_perl/5.8.8/Net/SNMP.pm
if it is not installed please check your operating systems packages or install it from CPAN: http://search.cpan.org/search?query=Net%3A%3ASNMP&mode=all
- Config-General library
Config-General is used to write all interface information data back to the file system.
This perl library should be available via the package management tool of your system distribution.
Red Hat flavor
# yum install perl-Config-General
Debian flavor
# apt-get install libconfig-general-perl
CPAN page: http://search.cpan.org/search?query=Config%3A%3AGeneral&mode=all
- Data-Dumper library
Data-Dumper is used to easily dump hashes and arrays in some parts of the debug.
This perl library should be available via the package management tool of your system distribution.
Red Hat flavor
# yum install perl-Data-Dumper
Debian flavor
# apt-get install libdata-dumper-simple-perl
CPAN page: http://search.cpan.org/search?query=Data%3A%3ADumper&mode=all
- Getopt-Long library
Getopt-Long is used to handle the commandline options of the plugin.
This perl library should already be available on your system.
Red Hat flavor
# yum install perl-Getopt-Long
Debian flavor
Provided with the core perl package
CPAN page: http://search.cpan.org/search?query=Getopt%3A%3ALong&mode=all
- CGI library
CGI is used to handle Common Gateway Interface requests and responses. Note: with RedHat/CentOS 7.x you need to install a package:
To install:
Red Hat flavor
# yum install perl-Sort-Naturally
This library is included in the Perl doftware distribution, and should be available on your system.
- Sort-Naturally library
Sort-Naturally is used to sort arrays in a more natural order.
To install:
Red Hat flavor
# yum install perl-Sort-Naturally
Debian flavor
# apt-get install libsort-naturally-perl
CPAN page: http://search.cpan.org/~bingos/Sort-Naturally-1.03/lib/Sort/Naturally.pm
- Exception-Class library
Exception-Class is used to throw exceptions from functions.
To install:
Red Hat flavor
# yum install perl-Exception-Class
Debian flavor
# apt-get install libexception-class-perl
CPAN page: http://search.cpan.org/~drolsky/Exception-Class-1.37/lib/Exception/Class.pm
- Time-HiRes library
Time-HiRes is used for high resolution timers.
To install:
Red Hat flavor
# yum install perl-Time-HiRes
Debian flavor
Provided with the core perl package
CPAN page: http://search.cpan.org/~zefram/Time-HiRes-1.9725/HiRes.pm
- Encode library
Encode consists of a collection of modules for character encoding/decoding.
This perl library may already be available on your system.
Red Hat flavor
Provided with the core perl package
Debian flavor
# apt-get install libencode-perl
CPAN page: http://search.cpan.org/~dankogai/Encode-2.51/Encode.pm
-
Upload the interface_table_XXX archive to your server and uncompress it in a temporary directory (ex: /var/tmp/install/icinga/plugins/interfacetable-0.05)
-
Make the configure file executable:
# cd /var/tmp/install/icinga/plugins/interfacetable-0.05 # chmod a+x ./configure
Call ./configure with the wanted options.
[root@snoopy it_v3t-0.05-rc2]# ./configure [...]
Notes:
-
all options descriptions are available via ./configure --help
-
the software and perl library requirements are checked by ./configure:
[root@snoopy interfacetable_v3t-0.05-rc2]# ./configure [...] checking for perl... /usr/bin/perl checking for snmpget... /usr/bin/snmpget checking for snmpwalk... /usr/bin/snmpwalk checking for sudo... /usr/bin/sudo [...] checking for Sort::Naturally perl module... found checking for Exception::Class perl module... found checking for Time::HiRes perl module... found [...] -
without specifying any options, the plugin will be configured as following:
Global installation directories: -------------------------------- ${prefix}: /usr/local/interfacetable_v3t ${exec_prefix}: /usr/local/interfacetable_v3t libdir (for perl libraries): ${exec_prefix}/lib sysconfdir (for config file): ${prefix}/etc datarootdir (for html, css, js,...): ${prefix}/share Note: exec_prefix, libdir, sysconfdir and datadir can be changed for fine tuned installations Nagios & related options: ------------------------- Install user/group: nagios,nagios Nagios base dir: /usr/local/nagios Nagios libexec dir: /usr/local/nagios/libexec InterfaceTable_v3t addon CGI dir: /usr/local/interfacetable_v3t/sbin InterfaceTable_v3t addon CGI url: /interfacetable_v3t/cgi-bin InterfaceTable_v3t addon HTML url: /interfacetable_v3t Cache files dir: /tmp/.ifCache State files dir: /tmp/.ifState Graphing options: ----------------- Graphing solution name: pnp4nagios Graphing solution url: /pnp4nagios Apache & sudo options: ---------------------- Apache conf.d dir: /etc/httpd/conf.d Apache User: apache Apache AuthName: Nagios Access Sudoers file: /etc/sudoers Other options: ---------------------- Port performance data unit: bps MAX_PLUGIN_OUTPUT_LENGTH: 8192
Hereunder are the available option for ./configure:
| Keyword | Description | Default value |
|---|---|---|
| --help | Show the configure usage page | |
| --prefix="/path/to/interfacetable_v3t/dir" | Sets the directory where the software will be installed | /usr/local/interfacetable_v3t |
| --with-nagios-user="user" | Sets the owner of installed files | nagios |
| --with-nagios-group="grp" | Sets group of installed files | nagios |
| --with-nagios-base="/path/to/nagios/dir" | Sets the nagios base directory | /usr/local/nagios |
| --with-nagios-libexec="/path/to/nagios/dir" | Sets the nagios libexec directory, if not standard | /usr/local/nagios/libexec |
| --with-cachedir="/path/to/cache/dir" | Sets the directory where snmp responses are cached | /tmp/.ifCache |
| --with-statedir="/path/to/cache/dir" | Sets the directory where the interface states are stored | /tmp/.ifState |
| --with-htmldir="/path/to/html/dir" | Sets software HTML directory | /usr/local/interfacetable_v3t/share |
| --with-htmlurl="url" | Sets interface table URL location | http://myserver/interfacetable_v3t or /interfacetable_v3t |
| --with-cgidir="/path/to/cgi/dir" | Sets software cgi programs directory | /usr/local/interfacetable_v3t/sbin |
| --with-cgiurl="url" | Sets URL for interfacetable_v3t cgi programs | http://myserver/interfacetable_v3t/cgi-bin or /interfacetable_v3t/cgi-bin |
| --with-grapher="solution name" | Sets the graphing solution which will be in charge of processing the performance data. Possible values are pnp4nagios, nagiosgrapher, netwaysgrapherv2, ingraph | pnp4nagios |
| --with-grapher-url="grapher-url" | Sets URL to the graphing solution web interface | /pnp4nagios (some automated detection depending on the selected grapher solution) |
| --with-max-plugin-output-length= | Sets the maximum plugin output length as used during the nagios/icinga core compilation. If you used a non-default value, specify it here so the plugin would correctly detect the oversized plugin outputs. | 8192 |
| --with-portperfunit= | Sets the unit used to report traffic statistics. Could be reported in bits (counters) or in bps (calculated value, new and default since v0.05). Can be 'bit' or 'bps'. | bps |
| --with-httpd-conf="/path/to/conf/dir" | Sets path to Apache conf.d directory | Automated detection |
| --with-apache-user="user" | Sets path Apache runs with | Automated detection |
| --with-apache-authname="authname" | Sets value of AuthName directive in Apache config | Nagios Access (some automated detection for Icinga) |
| --with-sudoers="/path/to/sudoers" | Sets path to sudoers file | Automated detection |
- Configuration examples:
-
Nagios user
./configure --prefix=/usr/local/interfacetable_v3t --with-htmlurl=http://myserver/interfacetable_v3t -
Icinga user
./configure --prefix=/usr/local/interfacetable_v3t --with-nagios-user=icinga --with-nagios-group=icinga --with-nagios-base=/usr/local/icinga --with-htmlurl=http://myserver/interfacetable_v3t -
Changing cache and state files directory
./configure --prefix=/usr/local/interfacetable_v3t --with-nagios-user=icinga --with-nagios-group=icinga --with-nagios-base=/usr/local/icinga --with-cachedir=/usr/local/icinga/tmp/ifCache --with-statedir=/usr/local/icinga/tmp/ifState --with-htmlurl=http://myserver/interfacetable_v3tNote: by default, the html url for interfacetable_v3t is relative (/interfacetable_v3t). Even if this works well in most of the situations, it is recommended to change it to an absolute url including your server dns name or ip (http://myserver/interfacetable_v3t). Without that, in some cases the link returned in the plugin output will not be valid (for example in a notification email)
-
Generate and install the plugin files When the configuration fits your needs, call the make command as following:
make install
This copies everything to the right places in the file system: cgis and perl scripts, html/php files, css stylesheets and js files.
Then, you can call make to install an Apache configuration file to your web-server config directory
make install-apache-config
You can then update the sudoers file:
make install-sudo-config
This prepares the /etc/sudoers file so that the web server's account can call the cgi script (as shell script)
Note:
-
all the available make commands can be displayed by just entering make:
[root@server interfacetable_v3t-0.03b3]# make Please supply a command line argument (i.e. 'make all'). Available targets are: clean distclean install install-apache-config install-sudo-config fullinstall Usages: make install - This installs the plugin, cgi files, and html resources make install-apache-config - This installs the apache config file for interfacetable_v3t make install-sudo-config - This installs the sudo config for interfacetable_v3t make fullinstall - This installs the plugin, cgi files, html resources, and the apache config file for interfacetable_v3t -
all these make steps are combined in
make fullinstall -
after copying the configuration file for the web server you have to restart the web server (service httpd restart or /etc/init.d/apache2 restart).
Check that the plugin works Check that all the requirements are well installed by launching the script as the nagios/icinga user:
[icinga@snoopy libexec] ./check_interface_table_v3t.pl -V
./check_interface_table_v3t.pl (0.05)
This nagios plugin comes with ABSOLUTELY NO WARRANTY. You may redistribute
copies of this plugin under the terms of the GNU General Public License version 3 (GPLv3).
[icinga@snoopy libexec]
If not already the case, configure Nagios to display HTML links in plugin output
Edit cgi.cfg and set this option to zero
escape_html_tags=0
cgi.cfg is located in your configuration directory. (ex: /usr/local/nagios/etc)
If you use pnp4nagios as the graphing solution, you may be interested by the pnp4nagios templates provided with Interfacetable_v3t. To install them, copy the 3 files from the installation directory interface_table_v3t-x.xx/contrib/pnp4nagios to your pnp4nagios template directory (ex: /usr/local/pnp4nagios/share/templates)
The directory tree will be the following:
/usr/local/interfacetable_v3t
|-- etc (can contain some configuration files loaded by the --config option, optional)
|-- lib (perl libraries for the plugin)
|-- sbin (cgi scripts)
\`-- share
|-- css (css stylesheets)
|-- img (images)
|-- js (javascript functions)
\`-- tables (generated interface tables as html files)
Moreover, some files are installed automatically in some other locations:
- the perl plugin check_interface_table_v3t.pl is installed in the nagios plugin directory (/usr/local/nagios/libexec)
- the apache configuration file interfacetable_v3t.conf is installed in the apache configuration directory (/etc/apache2/conf.d)
The main part of the addon is the check_interface_table_v3t.pl perl script, which can be considered as the plugin itself. This script is indeed in charge of all the tasks of gathering node and interface info, thresholds comparison, change tracking and status/stats outputs.
Another interesting script is InterfaceTableReset_v3t.cgi. This CGI script gives you the possibility to reset the interface table of a node. Indeed, it is common that someone changes some ip addresses or some other properties. When tracked, these changes produce some alerts and you may want to update (=reset) the table to clean them. Resetting the table means to delete the corresponding state file (ex: in /tmp/.ifState).