Probando Nagios

Monitoreando con Nagios

EN LA MÁQUINA A MONITOREAR instalar nagios-plugins y también el paquete openssl-devel

yum install openssl-devel

Para instalar el plugin de Nagios seguir estos pasos:

Instalar el Plugin de Nagios desde su página oficial (se supone descargado el paquete dentro de la

carpeta downloads).

[hostremoto]# cd /home/downloads

[hostremoto]# tar xvfz nagios-plugins-1.4.11.tar.gz

[hostremoto]# cd nagios-plugins-1.4.11

[hostremoto]# export LDFLAGS=-ldl

[hostremoto]# ./configure –with-nagios-user=nagios –with-nagios-group=nagios –enable-redhat-pthread-

workaround

[hostremoto]# make

[hostremoto]# make install

[hostremoto]# chown nagios:nagios /usr/local/nagios

[hostremoto]# chown -R nagios:nagios /usr/local/nagios/libexec/

Fuente: http://www.nagios-do.org/?p=192

Ahora instalar el paquete nrpe disponible en la página de nagios, descomprimirlo, ir dentro del

directorio y ejecutar

Nota: NRPE (Nagios Remote Plugin Executor) permite monitorizar dispositivos de redremotos usando

Nagios.

[root@localhost nrpe-2.13]# ./configure

Lo anterior da como salida:

[root@localhost nrpe-2.13]# yum search openssl-devel

Loaded plugins: fastestmirror, refresh-packagekit, security

Loading mirror speeds from cached hostfile

* base: centosc6.centos.org

* extras: centosq3.centos.org

* updates: centosr3.centos.org

========================== N/S Matched: openssl-devel ==========================

openssl-devel.i686 : Files for development of applications which will use

: OpenSSL

Name and summary matches only, use "search all" for everything.

[root@localhost nrpe-2.13]# yum install openssl-devel

Loaded plugins: fastestmirror, refresh-packagekit, security

Loading mirror speeds from cached hostfile

* base: centosz3.centos.org

* extras: centosx5.centos.org

* updates: centosp4.centos.org

Setting up Install Process

Resolving Dependencies

--> Running transaction check

---> Package openssl-devel.i686 0:1.0.0-25.el6_3.1 will be installed

--> Processing Dependency: openssl = 1.0.0-25.el6_3.1 for package: openssl-devel-1.0.0-25.el6_3.1.i686

--> Processing Dependency: krb5-devel for package: openssl-devel-1.0.0-25.el6_3.1.i686


---> Package krb5-devel.i686 0:1.9-33.el6_3.3 will be installed

--> Processing Dependency: krb5-libs = 1.9-33.el6_3.3 for package: krb5-devel-1.9-33.el6_3.3.i686

--> Processing Dependency: libselinux-devel for package: krb5-devel-1.9-33.el6_3.3.i686

--> Processing Dependency: libcom_err-devel for package: krb5-devel-1.9-33.el6_3.3.i686

--> Processing Dependency: keyutils-libs-devel for package: krb5-devel-1.9-33.el6_3.3.i686

---> Package openssl.i686 0:1.0.0-20.el6 will be updated

---> Package openssl.i686 0:1.0.0-25.el6_3.1 will be an update


---> Package keyutils-libs-devel.i686 0:1.4-4.el6 will be installed

--> Processing Dependency: keyutils-libs = 1.4-4.el6 for package: keyutils-libs-devel-1.4-4.el6.i686

---> Package krb5-libs.i686 0:1.9-22.el6 will be updated

--> Processing Dependency: krb5-libs = 1.9-22.el6 for package: krb5-workstation-1.9-22.el6.i686

---> Package krb5-libs.i686 0:1.9-33.el6_3.3 will be an update

---> Package libcom_err-devel.i686 0:1.41.12-12.el6 will be installed

--> Processing Dependency: libcom_err = 1.41.12-12.el6 for package: libcom_err-devel-1.41.12-

12.el6.i686

---> Package libselinux-devel.i686 0:2.0.94-5.3.el6 will be installed

--> Processing Dependency: libselinux = 2.0.94-5.3.el6 for package: libselinux-devel-2.0.94-

5.3.el6.i686

--> Processing Dependency: libsepol-devel >= 2.0.32-1 for package: libselinux-devel-2.0.94-5.3.el6.i686

--> Processing Dependency: pkgconfig(libsepol) for package: libselinux-devel-2.0.94-5.3.el6.i686


---> Package keyutils-libs.i686 0:1.4-3.el6 will be updated

--> Processing Dependency: keyutils-libs = 1.4-3.el6 for package: keyutils-1.4-3.el6.i686

---> Package keyutils-libs.i686 0:1.4-4.el6 will be an update

---> Package krb5-workstation.i686 0:1.9-22.el6 will be updated

---> Package krb5-workstation.i686 0:1.9-33.el6_3.3 will be an update

---> Package libcom_err.i686 0:1.41.12-11.el6 will be updated

--> Processing Dependency: libcom_err = 1.41.12-11.el6 for package: libss-1.41.12-11.el6.i686

--> Processing Dependency: libcom_err = 1.41.12-11.el6 for package: e2fsprogs-libs-1.41.12-11.el6.i686

--> Processing Dependency: libcom_err = 1.41.12-11.el6 for package: e2fsprogs-1.41.12-11.el6.i686

---> Package libcom_err.i686 0:1.41.12-12.el6 will be an update

---> Package libselinux.i686 0:2.0.94-5.2.el6 will be updated

--> Processing Dependency: libselinux = 2.0.94-5.2.el6 for package: libselinux-utils-2.0.94-

5.2.el6.i686

--> Processing Dependency: libselinux = 2.0.94-5.2.el6 for package: libselinux-python-2.0.94-

5.2.el6.i686

---> Package libselinux.i686 0:2.0.94-5.3.el6 will be an update

---> Package libsepol-devel.i686 0:2.0.41-4.el6 will be installed


---> Package e2fsprogs.i686 0:1.41.12-11.el6 will be updated

---> Package e2fsprogs.i686 0:1.41.12-12.el6 will be an update

---> Package e2fsprogs-libs.i686 0:1.41.12-11.el6 will be updated

---> Package e2fsprogs-libs.i686 0:1.41.12-12.el6 will be an update

---> Package keyutils.i686 0:1.4-3.el6 will be updated

---> Package keyutils.i686 0:1.4-4.el6 will be an update

---> Package libselinux-python.i686 0:2.0.94-5.2.el6 will be updated

---> Package libselinux-python.i686 0:2.0.94-5.3.el6 will be an update

---> Package libselinux-utils.i686 0:2.0.94-5.2.el6 will be updated

---> Package libselinux-utils.i686 0:2.0.94-5.3.el6 will be an update

---> Package libss.i686 0:1.41.12-11.el6 will be updated

---> Package libss.i686 0:1.41.12-12.el6 will be an update

--> Finished Dependency Resolution

Dependencies Resolved

================================================================================

Package Arch Version Repository Size

================================================================================

Installing:

openssl-devel i686 1.0.0-25.el6_3.1 updates 1.1 M

Installing for dependencies:

keyutils-libs-devel i686 1.4-4.el6 base 28 k

krb5-devel i686 1.9-33.el6_3.3 updates 1.2 M

libcom_err-devel i686 1.41.12-12.el6 base 31 k

libselinux-devel i686 2.0.94-5.3.el6 base 136 k

libsepol-devel i686 2.0.41-4.el6 base 64 k

Updating for dependencies:

e2fsprogs i686 1.41.12-12.el6 base 551 k

e2fsprogs-libs i686 1.41.12-12.el6 base 126 k

keyutils i686 1.4-4.el6 base 38 k

keyutils-libs i686 1.4-4.el6 base 20 k

krb5-libs i686 1.9-33.el6_3.3 updates 720 k

krb5-workstation i686 1.9-33.el6_3.3 updates 412 k

libcom_err i686 1.41.12-12.el6 base 36 k

libselinux i686 2.0.94-5.3.el6 base 108 k

libselinux-python i686 2.0.94-5.3.el6 base 199 k

libselinux-utils i686 2.0.94-5.3.el6 base 81 k

libss i686 1.41.12-12.el6 base 40 k

openssl i686 1.0.0-25.el6_3.1 updates 1.4 M

Transaction Summary

================================================================================

Install 6 Package(s)

Upgrade 12 Package(s)

Total download size: 6.2 M

Is this ok [y/N]: y

Downloading Packages:

(1/18): e2fsprogs-1.41.12-12.el6.i686.rpm | 551 kB 00:04

(2/18): e2fsprogs-libs-1.41.12-12.el6.i686.rpm | 126 kB 00:01

(3/18): keyutils-1.4-4.el6.i686.rpm | 38 kB 00:00

(4/18): keyutils-libs-1.4-4.el6.i686.rpm | 20 kB 00:00

(5/18): keyutils-libs-devel-1.4-4.el6.i686.rpm | 28 kB 00:00

http://centosp4.centos.org/centos/6.3/updates/i386/Packages/krb5-devel-1.9-33.el6_3.3.i686.rpm: [Errno

12] Timeout on http://centosp4.centos.org/centos/6.3/updates/i386/Packages/krb5-devel-1.9-

33.el6_3.3.i686.rpm: (28, 'Operation too slow. Less than 1 bytes/sec transfered the last 30 seconds')

Trying other mirror.

(6/18): krb5-devel-1.9-33.el6_3.3.i686.rpm | 1.2 MB 00:08

(7/18): krb5-libs-1.9-33.el6_3.3.i686.rpm | 720 kB 00:06

(8/18): krb5-workstation-1.9-33.el6_3.3.i686.rpm | 412 kB 00:03

(9/18): libcom_err-1.41.12-12.el6.i686.rpm | 36 kB 00:00

(10/18): libcom_err-devel-1.41.12-12.el6.i686.rpm | 31 kB 00:00

(11/18): libselinux-2.0.94-5.3.el6.i686.rpm | 108 kB 00:01

(12/18): libselinux-devel-2.0.94-5.3.el6.i686.rpm | 136 kB 00:01

(13/18): libselinux-python-2.0.94-5.3.el6.i686.rpm | 199 kB 00:01

(14/18): libselinux-utils-2.0.94-5.3.el6.i686.rpm | 81 kB 00:00

(15/18): libsepol-devel-2.0.41-4.el6.i686.rpm | 64 kB 00:00

(16/18): libss-1.41.12-12.el6.i686.rpm | 40 kB 00:00

(17/18): openssl-1.0.0-25.el6_3.1.i686.rpm | 1.4 MB 00:11

(18/18): openssl-devel-1.0.0-25.el6_3.1.i686.rpm | 1.1 MB 00:09

--------------------------------------------------------------------------------

Total 66 kB/s | 6.2 MB 01:36

Running rpm_check_debug

Running Transaction Test

Transaction Test Succeeded

Running Transaction

Warning: RPMDB altered outside of yum.

Installing : libsepol-devel-2.0.41-4.el6.i686 1/30

Updating : libcom_err-1.41.12-12.el6.i686 2/30

Updating : libselinux-2.0.94-5.3.el6.i686 3/30

Updating : keyutils-libs-1.4-4.el6.i686 4/30

Updating : krb5-libs-1.9-33.el6_3.3.i686 5/30

Updating : libss-1.41.12-12.el6.i686 6/30

Installing : keyutils-libs-devel-1.4-4.el6.i686 7/30

Installing : libselinux-devel-2.0.94-5.3.el6.i686 8/30

Installing : libcom_err-devel-1.41.12-12.el6.i686 9/30

Installing : krb5-devel-1.9-33.el6_3.3.i686 10/30

Updating : openssl-1.0.0-25.el6_3.1.i686 11/30

Updating : e2fsprogs-libs-1.41.12-12.el6.i686 12/30

Installing : openssl-devel-1.0.0-25.el6_3.1.i686 13/30

Updating : e2fsprogs-1.41.12-12.el6.i686 14/30

Updating : krb5-workstation-1.9-33.el6_3.3.i686 15/30

Updating : keyutils-1.4-4.el6.i686 16/30

Updating : libselinux-utils-2.0.94-5.3.el6.i686 17/30

Updating : libselinux-python-2.0.94-5.3.el6.i686 18/30

Cleanup : krb5-workstation-1.9-22.el6.i686 19/30

Cleanup : e2fsprogs-1.41.12-11.el6.i686 20/30

Cleanup : openssl-1.0.0-20.el6.i686 21/30

Cleanup : krb5-libs-1.9-22.el6.i686 22/30

Cleanup : e2fsprogs-libs-1.41.12-11.el6.i686 23/30

Cleanup : libss-1.41.12-11.el6.i686 24/30

Cleanup : keyutils-1.4-3.el6.i686 25/30

Cleanup : libselinux-python-2.0.94-5.2.el6.i686 26/30

Cleanup : libselinux-utils-2.0.94-5.2.el6.i686 27/30

Cleanup : libselinux-2.0.94-5.2.el6.i686 28/30

Cleanup : keyutils-libs-1.4-3.el6.i686 29/30

Cleanup : libcom_err-1.41.12-11.el6.i686 30/30

Installed:

openssl-devel.i686 0:1.0.0-25.el6_3.1

Dependency Installed:

keyutils-libs-devel.i686 0:1.4-4.el6 krb5-devel.i686 0:1.9-33.el6_3.3

libcom_err-devel.i686 0:1.41.12-12.el6 libselinux-devel.i686 0:2.0.94-5.3.el6

libsepol-devel.i686 0:2.0.41-4.el6

Dependency Updated:

e2fsprogs.i686 0:1.41.12-12.el6

e2fsprogs-libs.i686 0:1.41.12-12.el6

keyutils.i686 0:1.4-4.el6

keyutils-libs.i686 0:1.4-4.el6

krb5-libs.i686 0:1.9-33.el6_3.3

krb5-workstation.i686 0:1.9-33.el6_3.3

libcom_err.i686 0:1.41.12-12.el6

libselinux.i686 0:2.0.94-5.3.el6

libselinux-python.i686 0:2.0.94-5.3.el6

libselinux-utils.i686 0:2.0.94-5.3.el6

libss.i686 0:1.41.12-12.el6

openssl.i686 0:1.0.0-25.el6_3.1

Complete!

[root@localhost nrpe-2.13]# ./configure

checking for a BSD-compatible install... /usr/bin/install -c

checking build system type... i686-pc-linux-gnu

checking host system type... i686-pc-linux-gnu

checking for gcc... gcc

checking for C compiler default output file name... a.out

checking whether the C compiler works... yes

checking whether we are cross compiling... no

checking for suffix of executables...

checking for suffix of object files... o

checking whether we are using the GNU C compiler... yes

checking whether gcc accepts -g... yes

checking for gcc option to accept ANSI C... none needed

checking whether make sets $(MAKE)... yes

checking how to run the C preprocessor... gcc -E

checking for egrep... grep -E

checking for ANSI C header files... yes

checking whether time.h and sys/time.h may both be included... yes

checking for sys/wait.h that is POSIX.1 compatible... yes

checking for sys/types.h... yes

checking for sys/stat.h... yes

checking for stdlib.h... yes

checking for string.h... yes

checking for memory.h... yes

checking for strings.h... yes

checking for inttypes.h... yes

checking for stdint.h... yes

checking for unistd.h... yes

checking ctype.h usability... yes

checking ctype.h presence... yes

checking for ctype.h... yes

checking dirent.h usability... yes

checking dirent.h presence... yes

checking for dirent.h... yes

checking errno.h usability... yes

checking errno.h presence... yes

checking for errno.h... yes

checking fcntl.h usability... yes

checking fcntl.h presence... yes

checking for fcntl.h... yes

checking getopt.h usability... yes

checking getopt.h presence... yes

checking for getopt.h... yes

checking grp.h usability... yes

checking grp.h presence... yes

checking for grp.h... yes

checking for inttypes.h... (cached) yes

checking netdb.h usability... yes

checking netdb.h presence... yes

checking for netdb.h... yes

checking pwd.h usability... yes

checking pwd.h presence... yes

checking for pwd.h... yes

checking signal.h usability... yes

checking signal.h presence... yes

checking for signal.h... yes

checking for stdint.h... (cached) yes

checking for strings.h... (cached) yes

checking for string.h... (cached) yes

checking syslog.h usability... yes

checking syslog.h presence... yes

checking for syslog.h... yes

checking tcpd.h usability... no

checking tcpd.h presence... no

checking for tcpd.h... no

checking for unistd.h... (cached) yes

checking arpa/inet.h usability... yes

checking arpa/inet.h presence... yes

checking for arpa/inet.h... yes

checking netinet/in.h usability... yes

checking netinet/in.h presence... yes

checking for netinet/in.h... yes

checking socket.h usability... no

checking socket.h presence... no

checking for socket.h... no

checking for sys/types.h... (cached) yes

checking sys/time.h usability... yes

checking sys/time.h presence... yes

checking for sys/time.h... yes

checking sys/resource.h usability... yes

checking sys/resource.h presence... yes

checking for sys/resource.h... yes

checking for sys/wait.h... (cached) yes

checking sys/socket.h usability... yes

checking sys/socket.h presence... yes

checking for sys/socket.h... yes

checking for sys/stat.h... (cached) yes

checking for an ANSI C-conforming const... yes

checking whether struct tm is in sys/time.h or time.h... time.h

checking for mode_t... yes

checking for pid_t... yes

checking for size_t... yes

checking return type of signal handlers... void

checking for uid_t in sys/types.h... yes

checking type of array argument to getgroups... gid_t

checking for int... yes

checking size of int... 4

checking for short... yes

checking size of short... 2

checking for long... yes

checking size of long... 4

checking for uint32_t... yes

checking for u_int32_t... yes

checking for int32_t... yes

checking for va_copy... yes

checking for vsnprintf... yes

checking for snprintf... yes

checking for asprintf... yes

checking for vasprintf... yes

checking for C99 vsnprintf... yes

checking for getopt_long... yes

checking for main in -lnsl... yes

checking for socket in -lsocket... no

checking for main in -lwrap... no

checking for strdup... yes

checking for strstr... yes

checking for strtoul... yes

checking for initgroups... yes

checking for closesocket... no

checking for socklen_t... yes

checking for type of socket size... size_t

checking for SSL headers... SSL headers found in /usr

checking for SSL libraries... SSL libraries found in /usr/lib

*** Generating DH Parameters for SSL/TLS ***

Generating DH parameters, 512 bit long safe prime, generator 2

This is going to take a long time

.............+...............................+...................................................+...++

*++*++*++*++*++*

checking for Kerberos include files... could not find include files

checking for perl... /usr/bin/perl

configure: creating ./config.status

config.status: creating Makefile

config.status: creating src/Makefile

config.status: creating subst

config.status: creating include/config.h

*** Configuration summary for nrpe 2.13 11-11-2011 ***:

General Options:

-------------------------

NRPE port: 5666

NRPE user: nagios

NRPE group: nagios

Nagios user: nagios

Nagios group: nagios

Review the options above for accuracy. If they look okay,

type 'make all' to compile the NRPE daemon and client.

[root@localhost nrpe-2.13]#

Ahora ejecutamos make all

[root@localhost nrpe-2.13]# make all

cd ./src/; make ; cd ..

make[1]: Entering directory `/root/Downloads/nrpe-2.13/src'

gcc -g -O2 -I/usr/include/openssl -I/usr/include -DHAVE_CONFIG_H -o nrpe nrpe.c utils.c acl.c -

L/usr/lib -lssl -lcrypto -lnsl

nrpe.c: In function ‘main’:

nrpe.c:218: warning: assignment discards qualifiers from pointer target type

gcc -g -O2 -I/usr/include/openssl -I/usr/include -DHAVE_CONFIG_H -o check_nrpe check_nrpe.c utils.c -

L/usr/lib -lssl -lcrypto -lnsl

check_nrpe.c: In function ‘main’:

check_nrpe.c:126: warning: assignment discards qualifiers from pointer target type

make[1]: Leaving directory `/root/Downloads/nrpe-2.13/src'

*** Compile finished ***

If the NRPE daemon and client compiled without any errors, you

can continue with the installation or upgrade process.

Read the PDF documentation (NRPE.pdf) for information on the next

steps you should take to complete the installation or upgrade.


Ahora make install-plugin

[root@localhost nrpe-2.13]# make install-plugin

cd ./src/ && make install-plugin


/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/libexec

/usr/bin/install -c -m 775 -o nagios -g nagios check_nrpe /usr/local/nagios/libexec



Ahora make install-daemon

[root@localhost nrpe-2.13]# make install-daemon

cd ./src/ && make install-daemon


/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/bin

/usr/bin/install -c -m 775 -o nagios -g nagios nrpe /usr/local/nagios/bin



Ahora make install-daemon-config

[root@localhost nrpe-2.13]# make install-daemon-config

/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc

/usr/bin/install -c -m 644 -o nagios -g nagios sample-config/nrpe.cfg /usr/local/nagios/etc


Ahora make install-xinetd

[root@localhost nrpe-2.13]# make install-xinetd

/usr/bin/install -c -m 644 sample-config/nrpe.xinetd /etc/xinetd.d/nrpe


Editar (sacar un backup) el archivo /etc/xinetd.d/nrpe y agragar la IP de nuestro servidor nagios (con el

core) que es 192.168.1.2.

# default: on

# description: NRPE (Nagios Remote Plugin Executor)

service nrpe

{

flags = REUSE

socket_type = stream

port = 5666

wait = no

user = nagios

group = nagios

server = /usr/local/nagios/bin/nrpe

server_args = -c /usr/local/nagios/etc/nrpe.cfg --inetd

log_on_failure += USERID

disable = no

only_from = 127.0.0.1 192.168.1.2

}

Editar el archivo /etc/services y agregar en la última línea “nrpe 5666/tcp # NRPE ”

blp5 48129/udp # Bloomberg locator

com-bardac-dw 48556/tcp # com-bardac-dw

com-bardac-dw 48556/udp # com-bardac-dw

iqobject 48619/tcp # iqobject

iqobject 48619/udp # iqobject

nrpe 5666/tcp # NRPE

Ahora reiniciar el servicio xinetd y verificar que nrpe está escuchando:

[root@localhost nrpe-2.13]# service xinetd restart

Stopping xinetd: [ OK ]

Starting xinetd: [ OK ]

[root@localhost nrpe-2.13]# netstat -at | grep nrpe

tcp 0 0 *:nrpe *:* LISTEN


Ahora sí a probar (PERO DESDE EL MISMO HOST):

Vemos los dispositivos que tenemos:

[root@localhost nagios-plugins-1.4.16]# fdisk -l

Disk /dev/sda: 17.2 GB, 17179869184 bytes

255 heads, 63 sectors/track, 2088 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x0009ba81

Device Boot Start End Blocks Id System

/dev/sda1 * 1 64 512000 83 Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2 64 2089 16264192 8e Linux LVM

Disk /dev/mapper/VolGroup-lv_root: 15.3 GB, 15342764032 bytes





Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_root doesn't contain a valid partition table

Disk /dev/mapper/VolGroup-lv_swap: 1308 MB, 1308622848 bytes






Disk /dev/mapper/VolGroup-lv_swap doesn't contain a valid partition table

[root@localhost nagios-plugins-1.4.16]#

Ahora vemos el estado del /dev/sda:

[root@localhost nagios-plugins-1.4.16]# /usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda

DISK OK - free space: / 9172 MB (67% inode=88%);| /=4498MB;11521;12961;0;14402

[root@localhost nagios-plugins-1.4.16]#

El comando anterior establece que devuelva un advertencia (-w) si el disco está a menos de 20% de

espacio libre y Crítico (-c) si a menos de 10%.

IMPORTANTE: HABILITAR EL PUERTO 5666/TCP en el cortafuegos. !!!!

para poder hacer

[root@localhost nagios-plugins-1.4.16]# /usr/local/nagios/libexec/check_nrpe -H 192.168.1.4

NRPE v2.13


NRPE v2.13

Sino sale “connection refused or time out” o esto:


CHECK_NRPE: Error - Could not complete SSL handshake.

# default: on


service nrpe

{

disable = no

flags = REUSE


port = 5666

wait = no

user = nagios

group = nagios




only_from = 192.168.1.2 127.0.0.1 192.168.1.4

}

CONFIGURACIONES PARA EN SERVIDOR NAGIOS (que va a monitorear)

Instalar el core-nagios, el nagios-plugins , el nrpe y MUY IMPORTANTE antes de todo eso instalar el

openssl-devel con yum install (se instalan sus dependencias) ya que este openssl-devel hace que no

salgan los errores al hacer make o make install en los paquetes nahios-plugibns y nrpe.

Igual se configuran los archivos /etc/xinetd.d/nrpe y /etc/services como se ve arriba y SE HABILITA

EL PUERTO 5666 EN EL MURO CORTAFUEGOS y se reinicia el servcicio xinetd.

A esta altura se puede hacer a y desde el servidor:


NRPE v2.13

Lo anterior se hace desde el servidor a ser monitorizado (192.168.1.2) al servidor nagios (192.168.1.4)

comprobando que se pueda establecer conexión.

MONITOREANDO DESDE EL SERVIDOR NAGIOS a un servidor linux

Abrir la interfaz web de nagios como http://<ip del servidor nagios ó nombre>/nagios/

Para solucioanr el problema de que ingún link de la izquierda funca (aparece eso de “The server

encountered an internal error or misconfiguration...”) salvo dos (home y documentation)

ejecutar el comando:

[root@localhost nagios-plugins-1.4.16]# chcon -R -t httpd_sys_content_t /usr/local/nagios

Ahora sí se puede observar información y gráficos en la interfaz de nagios:

AHORA SÍ MONITOREMOS ALGO

MONITOREANDO A OTRO HOST CON CENTOS COMO SO

Supongamos que queremos monitorear un servidor con CentOS 6.2 de IP 192.168.1.2 desde otro

equipo monitorizador con nagios (y nrpe) instalado de IP 192.168.1.4.

Digamos que vamos a chequear el disco del otro equipo:

En el servidor nagios (monitorizador)

Definir el comando a usar para checar el disco:

[root@nagios Desktop]# gedit /usr/local/nagios/etc/nrpe.cfg

Agregar la línea al final del archivo:

command[check_disk]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda

Definir un comando, para ello:

[root@nagios Desktop]# gedit /usr/local/nagios/etc/objects/commands.cfg

Y definir un comando como el siguiente (agregarlo al último): define command{

command_name check_nrpe

command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$

}

define command{

command_name check_disk

command_line $USER1$/check_disk -w 20% -c 10% -p /dev/sda

}

NOTA:

/dev/mapper/sda puede variar, representa la unidad de disco , “la que vamos a monitorear”. Para saber

cuál unidad o partición monitorear se puede ejecutar el comando (EN EL HOST REMOTO):

[root@nagios Desktop]# fdisk -l

Disk /dev/sda: 17.2 GB, 17179869184 bytes





Disk identifier: 0x0009ba81

Device Boot Start End Blocks Id System

/dev/sda1 * 1 64 512000 83 Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2 64 2089 16264192 8e Linux LVM

Disk /dev/mapper/VolGroup-lv_root: 15.3 GB, 15342764032 bytes






Disk /dev/mapper/VolGroup-lv_root doesn't contain a valid partition table

Disk /dev/mapper/VolGroup-lv_swap: 1308 MB, 1308622848 bytes






Disk /dev/mapper/VolGroup-lv_swap doesn't contain a valid partition table

[root@nagios Desktop]#

(En el equipo monitorizador ) crear un archivo en /usr/local/nagios/etc/objects/ con extensión .cfg

por ejemplo: /usr/local/nagios/etc/objects/srvremoto.cfg y agregar lo siguiente:

define host{

use linux-server

host_name dns1.midominio.com.ec

alias servidor de midominio.com.ec

address 192.168.1.2

contact_groups admins

}

define service{

use generic-service

host dns1.midominio.com.ec

service_description Disco duro


check_command check_nrpe!check_disk

}

En el archivo más o menos por la línea 37 añadir la línea:

cfg_file=/usr/local/nagios/etc/objects/srvremoto.cfg

Reiniciar el servicio nagios y xinetd

En el equipo a monitorizar

Sabíamos que en el archivo /etc/xinetd.d/nrpe debe estar la IP de nuestro servidor nagios (con el core)

que es 192.168.1.2.

# default: on


service nrpe

{

flags = REUSE


port = 5666

wait = no

user = nagios

group = nagios




disable = no

only_from = 127.0.0.1 192.168.1.2

}

IMPORTANTE:

Agregar la misma línea en el host remoto en el mismo archivo (reiniciar xinetd y nagios)

Definir el comando a usar para checar el disco:

[root@nagios Desktop]# gedit /usr/local/nagios/etc/nrpe.cfg

Agregar la línea al final del archivo:

command[check_disk]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda

Reiniciar nagios y xinetd (porsiaca)

[root@nagios Desktop]# service nagios restart

Running configuration check...done.

Stopping nagios: done.

Starting nagios: done.

[root@nagios Desktop]# service xinetd restart

Stopping xinetd: [ OK ]

Starting xinetd: [ OK ]

[root@nagios Desktop]#

Y LISTO

En este punto ya podemos checar en la interface web:

Para chequear smtp

En el servidor nagios (monitorizador)

Agregar al archivo srvremoto.cfg

define service{

use generic-service

host dns1.midominio.com.ec

service_description SMTP


check_command check_nrpe!check_smtp

}

Y en el archivo nrpe.cfg

command[check_smtp]=/usr/local/nagios/libexec/check_smtp -w 10 -c 5

reiniciar xinetd y nagios

En el equipo a monitorizar:

En el archivo nrpe.cfg

command[check_smtp]=/usr/local/nagios/libexec/check_smtp -w 10 -c 5

reiniciar xinetd y nagios

Y se puede ver:

Date post:	01-Dec-2015
Category:	Documents
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