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Step 1 - Install icinga2 in Agent Server
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8  apt update
9  apt -y install apt-transport-https wget gnupg
10  wget -O - https://packages.icinga.com/icinga.key | gpg --dearmor -o /usr/share/keyrings/icinga-archive-keyring.gpg
11  . /etc/os-release; if [ ! -z ${UBUNTU_CODENAME+x} ]; then DIST="${UBUNTU_CODENAME}"; else DIST="$(lsb_release -c| awk '{print $2}')"; fi;  echo "deb [signed-by=/usr/share/keyrings/icinga-archive-keyring.gpg] https://packages.icinga.com/ubuntu icinga-${DIST} main" >  /etc/apt/sources.list.d/${DIST}-icinga.list
12  apt update
13  apt install icinga2
14  apt install monitoring-plugins
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Step 2 - Enable icinga2 Agent
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root@ip-172-31-4-57:~# icinga2 node wizard
Welcome to the Icinga 2 Setup Wizard!
We will guide you through all required configuration details.
Please specify if this is an agent/satellite setup ('n' installs a master setup)                                                                               [Y/n]: Y
Starting the Agent/Satellite setup routine...
Please specify the common name (CN) [ip-172-31-4-57.ap-south-1.compute.internal]:
Please specify the parent endpoint(s) (master or satellite) where this node should connect to:
Master/Satellite Common Name (CN from your master/satellite node): ip-172-31-12-175.ap-south-1.compute.i                                                      nternal
Do you want to establish a connection to the parent node from this node? [Y/n]: Y
Please specify the master/satellite connection information:
Master/Satellite endpoint host (IP address or FQDN): 172.31.12.175
Master/Satellite endpoint port [5665]:
Add more master/satellite endpoints? [y/N]: N
Parent certificate information:
Version:             3
Subject:             CN = ip-172-31-12-175.ap-south-1.compute.internal
Issuer:              CN = Icinga CA
Valid From:          May 10 04:17:19 2024 GMT
Valid Until:         Jun 11 04:17:19 2025 GMT
Serial:              f0:c6:d1:1c:f0:78:1b:6b:2d:7c:20:4b:1b:50:3c:be:f0:25:a2:17
Signature Algorithm: sha256WithRSAEncryption
Subject Alt Names:   ip-172-31-12-175.ap-south-1.compute.internal
Fingerprint:         54 FD AD AC 55 39 7F 7A 5F C2 2D BB 09 22 BE 43 08 15 FB DF 0D F6 5C 2B 76 15 0F C                                                      1 DD 29 00 7B
Is this information correct? [y/N]: y
Please specify the request ticket generated on your Icinga 2 master (optional).
(Hint: # icinga2 pki ticket --cn 'ip-172-31-4-57.ap-south-1.compute.internal'): 94deed8004eefccb459689dbc6fe1112543b01eb
Please specify the API bind host/port (optional):
Bind Host []:
Bind Port []:
Accept config from parent node? [y/N]: y
Accept commands from parent node? [y/N]: y
Reconfiguring Icinga...
Disabling feature notification. Make sure to restart Icinga 2 for these changes to take effect.
Enabling feature api. Make sure to restart Icinga 2 for these changes to take effect.
Local zone name [ip-172-31-4-57.ap-south-1.compute.internal]:
Parent zone name [master]:
Default global zones: global-templates director-global
Do you want to specify additional global zones? [y/N]:
Do you want to disable the inclusion of the conf.d directory [Y/n]: n
Done.
Now restart your Icinga 2 daemon to finish the installation!\
$ systemctl restart icinga2
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Step 3 - Install Apache 2
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26  apt-get update
27  apt install apache2
28  clear
29  ls
30  systemctl start apache2
31  systemctl status apache2
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Step 4 - Verify if Mod_Staus module in Apache2
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$ ls /etc/apache2/mods-enabled | grep status*
status.conf
status.load
$ sudo /usr/sbin/a2enmod status
Module status already enabled
Note - If you want to enable - follow this - https://www.devopsschool.com/blog/how-to-install-mod_status-on-your-apache-servers-and-enable-extendedstatus/
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Step 5 - Enable Mod Status Module from icinga server
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$ more /etc/apache2/mods-enabled/status.conf
$ vi /etc/apache2/mods-enabled/status.conf
$ systemctl restart apache2
<IfModule mod_status.c>
# Allow server status reports generated by mod_status,
# with the URL of http://servername/server-status
# Uncomment and change the "192.0.2.0/24" to allow access from other hosts.
<Location /server-status>
SetHandler server-status
Require local
Require ip 172.31.12.175
</Location>
# Keep track of extended status information for each request
ExtendedStatus On
# Determine if mod_status displays the first 63 characters of a request or
# the last 63, assuming the request itself is greater than 63 chars.
# Default: Off
#SeeRequestTail On
<IfModule mod_proxy.c>
# Show Proxy LoadBalancer status in mod_status
ProxyStatus On
</IfModule>
</IfModule>
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Step 6 - Enable Apache check in Icinga Server
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49  cd /etc/icinga2/conf.d/
50  ls
51  vi commands.conf
object CheckCommand "check_apache_status" {
import "plugin-check-command"
command = [ PluginDir + "/check_http" ]
arguments = {
"-H" = "$address$"
"-u" = "/server-status?auto"
}
}
OR
object CheckCommand "check_apache_status" {
import "plugin-check-command"
command = [ PluginDir + "/check_http" ]
arguments = {
"-H" = "172.31.4.57"
"-u" = "/server-status?auto"
}
}
$ systemctl restart icinga2
$ systemctl status icinga2
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