[Monitoring] Cacti - Part 1 : Installation

Among opensource monitoring softwares, Cacti is a reference. This software is divided into 2 parts : a front office, i.e. a graphical user interface declined as a website but also a tool which works periodically to get datas from others servers / services.

Cacti 's goal is to collect numeric infromation about servers and services health and represent them as charts.
To work, cacti needs PHP, an application server as httpd by the Apache foundation, a databases server (MySQL) to store set-up and rrdtool to backup collected datas.

Cacti 's installation has several step but is quiet simple :

rrdtool installation
PHP installation and setting up
Cacti's installation
httpd setting up
Data collector installation

rrdtool installation :

There are 2 ways to install rrdtool via the package manager or by compiling it.
Here, we compile it because the version (1.2.11) provided by the package manager is bugged for data representation and we prefere the 1.2.29 version :

apt-get install libfreetype6-dev libart-2.0-dev
cd /usr/local/packages
wget http://oss.oetiker.ch/rrdtool/pub/rrdtool-1.2.29.tar.gz
tar zxf rrdtool-1.2.29.tar.gz
cd rrdtool-1.2.29
./configure --prefix=/usr/local/rrdtool-1.2.29 && make && make install
cd /usr/local/
ln -s rrdtool-1.2.29 rrdtool

PHP installation and setting up :

We work on the assumption that a httpd server and a MySQL server are already installedsont déjà installés (respectively into /usr/local/apache2 and /usr/local/mysql).
Now, we install PHP with some modules :

apt-get install zlib1g-dev perl libdbd-mysql-perl libnet-snmp-perl libxml2-dev libxml2 libcurl3 libcurl4-gnutls-dev gawk libpng12-dev libmcrypt-dev snmp
cd /usr/local/packages
wget http://fr3.php.net/get/php-5.2.8.tar.gz/from/fr.php.net/mirror
tar xzf php-5.2.8.tar.gz
cd php-5.2.8
./configure --prefix=/usr/local/php-5.2.8 --with-apxs2=/usr/local/apache2/bin/apxs --with-zlib --with-curl --enable-ftp --with-gd --with-mcrypt --with-mysql=/usr/local/mysql/ --with-snmp --enable-zip  --with-gnu-ld --enable-sockets
make
make install

Cacti's installation :

Cacti is a repository providing the website application but also data collector scripts.

cd /usr/local/packages
wget http://www.cacti.net/downloads/cacti-0.8.7e.tar.gz
tar xzf cacti-0.8.7e.tar.gz 
mv cacti-0.8.7e /usr/local/.
cd /usr/local/
ln -s cacti-0.8.7e cacti

Now, we have to set up the database creating a dedicated database and giving rights to a new MySQL user :

CREATE DATABASE cacti;
GRANT ALL PRIVILEGES ON cacti.* TO 'cacti'@'localhost' IDENTIFIED BY 'cacti';
FLUSH PRIVILEGES;

Creating the database's tables :

mysql -ucacti -pcacti cacti < /usr/local/cacti/cacti.sql

Then, the cacti's set up to connect to the databases server. Just edit the /usr/local/cacti/include/config.php file and adapt it depending the environment :

$database_type = "mysql";
$database_default = "cacti";
$database_hostname = "localhost";
$database_username = "cacti";
$database_password = "cacti";
$database_port = "3306";

httpd setting up :

The website set-up under httpd is easily made adding in the httpd.conf or httpd-vhost.conf file :

Alias /cacti "/usr/local/cacti"
<Directory "/usr/local/cacti">
    Options Indexes MultiViews FollowSymLinks
    AllowOverride None
    Order deny,allow
    Allow from all
    DirectoryIndex index.php
    AddType application/x-httpd-php .php
    php_flag magic_quotes_gpc Off
    php_flag short_open_tag On
    php_flag register_globals Off
    php_flag register_argc_argv On
    php_flag track_vars On
    # this setting is necessary for some locales
    php_value mbstring.func_overload 0
    php_value include_path .
    DirectoryIndex index.php
</Directory>

After an httpd restart (/usr/local/apache2/bin/apachectl restart) or a set-up reloading (/usr/local/apache2/bin/apachectl graceful), just connect to the cacti'sinterface (http://localhost/cacti).
When authenticating (by default with admin / admin), the interface asks to change password (recommended) then cacti is fully operational with a basic set-up for data collection.
Path to tools can be bad (for example rrdtool path if as here you have compiled it into a specific repository). To correct this, just indicate the right path to binaries.

Data collector installation :

Now, the visual cacti aspect is done, we have to install the data collector.
This program is very simple because it is a PHP script to install in the crontab (i.e. in the generic file /etc/crontab or in a user's crontab with the crontab -e command) :

*/5 *   * * *   /usr/local/php/bin/php /usr/local/cacti/poller.php >> /usr/local/cacti/log/poller.log

It's finished. Here, all 5 minutes, the data collector will be triggered all datas will be stored under the rrd format.

Pavnay