https://docs.icinga.com/icinga2/latest/doc/module/icinga2/chapter/getting-started https://github.com/Icinga/icingaweb2/blob/master/doc/02-Installation.md

icinga2

yum install https://packages.icinga.org/epel/6/release/noarch/icinga-rpm-release-6-1.el6.noarch.rpm
yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm

yum install icinga2 -y
yum install httpd mysql-server mysql -y
yum install -y icinga2-ido-mysql
yum install -y icinga-web
yum install -y openssl-devel
yum install -y icinga2-ido-mysql icinga-idoutils-libdbi-mysql
yum install -y gcc # required for later plugin compilation
yum install -y mailx # required for sending notifications
yum install -y php-mysql #could be already there due to depencies.
yum install -y nagios-plugins-all

chkconfig icinga2
chkconfig httpd on
chkconfig mysqld on

service mysqld start
service httpd start
service icinga2 start

mysql_secure_installation

mysql -u root -p
CREATE DATABASE icinga;
GRANT SELECT, INSERT, UPDATE, DELETE, DROP, CREATE VIEW, INDEX, EXECUTE ON icinga.* TO 'icinga'@'localhost' IDENTIFIED BY 'password';
quit
mysql -u root -p icinga < /usr/share/icinga2-ido-mysql/schema/mysql.sql

iptables -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
service iptables save
set enforce 0

icigaweb2

yum install icingaweb2 icingacli
http://127.0.0.1/icingaweb2/setup
icingacli setup config directory --group icingaweb2;
icingacli setup token create;
The newly generated setup token is: xxxxxxxx

/etc/php.ini
;date.timezone = UTC
setenforce 0

touch /var/www/html/index.html

icingaweb2 websetup

http://www.2daygeek.com/install-icinga-web2-on-centos-rhel-fedora-opensuse-ubuntu-debian-mint/5/

icinga command

icinga2 feature enable command

icinga cli

/etc/init.d/icinga2 checkconfig
/etc/init.d/icinga2 reload
icinga2 object list --type Service --name ping

icinga api

icinga2 api setup
/etc/init.d/icinga2 reload

curl -k -s -u root:icinga -H 'Accept: application/json' -X PUT 'https://localhost:5665/v1/objects/hosts/ou-host'
-d '{ "templates": [ "generic-host" ], "attrs": { "address": "[ip]", "check_command": "hostalive", "vars.os" : "Linux" } }'
| python -m json.tool

curl -k -s -u root:icinga -H 'Accept: application/json' -X PUT 'https://localhost:5665/v1/objects/hosts/ou-dns'
-d '{ "templates": [ "generic-host" ], "attrs": { "address": "[ip]" } }'
| python -m json.tool

$ curl -k -s -u root:icinga -H 'Accept: application/json' -X PUT 'https://localhost:5665/v1/objects/services/localhost!realtime-load' <br> -d '{ "templates": [ "generic-service" ], "attrs": { "check_command": "load", "check_interval": 1,"retry_interval": 1 } }'
Example for a new CheckCommand object:

$ curl -k -s -u root:icinga -H 'Accept: application/json' -X PUT 'https://localhost:5665/v1/objects/checkcommands/mytest'
-d '{ "templates": [ "plugin-check-command" ], "attrs": { "command": [ "/usr/local/sbin/check_http" ], "arguments": { "-I": "$mytest_iparam$" } } }'

$ curl -k -s -u root:icinga -H 'Accept: application/json' -X POST 'https://localhost:5665/v1/objects/hosts/example.localdomain' <br> -d '{ "attrs": { "address": "192.168.1.2", "vars.os" : "Windows" } }' <br> | python -m json.tool
{ "results": [ { "code": 200.0, "name": "example.localdomain", "status": "Attributes updated.", "type": "Host" } ] }

$ curl -k -s -u root:icinga -H 'Accept: application/json' -X DELETE 'https://localhost:5665/v1/objects/hosts/example.localdomain?cascade=1' | python -m json.tool
{ "results": [ { "code": 200.0, "name": "example.localdomain", "status": "Object was deleted.", "type": "Host" } ] }

postgresql installation

RHEL/CentOS 5/6:
yum install postgresql-server postgresql
chkconfig postgresql on
service postgresql start
RHEL/CentOS 7:
yum install postgresql-server postgresql
postgresql-setup initdb
systemctl enable postgresql
systemctl start postgresql