remove auto-dectection explanation

Author: maltesander

modules/guides/pages/kubernetes-cluster-domain.adoc

@@ -3,45 +3,13 @@
 :dns-custom-nameservers: https://kubernetes.io/docs/tasks/administer-cluster/dns-custom-nameservers/
 :dns-pod-service: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/
 
-Stackable operators allow to configure a non-default cluster domain as described in {dns-custom-nameservers}[Customizing DNS Service] (and more in {dns-pod-service}[DNS for Services and Pods]).
-The configuration is primarily done via an environment variable `KUBERNETES_CLUSTER_DOMAIN`, but there is also a mechanism to auto detect the cluster domain using the `/etc/resolv.conf` file.
+Stackable operators allow the configuration of a non-default cluster domain as described in {dns-custom-nameservers}[Customizing DNS Service] (and more in {dns-pod-service}[DNS for Services and Pods]).
 
-The following steps explain the use of the environment variable and the auto detection mechanism in detail:
-
-== Steps
-
-=== Use environment variable
-
-The environment variable `KUBERNETES_CLUSTER_DOMAIN` takes precedence over auto detection.
-This means that the desired cluster domain can be configured in a Helm values file via the property `kubernetesClusterDomain` or via the install command like:
+The cluster domain can be configured using an environment variable `KUBERNETES_CLUSTER_DOMAIN` set on the operators.
+This environment variable can be configured via the helm values property `kubernetesClusterDomain` during the installation of the operators.
 
 ```
-helm install hive-operator stackable-stable/hive-operator --set kubernetesClusterDomain="my-cluster.local"
+helm install <product>-operator stackable-stable/<product>-operator --set kubernetesClusterDomain="my-cluster.local"
 ```
 
-=== Use auto detection
-
-If the `KUBERNETES_CLUSTER_DOMAIN` environment variable is not set, the auto detection is checking the runtime environment of the operator.
-In most cases this is a clusterized environment like Kubernetes or Openshift.
-This is determined by checking if the `KUBERNETES_SERVICE_HOST` environment variable is set in the operator Pod.
-
-If clusterized, the auto detection parses the `/etc/resolv.conf` file for the last entry starting with the `search` keyword.
-Within that `search` entry the shortest option is selected.
-
-An example `/etc/resolv.conf` in a Pod looks like:
-
-```
-nameserver 10.32.0.10
-search <namespace>.svc.cluster.local svc.cluster.local cluster.local
-options ndots:5
-```
-
-Using this example as a base for the cluster domain auto detection, the operator would choose `cluster.local` as cluster domain.
-
-=== Running locally
-
-This section covers the case when both `KUBERNETES_CLUSTER_DOMAIN` and `KUBERNETES_SERVICE_HOST` are not set.
-This would be the case if the operator is not running in a clusterized environment like e.g. locally a Laptop or PC.
-Running the operator locally is mostly for development and therefore not relevant for most users.
-
-If running locally, and `KUBERNETES_CLUSTER_DOMAIN` and `KUBERNETES_SERVICE_HOST` are not set, the operator will default its cluster domain to `cluster.local`.
+If the environment variable `KUBERNETES_CLUSTER_DOMAIN` (or the helm property `kubernetesClusterDomain`) are not set / overriden, the operator will default its cluster domain to `cluster.local`.