NaGIOS 4: UBUNTU 20.04 instalasi NaGIOS
Nagios adalah sistem pemantauan open-source yang populer. Nagios menjaga inventory server anda dan memonitor mereka sehingga anda tahu layanan penting anda sudah up dan running. Menggunakan sistem pemantauan seperti Nagios adalah tool penting untuk lingkungan produksi apa pun, karena dengan memantau waktu kerja, penggunaan CPU, atau disk space, anda dapat mencegah masalah sebelum terjadi, atau sebelum pengguna anda menghubungi anda.
Disini kita akan menginstalasi Nagios 4 dan mengkonfigurasinya agar kita dapat memonitor resource host di interface web Nagios. Kita juga akan mensetup Nagios Remote Plugin Executor (NRPE), yang akan berjalan sebagai agent remote host sehingga kita dapat memonitor resource-nya.
Kebutuhan
- Dua Ubuntu 20.04 server dengan user root privige. Firewall dengan ufw.
- Server dengan Nagios akan di sebut Nagios server.
- Server tanpa Nagios akan di sebut Ubuntu server.
- Nagios Server akan menjalakan Apache dan PHP.
Nagios Server biasanya di jalankan di belakang Firewall atau VPN. Jika di jalankan di IP Public anda harus lebih serius menginstalasi TLS/SSL dll. Tutorial ini berasumsi, Nagios server di belakang Firewall.
Step 1 — Installing Nagios 4
Login ke Nagios server,
ssh username@your_nagios_server_ip
Instalasi aplikasi pendukung,
sudo apt update sudo apt -y install autoconf gcc libc6 make wget unzip apache2 php libapache2-mod-php libgd-dev # sudo apt -y install autoconf gcc make unzip libgd-dev libmcrypt-dev libssl-dev dc snmp libnet-snmp-perl gettext
Download source code terakhir Nagios (misalnya),
cd /usr/local/src/ wget -O nagioscore.tar.gz https://github.com/NagiosEnterprises/nagioscore/archive/nagios-4.4.6.tar.gz tar xzf nagioscore.tar.gz cd /usr/local/src/nagioscore-nagios-4.4.6/
Run script & specify Apache config directory:
sudo su cd /usr/local/src/nagioscore-nagios-4.4.6/ sudo ./configure --with-httpd-conf=/etc/apache2/sites-enabled
Catatan: jika kita menggunakan email server postfix, ada baiknya di tambah --with-mail=/usr/sbin/sendmail
Compile & install Nagios,
cd /usr/local/src/nagioscore-nagios-4.4.6/ sudo make all sudo make install-groups-users sudo make install sudo make install-daemoninit sudo make install-commandmode sudo make install-config
Konfigurasi apache
sudo make install-webconf sudo a2enmod rewrite sudo a2enmod cgi sudo usermod -a -G nagios www-data
Konfigurasi & masukan _PASSWORD_ untuk user nagiosadmin (untuk user lain, nagiosadmin bisa di ganti)
sudo htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Catatan: edit /usr/local/nagios/etc/cgi.cfg ubah nagiosadmin ke useranda jika tidak menggunakan nagiosadmin.
Restart Apache,
sudo systemctl restart apache2
Step 2 — Installing Nagios Plugins
Kita perlu menginstalasi Nagios plugin, ada sekitar 50 plugin untuk memonitor berbagai hal seperti uptime, disk usage, swap usage, NTP dll. Download plugin,
sudo su cd /usr/local/src curl -L -O https://nagios-plugins.org/download/nagios-plugins-2.3.3.tar.gz tar zxf nagios-plugins-2.3.3.tar.gz cd /usr/local/src/nagios-plugins-2.3.3
Konfigurasi & instalasi:
cd /usr/local/src/nagios-plugins-2.3.3 ./configure sudo make sudo make install
Step 3 — Installing the check_nrpe Plugin
Nagios me-monitor remote host menggunakan Nagios Remote Plugin Executor (NRPE). NRPE terdiri dari dua bagian,
- check_nrpe plugin (di admin console) yang digunakan di Nagios server.
- NRPE daemon, di remote host dan mengirimkan data ke Nagios server.
Optional untuk mencari kesiapan libssl-dev
apt -y install apt-file apt-file update apt-file search libssl | grep libssl-dev apt-file search libssl | grep /usr/lib/x86_64-linux-gnu apt-file search ssl | grep /usr/bin/openssl
Install libssl-dev
apt -y install libssl-dev
Download,
sudo su cd /usr/local/src curl -L -O https://github.com/NagiosEnterprises/nrpe/releases/download/nrpe-4.0.3/nrpe-4.0.3.tar.gz tar zxf nrpe-4.0.3.tar.gz cd /usr/local/src/nrpe-4.0.3
Konfigurasi dan install check_nrpe plugin:
sudo su cd /usr/local/src/nrpe-4.0.3 ./configure --with-ssl=/usr/bin/openssl --with-ssl-lib=/usr/lib/x86_64-linux-gnu sudo make check_nrpe sudo make install-plugin
Step 4 — Konfigurasi Nagios server
Konfigurasi awal Nagios, meliputi proses editing beberapa file konfigurasi. Kita hanya perlu melakukannya satu kali di Nagios server.
Edit nagios.cfg
sudo vi /usr/local/nagios/etc/nagios.cfg
Temukan di /usr/local/nagios/etc/nagios.cfg
... #cfg_dir=/usr/local/nagios/etc/servers ...
Buang # di depan cfg_dir, menjadi
cfg_dir=/usr/local/nagios/etc/servers
Buat directory tersebut. Ini akan menyimpan file konfigurasi untuk setiap server yang kita monitor,
sudo mkdir -p /usr/local/nagios/etc/servers
Edit contact
sudo vi /usr/local/nagios/etc/objects/contacts.cfg
Ubah email dengan email kita di /usr/local/nagios/etc/objects/contacts.cfg
...
define contact{
contact_name nagiosadmin ; Short name of user
use generic-contact ; Inherit default values from generic-contact template (defined above)
alias Nagios Admin ; Full name of user
email your_email@your_domain.com ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******
...
Edit commands.cfg'
Untuk menambahkan new command ke konfigurasi Nagios.
sudo vi /usr/local/nagios/etc/objects/commands.cfg
Tambahkan di /usr/local/nagios/etc/objects/commands.cfg
...
define command{
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}
Restart Nagios
sudo systemctl start nagios
Step 5 — Akses Nagios Web
Akses ke
http://nagios_server_public_ip/nagios.
username nagiosadmin password yangkitasetsebelumnya
Untuk melihat host yang di monitor, kita bisa klik menu
Current Status > Hosts
Terlihat default Nagios hanya memonitor localhost
Step 6 — Installing Nagios Plugin & NRPE Daemon di Server yang di monitor
Untuk memonitor sebuah server, kita perlu menginstalasi Nagios Remote Plugin Executor (NRPE) di remote host tersebit, install plugin, dan konfigurasi Nagios server.
Login server yang akan di monitor,
ssh onno@your_monitored_server_ip
Buat user nagios yang akan menjalankan NRPE agent,
sudo useradd nagios
Install aplikasi pendukung,
sudo apt update sudo apt -y install autoconf gcc libmcrypt-dev make libssl-dev wget dc build-essential gettext
Download Nagios Plugins,
sudo su cd /usr/local/src curl -L -O https://nagios-plugins.org/download/nagios-plugins-2.3.3.tar.gz tar zxf nagios-plugins-2.3.3.tar.gz cd /usr/local/src/nagios-plugins-2.3.3
Compile & install
./configure sudo make sudo make install
Install NRPE daemon,
cd /usr/local/src curl -L -O https://github.com/NagiosEnterprises/nrpe/releases/download/nrpe-4.0.3/nrpe-4.0.3.tar.gz tar zxf nrpe-4.0.3.tar.gz cd /usr/local/src/nrpe-4.0.3
Configure & Install NRPE:
cd /usr/local/src/nrpe-4.0.3 ./configure sudo make nrpe sudo make install-daemon sudo make install-config sudo make install-init
Untuk ujicoba kita akan monitor penggunan harddisk. Contoh,
df -h /
Akan keluar,
Filesystem Size Used Avail Use% Mounted on /dev/sda2 40G 5.0G 33G 14% /
Edit /usr/local/nagios/etc/nrpe.cfg
sudo vi /usr/local/nagios/etc/nrpe.cfg
Kita perlu menembukan dan mengubah,
server_address: Set to the private IP address of the monitored server. allowed_hosts: Add the private IP address of your Nagios server to the comma-delimited list. command[check_hda1]: Change /dev/hda1 to whatever your root filesystem is called.
Locate these settings and alter them appropriately:
/usr/local/nagios/etc/nrpe.cfg
... server_address=second_ubuntu_server_private_ip ... allowed_hosts=127.0.0.1,::1,your_nagios_server_private_ip ... command[check_sda2]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda2 ...
Start NRPE,
sudo systemctl start nrpe.service
Pastikan running,
sudo systemctl status nrpe.service
output kira2,
... Aug 01 06:28:31 client systemd[1]: Started Nagios Remote Plugin Executor. Aug 01 06:28:31 client nrpe[8021]: Starting up daemon Aug 01 06:28:31 client nrpe[8021]: Server listening on 0.0.0.0 port 5666. Aug 01 06:28:31 client nrpe[8021]: Server listening on :: port 5666. Aug 01 06:28:31 client nrpe[8021]: Listening for connections on port 5666 Aug 01 06:28:31 client nrpe[8021]: Allowing connections from: 127.0.0.1,::1,165.22.212.38
Buka port 5666 di firewall,
sudo ufw allow 5666/tcp
Cek komunikasi ke remote NRPE server dari Admin Console (Nagios Server),
/usr/local/nagios/libexec/check_nrpe -H second_ubuntu_server_ip
Output,
NRPE v4.0.3
Step 7 — Monitoring Hosts dengan Nagios
Tambahkan host yang akan di monitor Nagios, edit
sudo vi /usr/local/nagios/etc/servers/your_monitored_server_host_name.cfg sudo vi /usr/local/nagios/etc/servers/192.168.0.155.cfg
Edit file /usr/local/nagios/etc/servers/your_monitored_server_host_name.cfg
define host {
use linux-server
host_name your_monitored_server_host_name
alias My client server
address your_monitored_server_private_ip
max_check_attempts 5
check_period 24x7
notification_interval 30
notification_period 24x7
}
Tambahkan service yang di monitor
sudo vi /usr/local/nagios/etc/servers/your_monitored_server_host_name.cfg sudo vi /usr/local/nagios/etc/servers/192.168.0.155.cfg
define service {
use generic-service
host_name your_monitored_server_host_name
service_description Load average
check_command check_nrpe!check_load
}
Cek Disk
sudo vi /usr/local/nagios/etc/servers/your_monitored_server_host_name.cfg sudo vi /usr/local/nagios/etc/servers/192.168.0.155.cfg
define service {
use generic-service
host_name your_monitored_server_host_name
service_description /dev/sda2 free space
check_command check_nrpe!check_sda2
}
Save & Quit.
Restart,
sudo systemctl restart nagios
Tunggu beberapa menit, cek kembali ke Nagios Web.
Referensi