can download from the [Icinga website](https://www.icinga.org/). The
release tarballs contain an `INSTALL` file with further instructions.
+### <a id="installation-enabled-features"></a> Enabled Features during Installation
+
+The default installation will enable three features required for a basic
+Icinga 2 installation:
+
+* `checker` for executing checks
+* `notification` for sending notifications
+* `mainlog` for writing the `icinga2.log ` file
+
+Verify that by calling `icinga2-enable-feature` withour any additional parameters
+and enable the missing features, if any.
+
+ # icinga2-enable-feature
+ Syntax: /usr/sbin/icinga2-enable-feature <features separated with whitespaces>
+ Example: /usr/sbin/icinga2-enable-feature checker notification mainlog
+ Enables the specified feature(s).
+
+ Available features: api checker command compatlog debuglog graphite icingastatus ido-mysql ido-pgsql livestatus mainlog notification perfdata statusdata syslog
+ Enabled features: checker mainlog notification
### <a id="installation-paths"></a> Installation Paths
Details on troubleshooting notification problems can be found [here](#troubleshooting).
+> **Note**
+>
+> Make sure that the [notification](#features) feature is enabled on your master instance
+> in order to execute notification commands.
+
You should choose which information you (and your notified users) are interested in
case of emergency, and also which information does not provide any value to you and
your environment.
`CheckCommand` objects define the command line how a check is called.
+> **Note**
+>
+> Make sure that the [checker](#features) feature is enabled in order to
+> execute checks.
+
#### <a id="command-plugin-integration"></a> Integrate the Plugin with a CheckCommand Definition
`CheckCommand` objects require the [ITL template](#itl-plugin-check-command)
`NotificationCommand` objects require the [ITL template](#itl-plugin-notification-command)
`plugin-notification-command` to support native plugin-based notifications.
+> **Note**
+>
+> Make sure that the [notification](#features) feature is enabled on your master instance
+> in order to execute notification commands.
+
Below is an example using runtime macros from Icinga 2 (such as `$service.output$` for
the current check output) sending an email to the user(s) associated with the
notification itself (`$user.email$`).
# sudo -u icinga /usr/lib/nagios/plugins/check_ping -4 -H 127.0.0.1 -c 5000,100% -w 3000,80%
+* Make sure the [checker](#features) feature is enabled.
+
+ # icinga2-enable-feature checker
+ Total params: 1
+ The feature 'checker' is already enabled.
+
+
## <a id="notifications-not-sent"></a> Notifications are not sent
* Check the debug log if a notification is triggered
* Do the user attributes `states`, `types`, `period` match the notification conditions?
* Are there any notification `begin` and `end` times configured?
+* Make sure the [notification](#features) feature is enabled.
+
+ # icinga2-enable-feature notification
+ Total params: 1
+ The feature 'notification' is already enabled.
+
* Does the referenced NotificationCommand work executed as Icinga user on the shell?
## <a id="feature-not-working"></a> Feature is not working