<!-- {% if index %} -->
# Installation <a id="installation"></a>

This tutorial is a step-by-step introduction to install Icinga 2.
It assumes that you are familiar with the operating system you're using to install Icinga 2.

Please follow the steps listed for your operating system. Packages for distributions other than the ones
listed here may also be available. Please refer to [icinga.com/get-started/download](https://icinga.com/get-started/download/#community)
for a full list of available community repositories.

## Upgrade <a id="upgrade"></a>

In case you are upgrading an existing setup, please ensure to
follow the [upgrade documentation](16-upgrading-icinga-2.md#upgrading-icinga-2).
<!-- {% else %} -->

<!-- {% if not windows %} -->
## Add Icinga Package Repository <a id="add-icinga-package-repository"></a>

We recommend using our official repositories.

All the following commands should be executed as the root user.
As pipes and nested commands are used, it is recommended to switch to a root user session, e.g., using `sudo -i`.

Here's how to add it to your system:
<!-- {% endif %} -->

<!-- {% if debian %} -->

### Debian Repository <a id="debian-repository"></a>

```bash
apt update
apt -y install apt-transport-https wget

wget -O icinga-archive-keyring.deb "https://packages.icinga.com/icinga-archive-keyring_latest+debian$(
 . /etc/os-release; echo "$VERSION_ID"
).deb"

apt install ./icinga-archive-keyring.deb

DIST=$(awk -F"[)(]+" '/VERSION=/ {print $2}' /etc/os-release); \
 echo "deb [signed-by=/usr/share/keyrings/icinga-archive-keyring.gpg] https://packages.icinga.com/debian icinga-${DIST} main" > \
 /etc/apt/sources.list.d/${DIST}-icinga.list
 echo "deb-src [signed-by=/usr/share/keyrings/icinga-archive-keyring.gpg] https://packages.icinga.com/debian icinga-${DIST} main" >> \
 /etc/apt/sources.list.d/${DIST}-icinga.list

apt update
```
<!-- {% endif %} -->

<!-- {% if ubuntu %} -->
### Ubuntu Repository <a id="ubuntu-repository"></a>

```bash
apt update
apt -y install apt-transport-https wget

wget -O icinga-archive-keyring.deb "https://packages.icinga.com/icinga-archive-keyring_latest+ubuntu$(
 . /etc/os-release; echo "$VERSION_ID"
).deb"

apt install ./icinga-archive-keyring.deb

. /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/${DIST}-icinga.list
 echo "deb-src [signed-by=/usr/share/keyrings/icinga-archive-keyring.gpg] https://packages.icinga.com/ubuntu icinga-${DIST} main" >> \
 /etc/apt/sources.list.d/${DIST}-icinga.list

apt update
```
<!-- {% endif %} -->

<!-- {% if rhel %} -->
### RHEL Repository <a id="rhel-repository"></a>

!!! info

    A paid repository subscription is required for RHEL repositories. Get more information on
    [icinga.com/subscription](https://icinga.com/subscription)

    Don't forget to fill in the username and password section with your credentials in the local .repo file.

```bash
wget https://packages.icinga.com/subscription/rhel/ICINGA-release.repo -O /etc/yum.repos.d/ICINGA-release.repo
```

If you are using RHEL you need to additionally enable the `codeready-builder`
repository before installing the [EPEL rpm package](https://fedoraproject.org/wiki/EPEL#How_can_I_use_these_extra_packages.3F).

#### RHEL 8 or Later

```bash
ARCH=$(/bin/arch)
OSVER=$(. /etc/os-release; echo "${VERSION_ID%%.*}")

subscription-manager repos --enable "codeready-builder-for-rhel-${OSVER}-${ARCH}-rpms"

dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-${OSVER}.noarch.rpm
```

<!-- {% endif %} -->

<!-- {% if fedora %} -->
### Fedora Repository <a id="fedora-repository"></a>

```bash
rpm --import https://packages.icinga.com/icinga.key
curl -o /etc/yum.repos.d/ICINGA-release.repo https://packages.icinga.com/fedora/ICINGA-release.repo
```

<!-- {% endif %} -->

<!-- {% if sles %} -->
### SLES Repository <a id="sles-repository"></a>

!!! info

    A paid repository subscription is required for SLES repositories. Get more information on
    [icinga.com/subscription](https://icinga.com/subscription)

    Don't forget to fill in the username and password section with your credentials in the local .repo file.

```bash
zypper ar https://packages.icinga.com/subscription/sles/ICINGA-release.repo
zypper ref
```

You need to additionally add the `PackageHub` repository to fulfill dependencies:

```bash
source /etc/os-release

SUSEConnect -p PackageHub/$VERSION_ID/x86_64
```
<!-- {% endif %} -->

<!-- {% if opensuse %} -->
### openSUSE Repository <a id="opensuse-repository"></a>

```bash
zypper ar https://packages.icinga.com/openSUSE/ICINGA-release.repo
zypper ref
```
<!-- {% endif %} -->

<!-- {% if amazon_linux %} -->
### Amazon Linux Repository <a id="amazon-linux-2-repository"></a>

!!! info

    A paid repository subscription is required for Amazon Linux repositories. Get more information on
    [icinga.com/subscription](https://icinga.com/subscription)

    Don't forget to fill in the username and password section with your credentials in the local .repo file.

```bash
wget https://packages.icinga.com/subscription/amazon/ICINGA-release.repo -O /etc/yum.repos.d/ICINGA-release.repo
```
<!-- {% endif %} -->

<!-- {% if windows %} -->
### Icinga for Windows Repository <a id="icinga-for-windows-repository"></a>
[Icinga for Windows](https://icinga.com/docs/icinga-for-windows/latest/doc/000-Introduction/) is the recommended
way to install and update Icinga 2 on Windows.

We provide a dedicated repository for Windows to simplify the installation. Please refer to the official
[Icinga for Windows installation docs](https://icinga.com/docs/icinga-for-windows/latest/doc/110-Installation/01-Getting-Started/)
<!-- {% else %} -->

## Install Icinga 2 <a id="installing-icinga2"></a>

You can install Icinga 2 by using your distribution's package manager
to install the `icinga2` package. The following commands must be executed
with `root` permissions unless noted otherwise.

<!-- {% if rhel or fedora or amazon_linux %} -->
!!! tip

    If you have [SELinux](22-selinux.md) enabled, the package `icinga2-selinux` is also required.
<!-- {% endif %} -->

<!-- {% if debian or ubuntu %} -->
<!-- {% if not icingaDocs %} -->
#### Debian / Ubuntu / Raspberry Pi OS
<!-- {% endif %} -->
```bash
apt install icinga2
```
<!-- {% endif %} -->

<!-- {% if rhel %} -->
#### RHEL 8 or Later

```bash
dnf install icinga2
systemctl enable icinga2
systemctl start icinga2
```
<!-- {% endif %} -->

<!-- {% if fedora %} -->
<!-- {% if not icingaDocs %} -->
#### Fedora
<!-- {% endif %} -->
```bash
dnf install icinga2
systemctl enable icinga2
systemctl start icinga2
```
<!-- {% endif %} -->

<!-- {% if sles or opensuse %} -->
<!-- {% if not icingaDocs %} -->
#### SLES / openSUSE
<!-- {% endif %} -->
```bash
zypper install icinga2
```
<!-- {% endif %} -->

<!-- {% if amazon_linux %} -->
<!-- {% if not icingaDocs %} -->
#### Amazon Linux
<!-- {% endif %} -->
```bash
yum install icinga2
systemctl enable icinga2
systemctl start icinga2
```
<!-- {% endif %} -->

### Systemd Service <a id="systemd-service"></a>

The majority of supported distributions use systemd. The Icinga 2 packages automatically install the necessary
systemd unit files.

If you're stuck with configuration errors, you can manually invoke the
[configuration validation](11-cli-commands.md#config-validation).

```bash
icinga2 daemon -C
```

!!! tip

    If you are running into fork errors with systemd enabled distributions,
    please check the [troubleshooting chapter](15-troubleshooting.md#check-fork-errors).


## Set up Check Plugins <a id="setting-up-check-plugins"></a>

Without plugins Icinga 2 does not know how to check external services. The
[Monitoring Plugins Project](https://www.monitoring-plugins.org/) provides
an extensive set of plugins which can be used with Icinga 2 to check whether
services are working properly.

These plugins are required to make the [example configuration](04-configuration.md#configuring-icinga2-overview)
work out-of-the-box.

Depending on which directory your plugins are installed into you may need to
update the global `PluginDir` constant in your [Icinga 2 configuration](04-configuration.md#constants-conf).
This constant is used by the check command definitions contained in the Icinga Template Library
to determine where to find the plugin binaries.

!!! tip

    Please refer to the [service monitoring](05-service-monitoring.md#service-monitoring-plugins) chapter for details about how to integrate
    additional check plugins into your Icinga 2 setup.


<!-- {% if debian or ubuntu %} -->
<!-- {% if not icingaDocs %} -->
#### Debian / Ubuntu / Raspberry Pi OS
<!-- {% endif %} -->
```bash
apt install monitoring-plugins
```
<!-- {% endif %} -->

<!-- {% if rhel %} -->
<!-- {% if not icingaDocs %} -->
#### RHEL
<!-- {% endif %} -->
The packages for RHEL depend on other packages which are distributed as part of the EPEL repository.

#### RHEL 8 or Later

```bash
dnf install nagios-plugins-all
```
<!-- {% endif %} -->

<!-- {% if fedora %} -->
<!-- {% if not icingaDocs %} -->
#### Fedora
<!-- {% endif %} -->
```bash
dnf install nagios-plugins-all
```
<!-- {% endif %} -->

<!-- {% if sles or opensuse %} -->
<!-- {% if not icingaDocs %} -->
#### SLES / openSUSE
<!-- {% endif %} -->
The packages depend on other packages which are distributed
as part of the [server:monitoring repository](https://build.opensuse.org/project/repositories/server:monitoring).
Please make sure to enable this repository beforehand.

```bash
zypper install --recommends monitoring-plugins-all
```
<!-- {% endif %} -->

<!-- {% if amazon_linux %} -->
<!-- {% if not icingaDocs %} -->
#### Amazon Linux
<!-- {% endif %} -->
Unfortunately newer versions of Amazon Linux don't provide those plugins, yet.
<!-- {% endif %} -->

## Set up Icinga 2 API <a id="set-up-icinga2-api"></a>

Almost every Icinga 2 setup requires the Icinga 2 API as Icinga Web connects to it, Icinga DB requires it,
and it enables cluster communication functionality for highly available and distributed setups.

!!! info

    If you set up a highly available and/or distributed Icinga monitoring environment, please read the
    [Distributed Monitoring](06-distributed-monitoring.md#distributed-monitoring) chapter as
    the commands to set up the API are different from setting up a single node setup.

See the [API](12-icinga2-api.md#icinga2-api-setup) chapter for details,
or follow the steps below to set up the API quickly:

Run the following command to:

* enable the `api` feature,
* set up certificates, and
* add the API user `root` with an auto-generated password in the configuration file
  `/etc/icinga2/conf.d/api-users.conf`.

```bash
icinga2 api setup
```

For new installations, it is recommended to set the following additional attribute inside the `ApiListener` object
definition in `/etc/icinga2/features-enabled/api.conf`. This will already enforce stricter permissions as they will
become the default with v2.17 (see the [upgrading documentation](16-upgrading-icinga-2.md#upgrading-to-2-16-2) for the
version that introduced that setting for more details):

```
enforce_filter_expression_permission = true
```

Restart Icinga 2 for these changes to take effect.

```bash
systemctl restart icinga2
```

## Set up Icinga DB <a id="set-up-icinga-db"></a>

Icinga DB is a set of components for publishing, synchronizing and
visualizing monitoring data in the Icinga ecosystem, consisting of:

* Icinga 2 with its `icingadb` feature enabled,
  responsible for publishing monitoring data to a Redis server, i.e. configuration and its runtime updates,
  check results, state changes, downtimes, acknowledgements, notifications, and other events such as flapping
* The [Icinga DB daemon](https://icinga.com/docs/icinga-db),
  which synchronizes the data between the Redis server and a database
* And Icinga Web with the
  [Icinga DB Web](https://icinga.com/docs/icinga-db-web) module enabled,
  which connects to both Redis and the database to display and work with the most up-to-date data

![Icinga DB Architecture](images/icingadb/icingadb-architecture.png)

!!! info

    Setting up Icinga 2's Icinga DB feature is only required for Icinga 2 master nodes or single-node setups.

### Set up Redis Server <a id="set-up-redis-server"></a>

A Redis server from version 6.2 is required.

!!! info

    This guide sets up the `icingadb-redis` package provided by Icinga,
    which ships a current Redis Server version and is preconfigured for the Icinga DB components.
    Using own Redis server setups is supported as long as the version requirements are met.

![Icinga DB Redis](images/icingadb/icingadb-redis.png)

!!! tip

    Although the Redis server can run anywhere in an Icinga environment,
    we recommend to install it where the corresponding Icinga 2 node is running to
    keep latency between the components low.

#### Install Icinga DB Redis Package <a id="install-icinga-db-redis-package"></a>

Use your distribution's package manager to install the `icingadb-redis` package.

<!-- {% if amazon_linux or fedora or rhel or opensuse or sles %} -->
!!! tip

    If you have [SELinux](22-selinux.md) enabled, the package `icingadb-redis-selinux` is also required.
<!-- {% endif %} -->

<!-- {% if amazon_linux %} -->
<!-- {% if not icingaDocs %} -->
##### Amazon Linux
<!-- {% endif %} -->
```bash
yum install icingadb-redis
```
<!-- {% endif %} -->

<!-- {% if debian or ubuntu %} -->
<!-- {% if not icingaDocs %} -->
##### Debian / Ubuntu / Raspberry Pi OS
<!-- {% endif %} -->
```bash
apt install icingadb-redis
```
<!-- {% endif %} -->

<!-- {% if rhel %} -->
##### RHEL 8 or Later

```bash
dnf install icingadb-redis
```
<!-- {% endif %} -->

<!-- {% if fedora %} -->
<!-- {% if not icingaDocs %} -->
##### Fedora
<!-- {% endif %} -->
```bash
dnf install icingadb-redis
```
<!-- {% endif %} -->

<!-- {% if sles or opensuse %} -->
<!-- {% if not icingaDocs %} -->
##### SLES / openSUSE
<!-- {% endif %} -->
```bash
zypper install icingadb-redis
```
<!-- {% endif %} -->

#### Run Icinga DB Redis <a id="run-icinga-db-redis"></a>

The `icingadb-redis` package automatically installs the necessary systemd unit files to run Icinga DB Redis.
Please run the following command to enable and start its service:

```bash
systemctl enable --now icingadb-redis
```

#### Enable Remote Redis Connections <a id="enable-remote-redis-connections"></a>

By default, `icingadb-redis` only listens on `127.0.0.1`. If Icinga Web or Icinga 2 is running on another node,
remote access to the Redis server must be allowed. This requires the following directives to be set in
the `/etc/icingadb-redis/icingadb-redis.conf` configuration file:

* Set `protected-mode` to `no`, i.e. `protected-mode no`
* Set `bind` to the desired binding interface or bind all interfaces, e.g. `bind 0.0.0.0`

!!! warning

    By default, Redis has no authentication preventing others from accessing it.
    When opening Redis to an external interface, make sure to set a password, set up appropriate firewall rules,
    or configure TLS with certificate authentication on Redis and its consumers,
    i.e. Icinga 2, Icinga DB and Icinga Web.

Restart Icinga DB Redis for these changes to take effect:

```bash
systemctl restart icingadb-redis
```

### Enable Icinga DB Feature <a id="enable-icinga-db-feature"></a>

With the [Icinga DB feature](14-features.md#icinga-db) enabled,
Icinga 2 publishes all of its monitoring data to the Redis server. This includes configuration and
its runtime updates via the Icinga 2 API, check results, state changes, downtimes, acknowledgments, notifications and
other events such as flapping.

![Icinga DB Icinga 2](images/icingadb/icingadb-icinga2.png)

Icinga 2 installs the feature configuration file to `/etc/icinga2/features-available/icingadb.conf`,
pre-configured for a local setup.
Update this file in case Redis is running on a different host or to set credentials.
All available settings are explained in the [Icinga DB object](09-object-types.md#icingadb) chapter.

!!! important

    For single-node and high-availability setups, please read the note about the
    [environment ID](https://icinga.com/docs/icinga-db/latest/doc/05-Distributed-Setups/#environment-id),
    which is common to all Icinga DB components and generated by the Icinga DB feature.

To enable the `icingadb` feature use the following command:

```bash
icinga2 feature enable icingadb
```

Restart Icinga 2 for these changes to take effect:

```bash
systemctl restart icinga2
```

### Install Icinga DB Daemon <a id="install-icinga-db-daemon"></a>

After installing Icinga 2, setting up a Redis server and enabling the `icingadb` feature,
the Icinga DB daemon that synchronizes monitoring data between the Redis server and a database is now set up.

![Icinga DB Daemon](images/icingadb/icingadb-daemon.png)

!!! tip

    Although the Icinga DB daemon can run anywhere in an Icinga environment,
    we recommend to install it where the corresponding Icinga 2 node and Redis server is running to
    keep latency between the components low.

The Icinga DB daemon package is also included in the Icinga repository, and since it is already set up,
you have completed the instructions here and can proceed to
<!-- {% if amazon_linux %} -->
[install the Icinga DB daemon on Amazon Linux](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/Amazon-Linux/#installing-the-package),
<!-- {% endif %} -->
<!-- {% if debian %} -->
[install the Icinga DB daemon on Debian](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/Debian/#installing-the-package),
<!-- {% endif %} -->
<!-- {% if fedora %} -->
[install the Icinga DB daemon on Fedora](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/Fedora/#installing-the-package),
<!-- {% endif %} -->
<!-- {% if rhel %} -->
[install the Icinga DB daemon on RHEL](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/RHEL/#installing-the-package),
<!-- {% endif %} -->
<!-- {% if sles %} -->
[install the Icinga DB daemon on SLES](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/SLES/#installing-the-package),
<!-- {% endif %} -->
<!-- {% if ubuntu %} -->
[install the Icinga DB daemon on Ubuntu](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/Ubuntu/#installing-the-package),
<!-- {% endif %} -->
<!-- {% if opensuse %} -->
[install the Icinga DB daemon on openSUSE](https://icinga.com/docs/icinga-db/latest/doc/02-Installation/openSUSE/#installing-the-package),
<!-- {% endif %} -->
which will also guide you through the setup of the database and Icinga DB Web.

## Backup <a id="install-backup"></a>

Ensure to include the following in your backups:

* Configuration files in `/etc/icinga2`
* Certificate files in `/var/lib/icinga2/ca` (Master CA key pair) and `/var/lib/icinga2/certs` (node certificates)
* Runtime files in `/var/lib/icinga2`
<!-- {% endif %} --><!-- {# end windows else #} -->
<!-- {% endif %} --><!-- {# end index else #} -->
