HowTo Install NRPE on Debian-Host

Hi,
Later in my last post - How To Install Nagios
I want to show you how to install NRPE plugin on your Debian-Hosts to monitoring from Nagios.

Install NRPE-Daemon and Nagios-Plugins on Debian-Linux Host.

1. Make sure you have a C compiler installed

# apt-get install make gcc g++

2. Install SSL for secure communication between Nagios-Server and Debian-Host

# apt-get install libssl-dev

3. Install SNMP (in case you like to query some SNMP via NRPE)

# apt-get install snmpd

# apt-get install snmp scli tkmib

4. Create Nagios user

# useradd -p nagios nagios

5. Install Nagios-Plugins

# cd /usr/src

# wget http://internode.dl.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.13.tar.gz

# tar -xzvf nagios-plugins-1.4.13.tar.gz

# cd nagios-plugins-1.4.13

# ./configure

# make

# make install

6. Fix permission for the Nagios director

# chown -R nagios:nagios /usr/local/nagios/

7. Install Xinetd

# apt-get install xinetd

8. Install and configure NRPE

# cd /usr/src

# wget http://waix.dl.sourceforge.net/sourceforge/nagios/nrpe-2.12.tar.gz

# tar -xzvf nrpe-2.12.tar.gz

# cd nrpe-2.12

# ./configure

# make all

# make install-plugin

# make install-daemon

# make install-daemon-config

# make install-xinetd

Edit /etc/xinetd.d/nrpe
# vi /etc/xinetd.d/nrpe
and add to only_from= your Nagios server IP

only_from = 127.0.0.1 192.168.1.101

Add the following entry for the NRPE daemon to the /etc/services file.

# echo "nrpe 5666/tcp #NRPE" >> /etc/services

Restart the NRPE service

# /etc/init.d/xinetd restart

Test if NRPE is listening:

# netstat -l | grep nrpe

The output out this command should show something like this:

tcp 0 0 *:nrpe *:* LISTEN

Next, check to make sure the NRPE daemon is functioning properly. To do this, run the check_nrpe plugin that was installed for testing purposes.

# /usr/local/nagios/libexec/check_nrpe -H localhost

If everything is fine you will see this output:

NRPE v2.12

9. Test the NRPE from the Nagios-Server
Now we want to test if we can query some information from the Debian-Host via NRPE from the Nagios-Server.
So switch into /usr/local/nagios/libexec on your Nagios Server and check if you have the check_nrpe plugin.

# ls - l check_ nrpe

In case you dont have the check_nrpe plugin you need to download and compile NRPE. (See Step 8)
run the next command:

# ./check_nrpe -H HostIPAddress -c check_users

You should get something like this back:

USERS OK - 1 users currently logged in |users=1;5;10;0

Great! Your Nagios server is able to communicate with the Debian-Host.

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How To Install Nagios on Ubuntu

Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes.

Download, install and Configure Apache
first we have to install some necessary compliers and Apache to run Nagios.
run the next commands:

# sudo apt-get install build-essential

# sudo apt-get install libgd2-xpm-dev

# sudo apt-get install apache2

# sudo apt-get install php5-common php5 libapache2-mod-php5

Configure Apache to use PHP:

Run in a terminal:

# sudo vi /etc/apache2/apache2.conf

Paste the following into the file:

DirectoryIndex index.html index.php index.cgi

and restart the server with the command

# sudo /etc/init.d/apache2 restart

Download, install, and configure Nagios
Create a user to run the service and a group to run external commands:

# sudo useradd -m nagios

# sudo passwd nagios

# sudo groupadd nagcmd

# sudo usermod -a -G nagcmd nagios

# sudo usermod -a -G nagcmd www-data

Download the current version of Nagios and Nagios Plugins from - http://www.nagios.org/download/

Extract the Nagios tar:

# sudo tar -zxvf nagios-3.1.2.tar.gz

and change to the nagios-3.1.2 directory

# cd  nagios-3.1.2

Now install the Nagios use the flowing commands :

# sudo ./configure --with-command-group=nagcmd

# sudo make all

# sudo make install

# sudo make install-init

# sudo make install-config

# sudo make install-commandmode

# sudo make install-webconf

Add a user for the Nagios interface:

# sudo htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Extract and compile the Nagios-plugins:

# tar -zxvf nagios-plugins-1.4.14.tar.gz

# cd nagios-plugins-1.4.14

# sudo ./configure --with-nagios-user=nagios --with-nagios-group=nagios

# sudo make

# sudo make install

Create a link to start the service:

# sudo ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios

Verify the config:

# sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Start Nagios:

# sudo /etc/init.d/nagios start

You should now be able to log into the Nagios web interface (http://localhost/nagios) using the nagiosadmin user and password.

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How To, MySQL to CSV - Script

Hi
I wanted to share a new script that I was writing,
This script knows how to take SQL queries, convert them to csv files and send them by eMail.

the script is divided to 2 files:
the first one contain all the sql queries, and the second do all the amazing job.

The fist file called SQL.reports can be download from HERE, contain the sql queries, the syntax must be like the example:

ReportName your_report_name
sql your query

ReportName your_second_report_name
sql select * from tableA where [...]

The script file called MySQL_to_csv.sh can be download from HERE,
the only things you need to do for this to work is to fill the next parameters in the script:

DBhost="localhost"
DBname="your DB name"
DBuser="your DB user name"
DBpass="your DB password"
Mail_to='list of mail with space between them'

please do not touch the rest of the script.

After you have been download those 2 file, placed them in the same directory on your server lets say /opt/reports
and make sure you give them a permission

# chmod +x /opt/reports/*

now all left to do is to run the MySQL_to_csv.sh script
# /opt/reports/MySQL_to_csv.sh
and check you mailBox.
you can also add the script to corntab to run in your own scheduling

Enjoy.
And please comment (-;

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How To sort and find duplicate records

Hi,
I'm was asked to sort a password file, to show all duplicate users and their UIDs.
For Example if you have a file like this:

UID    UserName   Password
----   --------   ----------
1236   john       oe93kf9034j
936    max        fkl03kf032j
9381   keren      fg38uf6124t
8988   john       fj3589gjf01
9834   roma       fgj390jf203
8915   max        gf23j09g305
341    john       mf9244t24t4
9841   david      f02jflp3053
43745  david      23hkfg03g35
4956   ron        04fk054f2e4
69595  max        kvf9035g022
7765   john       mg30gk30gkw

I want to show all the duplicate users and all their UIDs like this:

john - 1236 8988 341 7765
max - 936 8915 69595
david - 9841 43745

Solution
To find all duplicate users we'll use the next script:
$ cut -f2 yourFile | sort | uniq -d
it'll display:

john
max
david

Now we want to know all the UIDs of those users
create a new file with vi
$ vi dup_users.sh
and copy the folloing lines:

dup=`cut -f2 yourFile | sort | uniq -d`

for a in $dup
do
        echo $a - `cat yourFlie | grep $a | cut -f1`
done

It will search for each user all UIDs he has and display them like the example on the top.

More
$ sort yourFlie | uniq -u # only the unique, non-repeated lines
$ sort yourFile | uniq -d # repeated lines
$ sort yourFile | uniq -c # all lines + count repeated lines

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linux/kernel/panic.c Wallpaper

A New Wallpaper I found    

  Discover Simple, Private Sharing at Drop.io 

   

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How To change user name and UID

Hi,
I was asked to change the ID of the mysql user and gourp on one of my servers.
this is a very simple to do.

first type
# id mysql

uid=101(mysql) gid=103(mysql) groups=103(mysql) 

to change the user id type:
# usermod -u 25 mysql
to change the group id run the next command under root user:

# vigr

search the mysql group mysql:x:103: the change it to 25 mysql:x:25:
(save with /wq like regular vi)
OR
# groupmod -g 25 mysql
now run again:
# id mysql

uid=25(mysql) gid=25(mysql) groups=25(mysql)

to change user name run:
# usermod -l old_name new_name
to change home directory run:
# usermod -d /home/user_name user_name
to change group name run:
# groupmod -n old_name new_name

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How to configure MySQL Cluster with Heartbeat

In this post we'll discuss how to set up a MySQL cluster with two serves, storage and Heartbeat.
I'm using CentOS 5 distribution on both machines, MySQL 5.1 and a mounted directory on both servers to /var/lib/mysql

Pre-Configuration
You need to install MySQL on both machines.
Assign hostname dbserver01, dbserver02.
dbserver01 is the primary node with IP address 192.168.1.101 to eth0.
and dbserver02 is the slave one with ip address 192.168.1.102.
192.168.1.103 is the virtual IP that will be used for MySQL.

Configuration (do those steps on both servers)
install the Heartbeat package:
# yum install heartbeat

copy the next configuration files to the /etc/ha.d directory:
# cp /usr/share/doc/heartbeat-version/authkeys /etc/ha.d
# cp /usr/share/doc/heartbeat-version/ha.cf /etc/ha.d
# cp /usr/share/doc/heartbeat-version/haresources /etc/ha.d

First we will edit the authkeys file,
# vi /etc/ha.d/authkeys
copy from here:

auth 2
2 sha1 test-HA

change the permission of the authkeys file:
# chmod 600 /etc/ha.d/authkeys

Now let's edit the most important file (ha.cf)
# vi /etc/ha.d/ha/cf
add the following lines into the file:

logfile /var/log/ha-log
logfacility local0
keepalive 2
deadtime 30
initdead 120
bcast eth0
udpport 694
auto_failback on
node dbserver01
node dbserver02 

The last file we need to edit is haresources:
# vi /etc/ha.d/haresources
add the following line:

dbserver01 192.168.1.103 netfs mysqld 

Now all we need to do is to start the hearbeat service on both machines:
# /etc/init.d/heartbeat start
the virtual IP address 192.168.1.103 is now on dbserver01 and MySQL is up and running.
if dbserver01 will crashed from any reason the IP address will jump to dbserver02 the the MySQL service will start automatic.

Enjoy.
And please comment (-;

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