[metricbeat] add doc for priorityClassName

metricbeat/README.md

@@ -71,7 +71,7 @@ helm install --name metricbeat elastic/metricbeat --set imageTag=7.5.1
 | `extraEnvs`              | Extra [environment variables](https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/#using-environment-variables-inside-of-your-config) which will be appended to the `env:` definition for the container                          | `[]`                                                                                                                      |
 | `extraVolumeMounts`      | Templatable string of additional volumeMounts to be passed to the `tpl` function                                                                                                                                                                                            | `""`                                                                                                                      |
 | `extraVolumes`           | Templatable string of additional volumes to be passed to the `tpl` function                                                                                                                                                                                                 | `""`                                                                                                                      |
-| `envFrom`              | Templatable string of envFrom to be passed to the  [environment from variables](https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/#configure-all-key-value-pairs-in-a-configmap-as-container-environment-variables) which will be appended to the `envFrom:` definition for the container                          | `[]`                            
+| `envFrom`              | Templatable string of envFrom to be passed to the  [environment from variables](https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/#configure-all-key-value-pairs-in-a-configmap-as-container-environment-variables) which will be appended to the `envFrom:` definition for the container                          | `[]`
 | `hostPathRoot`           | Fully-qualified [hostPath](https://kubernetes.io/docs/concepts/storage/volumes/#hostpath) that will be used to persist Metricbeat registry data                                                                                                                             | `/var/lib`                                                                                                                |
 | `image`                  | The Metricbeat docker image                                                                                                                                                                                                                                                 | `docker.elastic.co/beats/metricbeat`                                                                                      |
 | `imageTag`               | The Metricbeat docker image tag                                                                                                                                                                                                                                             | `7.5.1`                                                                                                                   |
@@ -92,6 +92,7 @@ helm install --name metricbeat elastic/metricbeat --set imageTag=7.5.1
 | `nodeSelector`           | Configurable [nodeSelector](https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#nodeselector)                                                                                                                                                                | `{}`                                                                                                                      |
 | `affinity`               | Configurable [affinity](https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#affinity-and-anti-affinity)                                                                                                                                                      | `{}`                                                                                                                      |
 | `updateStrategy`         | The [updateStrategy](https://kubernetes.io/docs/tasks/manage-daemon/update-daemon-set/#daemonset-update-strategy) for the `DaemonSet`. By default Kubernetes will kill and recreate pods on updates. Setting this to `OnDelete` will require that pods be deleted manually. | `RollingUpdate`                                                                                                           |
+| `priorityClassName`      | The [name of the PriorityClass](https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/#priorityclass). No default is supplied as the PriorityClass must be created first.                                                                               | `""`                                                                                                                      |
 | `replicas`               | The replica count for the metricbeat deployment talking to kube-state-metrics                                                                                                                                                                                               | `1`                                                                                                                       |
 | `fullnameOverride`       | Overrides the full name of the resources. If not set the name will default to "`.Release.Name`-`.Values.nameOverride or .Chart.Name`"                                                                                                                                       | `""`                                                                                                                      |