apt-cache policy icinga2 icingaweb2 | head -14

icinga2:
  Installed: (none)
  Candidate: 2.16.5-1+ubuntu22.04
  Version table:
     2.16.5-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
     2.16.4-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
     2.16.3-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
     2.16.2-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
     2.16.1-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages

apt-cache policy icingaweb2 | head -6

icingaweb2:
  Installed: (none)
  Candidate: 2.12.7-1+ubuntu22.04
  Version table:
     2.12.7-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
     2.12.6-1+ubuntu22.04 500
        500 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages

export DEBIAN_FRONTEND=noninteractive
apt-get update
apt-get install -y gnupg curl apt-transport-https ca-certificates mariadb-server monitoring-plugins

systemctl start mariadb
systemctl is-active mariadb
mariadb --version
mysqladmin --version

active
mariadb  Ver 15.1 Distrib 10.6.23-MariaDB, for debian-linux-gnu (x86_64) using  EditLine wrapper
mysqladmin  Ver 10.0 Distrib 10.6.23-MariaDB, for debian-linux-gnu on x86_64

curl -fsSL https://packages.icinga.com/icinga.key | gpg --dearmor -o /usr/share/keyrings/icinga-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/icinga-archive-keyring.gpg] https://packages.icinga.com/ubuntu icinga-jammy main" > /etc/apt/sources.list.d/icinga.list
apt-get update

Get:5 https://packages.icinga.com/ubuntu icinga-jammy InRelease [9149 B]
Get:6 https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages [142 kB]

gpg --show-keys --with-colons /usr/share/keyrings/icinga-archive-keyring.gpg | head -4

pub:-:4096:1:CC116F55AA7F2382:1716285309:::-:::scSC::::::23::0:
fpr:::::::::DD3AF6198ED000B4C0B73956CC116F55AA7F2382:
uid:-::::1716285309::F8C6CE97CC9FFBB3F473055DF12D5F1F2D708D45::Icinga GmbH (Build server) <info@icinga.com>::::::::::0:

export DEBIAN_FRONTEND=noninteractive
apt-get install -y icinga2 icinga2-ido-mysql

creating database icinga2: success.
verifying database icinga2 exists: success.
populating database via sql...  done.
dbconfig-common: flushing administrative password
Setting up icinga2 (2.16.5-1+ubuntu22.04) ...
Processing triggers for libc-bin (2.35-0ubuntu3.15) ...
INSTALL_EXIT=0

grep -E "dbuser|dbpass|dbname" /etc/dbconfig-common/icinga2-ido-mysql.conf

dbc_dbuser='icinga2'
dbc_dbpass='pqpoHefgqTVT'
dbc_dbname='icinga2'

library "db_ido_mysql"
object IdoMysqlConnection "ido-mysql" {
  user = "icinga2",
  password = "pqpoHefgqTVT",
  host = "localhost",
  database = "icinga2"
}

mariadb -e "ALTER USER 'icinga2'@'localhost' IDENTIFIED BY 'q1w2e3r4'; FLUSH PRIVILEGES;"
sed -i 's/pqpoHefgqTVT/q1w2e3r4/' /etc/icinga2/features-available/ido-mysql.conf

icinga2 feature enable ido-mysql
icinga2 feature enable api
systemctl enable icinga2
systemctl restart icinga2

Enabling feature ido-mysql. 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.

Job for icinga2.service failed because the control process exited with error code.
See "systemctl status icinga2.service" and "journalctl -xeu icinga2.service" for details.
failed

journalctl -u icinga2 --no-pager -n 15 | grep -E "critical"

critical/SSL: Error on bio X509 AUX reading pem file '/var/lib/icinga2/certs//icinga1.example.com.crt': 2147483650, "error:80000002:system library::No such file or directory"
critical/config: Error: Cannot get certificate from cert path: '/var/lib/icinga2/certs//icinga1.example.com.crt'.
critical/config: 1 error
critical/cli: Config validation failed. Re-run with 'icinga2 daemon -C' after fixing the config.

icinga2 api setup

information/cli: Adding new ApiUser 'root' in '/etc/icinga2/conf.d/api-users.conf'.
information/cli: Reading '/etc/icinga2/icinga2.conf'.
information/cli: Enabling the 'api' feature.
warning/cli: Feature 'api' already enabled.
information/cli: Updating 'NodeName' constant in '/etc/icinga2/constants.conf'.
information/cli: Created backup file '/etc/icinga2/constants.conf.orig'.
information/cli: Updating 'ZoneName' constant in '/etc/icinga2/constants.conf'.
information/cli: Backup file '/etc/icinga2/constants.conf.orig' already exists. Skipping backup.
Done.

Now restart your Icinga 2 daemon to finish the installation!

ca.crt
icinga1.example.com.crt
icinga1.example.com.csr
icinga1.example.com.key

sed -i 's/password = "03e66d029c2c98cd"/password = "q1w2e3r4"/' /etc/icinga2/conf.d/api-users.conf

systemctl restart icinga2
systemctl is-active icinga2
ss -ltnp | grep 5665
systemctl status icinga2 --no-pager -l | head -12

active
LISTEN 0      4096               *:5665             *:*    users:(("icinga2",pid=8800,fd=18))
● icinga2.service - Icinga host/service/network monitoring system
     Loaded: loaded (/lib/systemd/system/icinga2.service; enabled; vendor preset: enabled)
    Drop-In: /etc/systemd/system/icinga2.service.d
             └─limits.conf
     Active: active (running) since Mon 2026-10-19 20:25:08 UTC; 4min 56s ago
   Main PID: 8758 (icinga2)
     Status: "Startup finished."
      Tasks: 89
     Memory: 22.9M
        CPU: 13.671s

icinga2 daemon -C

[2026-10-19 20:30:04 +0000] information/ConfigItem: Instantiated 3 ServiceGroups.
[2026-10-19 20:30:04 +0000] information/ConfigItem: Instantiated 3 TimePeriods.
[2026-10-19 20:30:04 +0000] information/ConfigItem: Instantiated 12 Services.
[2026-10-19 20:30:04 +0000] information/ConfigItem: Instantiated 1 ScheduledDowntime.
[2026-10-19 20:30:04 +0000] information/ScriptGlobal: Dumping variables to file '/var/cache/icinga2/icinga2.vars'
[2026-10-19 20:30:04 +0000] information/cli: Finished validating the configuration file(s).

icinga2 feature list

Disabled features: command compatlog debuglog elasticsearch gelf graphite icingadb influxdb influxdb2 journald livestatus opentsdb perfdata syslog
Enabled features: api checker ido-mysql mainlog notification

curl -sk -u root:q1w2e3r4 -X GET "https://localhost:5665/v1/status/IcingaApplication"

{"results":[{"name":"IcingaApplication","perfdata":[],"status":{"icingaapplication":{"app":{"enable_event_handlers":true,"enable_flapping":true,"enable_host_checks":true,"enable_notifications":true,"enable_perfdata":true,"enable_service_checks":true,"environment":"","node_name":"icinga1.example.com","pid":8800,"program_start":1792441508.364058,"version":"r2.16.5-1"}}}}]}

mariadb icinga2 -e "SELECT o.name1 AS host, hs.current_state, hs.output, hs.status_update_time FROM icinga_hoststatus hs JOIN icinga_objects o ON o.object_id=hs.host_object_id AND o.objecttype_id=1;"

host    current_state   output  status_update_time
icinga1.example.com     0       PING OK - Packet loss = 0%, RTA = 0.04 ms       2026-10-19 20:30:09

mkdir -p /root/debs && cd /root/debs
apt-get download icinga2 icinga2-bin icinga2-common
ls -lh

total 5.0M
-rw-r--r-- 1 root root 4.8M Aug 18 08:10 icinga2-bin_2.16.5-1+ubuntu22.04_amd64.deb
-rw-r--r-- 1 root root  68K Aug 18 08:10 icinga2-common_2.16.5-1+ubuntu22.04_all.deb
-rw-r--r-- 1 root root 128K Aug 18 08:10 icinga2_2.16.5-1+ubuntu22.04_amd64.deb

cd /root/debs
apt-get install -y ./icinga2_2.16.5-1+ubuntu22.04_amd64.deb ./icinga2-bin_2.16.5-1+ubuntu22.04_amd64.deb ./icinga2-common_2.16.5-1+ubuntu22.04_all.deb

0 upgraded, 23 newly installed, 0 to remove and 2 not upgraded.
Setting up icinga2-common (2.16.5-1+ubuntu22.04) ...
Setting up icinga2-bin (2.16.5-1+ubuntu22.04) ...
Setting up icinga2 (2.16.5-1+ubuntu22.04) ...

icinga2 --version | head -1

icinga2 - The Icinga 2 network monitoring daemon (version: r2.16.5-1)

export DEBIAN_FRONTEND=noninteractive
apt-get install -y icingaweb2 icingacli
icingacli --version

Icinga Web 2  2.12.7
Git Commit    36bafad37c6edc138b0353d6ade2f1b99704454d
PHP Version   8.1.2-1ubuntu2.27
MODULE  VERSION
setup  2.12.7

systemctl start apache2
systemctl is-active apache2

active

mariadb -e "CREATE DATABASE IF NOT EXISTS icingaweb CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci; GRANT ALL PRIVILEGES ON icingaweb.* TO 'icingaweb'@'localhost' IDENTIFIED BY 'q1w2e3r4'; FLUSH PRIVILEGES;"
mariadb -e "SHOW DATABASES;"

Database
icinga2
icingaweb
information_schema
mysql
performance_schema
sys

icingacli setup token create

The newly generated setup token is: ca66327a1c2e5a45

ls /etc/icingaweb2/
ls /etc/icingaweb2/enabledModules/
icingacli module list

authentication.ini
config.ini
enabledModules
groups.ini
modules
resources.ini
roles.ini
monitoring
MODULE         VERSION   STATE     DESCRIPTION
monitoring     2.12.6    enabled   Icinga monitoring module

icingacli monitoring list hosts

   UP    icinga1.example.com: PING OK - Packet loss = 0%, RTA = 0.03 ms

object Host "web1.example.com" {
  import "generic-host"
  address = "192.168.1.100"
  check_command = "hostalive"
}

   icinga2 | 2.16.5-1+ubuntu22.04 | https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
   icinga2 | 2.16.4-1+ubuntu22.04 | https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
   icinga2 | 2.16.3-1+ubuntu22.04 | https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages
   icinga2 | 2.16.2-1+ubuntu22.04 | https://packages.icinga.com/ubuntu icinga-jammy/main amd64 Packages

SELECT o.name1 AS host, hs.current_state, hs.output
FROM icinga_hoststatus hs
JOIN icinga_objects o ON o.object_id = hs.host_object_id AND o.objecttype_id = 1;

systemctl stop icinga2 apache2
apt-get purge -y icinga2 icinga2-ido-mysql icingaweb2 icingacli
apt-get autoremove -y
mariadb -e "DROP DATABASE IF EXISTS icinga2; DROP DATABASE IF EXISTS icingaweb; DROP USER IF EXISTS 'icinga2'@'localhost'; DROP USER IF EXISTS 'icingaweb'@'localhost'; FLUSH PRIVILEGES;"
rm -f /etc/apt/sources.list.d/icinga.list /usr/share/keyrings/icinga-archive-keyring.gpg
rm -rf /var/lib/icinga2 /var/log/icinga2 /var/cache/icinga2