Archive for the ‘Nagios Tutorial’ Category
NagiosQL is a web front end for simplifying the set up of the configuration files for Nagios. In this guide I will only be installing NagiosQL. If you also need to install Nagios, an excellent guide to use for installing from source can be found at http://nagios.sourceforge.net/docs/3_0/quickstart-fedora.html. Generally I prefer to install using an RPM package from a Yum repository, but I have not yet found a repository that contains the Nagios 3 package for CentOS/Red Hat.
First install the MySQL and PHP packages needed to support NagiosQL. I am reinstalling, so hopefully the packages I’ve listed will pick up everything that is required:
shell# yum install mysql php php-mysql php-pear
Now install the HTML_Template_IT Pear module:
shell# pear install HTML_Template_IT
Download the NagiosQL archive from http://sourceforge.net/projects/nagiosql/, then extract the program files:
shell# tar zxvf nagiosql303.tar.gz
Rename the extracted directory for simplicity:
shell# mv nagiosql3 nagiosql
Now move the directory to the webroot
shell# mv nagiosql /var/www/html/
We need to set up new directories to hold the configuration files generated by NagiosQL:
shell# mkdir /etc/nagiosql
shell# mkdir /etc/nagiosql/hosts
shell# mkdir /etc/nagiosql/services
shell# mkdir /etc/nagiosql/backup
shell# mkdir /etc/nagiosql/backup/hosts
shell# mkdir /etc/nagiosql/backup/services
Next we’ll modify the main Nagios configuration file /usr/local/nagios/etc/nagios.cfg and add the following lines to tell Nagios where to look for our new configurations files generated by NagiosQL. Before proceeding you may want to comment out the existing cfg_file and cfg_dir entries in the object configuration section of this file to simplify things and exclusively use the configuration files generated by NagiosQL.
Adding these lines to /usr/local/nagios/etc/nagios.cfg is required:
Optionally specify these lines as well:
Now let’s modify the permissions on several files and directories to ensure that Nagios will work correctly with our new configuration file structure.
Nagios main configuration files:
shell# ln -s /usr/local/nagios /etc/nagios
shell# chgrp nagios /etc/nagios
shell# chgrp nagios /etc/nagios/nagios.cfg
shell# chgrp nagios /etc/nagios/cgi.cfg
shell# chmod 775 /etc/nagios
shell# chmod 664 /etc/nagios/nagios.cfg
shell# chmod 664 /etc/nagios/cgi.cfg
NagiosQL generated configuration files:
shell# chmod 6755 /etc/nagiosql
shell# chown apache.nagios /etc/nagiosql
shell# chmod 6755 /etc/nagiosql/hosts
shell# chown apache.nagios /etc/nagiosql/hosts
shell# chmod 6755 /etc/nagiosql/services
shell# chown apache.nagios /etc/nagiosql/services
shell# chmod 6755 /etc/nagiosql/backup
shell# chown apache.nagios /etc/nagiosql/backup
shell# chmod 6755 /etc/nagiosql/backup/hosts
shell# chown apache.nagios /etc/nagiosql/backup/hosts
shell# chmod 6755 /etc/nagiosql/backup/services
shell# chown apache.nagios /etc/nagiosql/backup/services
Let’s ensure that the Nagios is executable by the Apache group:
shell# chown nagios.apache /usr/local/nagios/bin/nagios
shell# chmod 750 /usr/local/nagios/bin/nagios
Run the preflight check to verify that there are no errors in the nagios.cfg file (will not work until configuration files are created from NagiosQL):
shell# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
We need to create a file in the NagiosQL install directory to allow us to proceed to the web based portion of the install:
shell# touch /var/www/html/nagiosql/install/ENABLE_INSTALLER
Also the Apache user needs write permissions to the nagiosql/config directory to write a settings file:
shell# chown apache /var/www/html/nagiosql/config
Now we point our browser to http://OurServer/nagiosql and are presented with this screen:
The installer will verify our environment and make sure everything is in order:
Now we need to enter our configuration information for server, database, users, and passwords:
We will now be informed that we need to delete the nagiosql/install directory to finish the installation, so back on the console:
shell# rm -rf /var/www/html/nagiosql/install
Log in to the web application by entering the admin password you specified earlier:
Now we’ll import the nagios commands configuration file, click Tools on the left:
Click Data Import under Tools:
In the Import file text box, highlight /etc/nagios/objects/commands.cfg and click Import.
At the bottom of the page it should display that records were successfully inserted. In the Import file text box, highlight /etc/nagios/objects/timeperiods.cfg and click Import.
I have generally had the best success importing only these two configuration files and then manually adding my hosts and services in NagiosQL. Good luck monitoring!
Nguồn: tác giả david, thegioigiaiphap.vn
@6/2011 – cuongk6t – Nguyen Quoc Cuong
This guide is intended to provide you with simple instructions on how to install Nagios from source (code) on Fedora and have it monitoring your local machine inside of 20 minutes. No advanced installation options are discussed here – just the basics that will work for 95% of users who want to get started.
These instructions were written based on a standard Fedora Core 6 Linux distribution.
What You’ll End Up With
If you follow these instructions, here’s what you’ll end up with:
- Nagios and the plugins will be installed underneath /usr/local/nagios
- Nagios will be configured to monitor a few aspects of your local system (CPU load, disk usage, etc.)
- The Nagios web interface will be accessible at http://localhost/nagios/
During portions of the installation you’ll need to have root access to your machine.
Make sure you’ve installed the following packages on your Fedora installation before continuing.
- GCC compiler
- GD development libraries
You can use yum to install these packages by running the following commands (as root):
yum install httpd php yum install gcc glibc glibc-common yum install gd gd-devel
1) Create Account Information
Become the root user.
Create a new nagios user account and give it a password.
/usr/sbin/useradd -m nagios passwd nagios
Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.
/usr/sbin/groupadd nagcmd /usr/sbin/usermod -a -G nagcmd nagios /usr/sbin/usermod -a -G nagcmd apache
2) Download Nagios and the Plugins
Create a directory for storing the downloads.
mkdir ~/downloads cd ~/downloads
Download the source code tarballs of both Nagios and the Nagios plugins (visit http://www.nagios.org/download/ for links to the latest versions). These directions were tested with Nagios 3.1.1 and Nagios Plugins 1.4.11.
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.3.tar.gz wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz
3) Compile and Install Nagios
Extract the Nagios source code tarball.
cd ~/downloads tar xzf nagios-3.2.3.tar.gz cd nagios-3.2.3
Run the Nagios configure script, passing the name of the group you created earlier like so:
Compile the Nagios source code.
Install binaries, init script, sample config files and set permissions on the external command directory.
make install make install-init make install-config make install-commandmode
Don’t start Nagios yet – there’s still more that needs to be done…
4) Customize Configuration
Sample configuration files have now been installed in the /usr/local/nagios/etc directory. These sample files should work fine for getting started with Nagios. You’ll need to make just one change before you proceed…
Edit the /usr/local/nagios/etc/objects/contacts.cfg config file with your favorite editor and change the email address associated with the nagiosadmin contact definition to the address you’d like to use for receiving alerts.
5) Configure the Web Interface
Install the Nagios web config file in the Apache conf.d directory.
Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account – you’ll need it later.
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Restart Apache to make the new settings take effect.
service httpd restart
Note: Consider implementing the ehanced CGI security measures described here to ensure that your web authentication credentials are not compromised.
6) Compile and Install the Nagios Plugins
Extract the Nagios plugins source code tarball.
cd ~/downloads tar xzf nagios-plugins-1.4.11.tar.gz cd nagios-plugins-1.4.11
Compile and install the plugins.
./configure --with-nagios-user=nagios --with-nagios-group=nagios make make install
7) Start Nagios
Add Nagios to the list of system services and have it automatically start when the system boots.
chkconfig --add nagios chkconfig nagios on
Verify the sample Nagios configuration files.
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
If there are no errors, start Nagios.
service nagios start
8) Modify SELinux Settings
Fedora ships with SELinux (Security Enhanced Linux) installed and in Enforcing mode by default. This can result in “Internal Server Error” messages when you attempt to access the Nagios CGIs.
See if SELinux is in Enforcing mode.
Put SELinux into Permissive mode.
To make this change permanent, you’ll have to modify the settings in /etc/selinux/config and reboot.
Instead of disabling SELinux or setting it to permissive mode, you can use the following command to run the CGIs under SELinux enforcing/targeted mode:
chcon -R -t httpd_sys_content_t /usr/local/nagios/sbin/ chcon -R -t httpd_sys_content_t /usr/local/nagios/share/
9) Login to the Web Interface
You should now be able to access the Nagios web interface at the URL below. You’ll be prompted for the username (nagiosadmin) and password you specified earlier.
Click on the “Service Detail” navbar link to see details of what’s being monitored on your local machine. It will take a few minutes for Nagios to check all the services associated with your machine, as the checks are spread out over time.
10) Other Modifications
Make sure your machine’s firewall rules are configured to allow access to the web server if you want to access the Nagios interface remotely.
Configuring email notifications is out of the scope of this documentation. While Nagios is currently configured to send you email notifications, your system may not yet have a mail program properly installed or configured. Refer to your system documentation, search the web, or look to the Nagios Support Portal or Nagios Community Wiki for specific instructions on configuring your system to send email messages to external addresses. More information on notifications can be found here.
11) You’re Done
Congratulations! You sucessfully installed Nagios. Your journey into monitoring is just beginning. You’ll no doubt want to monitor more than just your local machine, so check out the following docs…
- Monitoring Windows machines
- Monitoring Linux/Unix machines
- Monitoring Netware servers
- Monitoring routers/switches
- Monitoring publicly available services (HTTP, FTP, SSH, etc.)
6/2011 – cuongk6t