diff --git a/modules/guides/pages/kubernetes-cluster-domain.adoc b/modules/guides/pages/kubernetes-cluster-domain.adoc index d435ea10f..9487557c6 100644 --- a/modules/guides/pages/kubernetes-cluster-domain.adoc +++ b/modules/guides/pages/kubernetes-cluster-domain.adoc @@ -21,12 +21,14 @@ helm install hive-operator stackable-stable/hive-operator --set kubernetesCluste === Use auto detection -As a first step, the auto detection is checking the runtime environment of the operator. In most cases this is a clusterized environment like Kubernetes or Openshift. +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. +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 for the `/etc/resolv.conf` in a Kubelet looks like: +An example `/etc/resolv.conf` in a Pod looks like: ``` nameserver 10.32.0.10 @@ -34,11 +36,12 @@ search .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 the `cluster.local` option. +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 on a Laptop or PC. +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`.