Docs: Refine Metric Sync

README.md

@@ -45,6 +45,15 @@ We welcome your ideas on what should be included in the baseline.
 Do not hesitate to share your key metrics, important thresholds,
 or correlations used to set up alarms in your environments.
 
+## Optional Features
+
+### Metric Sync
+
+Icinga for Kubernetes integrates with Prometheus to synchronize predefined metrics and display charts in the UI.
+In future versions, we plan to incorporate these metrics into state evaluation and alerting.
+To enable this feature you just have to configure a Prometheus server URL
+that collects metrics from your Kubernetes cluster.
+
 ## Documentation
 
 Icinga for Kubernetes documentation is available at [icinga.com/docs](https://icinga.com/docs/icinga-kubernetes).

doc/01-About.md

@@ -18,6 +18,15 @@ At the moment it is only possible to monitor one Kubernetes cluster per Icinga f
 ![Icinga for Kubernetes Web Service](res/icinga-kubernetes-web-service.png)
 ![Icinga for Kubernetes Web Pod](res/icinga-kubernetes-web-pod.png)
 
+## Optional Features
+
+### Metric Sync
+
+Icinga for Kubernetes integrates with Prometheus to synchronize predefined metrics and display charts in the UI.
+In future versions, we plan to incorporate these metrics into state evaluation and alerting.
+To enable this feature you have to [configure a Prometheus server URL](03-Configuration.md#prometheus-configuration)
+that collects metrics from your Kubernetes cluster.
+
 ## Installation
 
 To install Icinga for Kubernetes see [Installation](02-Installation.md).

doc/03-Configuration.md

@@ -25,11 +25,10 @@ This is also the database used in
 
 ## Prometheus Configuration
 
-Icinga for Kubernetes can synchronize metrics from Prometheus using the Prometheus API.
-The configuration for Prometheus is stored in the `prometheus` section of the [config.example.yml](../config.example.yml) file.
+Connection configuration for a Prometheus instance that collects metrics from your Kubernetes cluster,
+from which Icinga for Kubernetes [synchronizes predefined metrics](01-About.md#metric-sync) to display charts in the UI.
+Defined in the `prometheus` section of the configuration file.
 
-| Option | Description                                                       |
-|--------|-------------------------------------------------------------------|
-| url    | **Required.** The URL (`[Host]:[Port]`) of the Prometheus server. |
-
-Ensure that the URL points to a running Prometheus instance that collects metrics from your Kubernetes cluster.
+| Option | Description                                                                          |
+|--------|--------------------------------------------------------------------------------------|
+| url    | **Optional.** Prometheus server URL. If not set, metric synchronization is disabled. |