OSDOCS-14472: CPMS custom machine name prefixes

Author: skopacz1

machine_management/control_plane_machine_management/cpmso-configuration.adoc

@@ -17,6 +17,14 @@ include::modules/cpmso-yaml-sample-cr.adoc[leveloffset=+1]
 
 * xref:../../machine_management/control_plane_machine_management/cpmso-managing-machines.adoc#cpmso-feat-config-update_cpmso-managing-machines[Updating the control plane configuration]
 
+[id="cpmso-config-options_{context}"]
+== Control plane machine set configuration options
+
+You can configure your control plane machine set to make customizations that meet your cluster's needs.
+
+//Adding a custom prefix to control plane machine names
+include::modules/cpmso-config-options.adoc[leveloffset=+2]
+
 [id="cpmso-sample-yaml-provider-specific_{context}"]
 == Provider-specific configuration options
 

modules/cpmso-config-options.adoc

@@ -0,0 +1,40 @@
+// Module included in the following assemblies:
+//
+// * machine_management/cpmso-configuration.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="cpmso-config-prefix_{context}"]
+= Adding a custom prefix to control plane machine names
+
+You can customize the prefix of machine names created by a control plane machine set.
+This can be done by editing a control plane machine set custom resource (CR)
+
+.Procedure
+
+// Saw the step below in another procedure, let me know if it's good to keep it in here.
+
+. Edit your control plane machine set CR by running the following command:
++
+[source,terminal]
+----
+$ oc edit controlplanemachineset.machine.openshift.io cluster \
+  -n openshift-machine-api
+----
+
+. Add the following snippet to the `ControlPlaneMachineSet` CR:
++
+[source,yaml]
+----
+spec:
+  machineNamePrefix: <machine_prefix>
+----
++
+where `<machine_prefix>` specifies a prefix name that satisfies the following requirements:
+
+** The name contains no more than 253 characters
+** The name contains only lowercase alphanumeric characters, `-`, or `.`
+** The name starts and ends with an alphanumeric character
+
+. Save your changes to the `ControlPlaneMachineSet` CR.
+
+. If you are using an `OnDelete` update strategy for your control plane machine set: Manually apply the prefix to the name of any existing machines.