Merge pull request #104197 from openshift-cherrypick-robot/cherry-pick-104190-to-enterprise-4.21

[enterprise-4.21] Added a section for day2 operator for azure disk encryption sets.

Author: mburke5678

installing/installing_azure/ipi/installing-azure-preparing-ipi.adoc

@@ -36,6 +36,8 @@ include::modules/cluster-telemetry.adoc[leveloffset=+1]
 
 * For more information about the Telemetry service, see xref:../../../support/remote_health_monitoring/about-remote-health-monitoring.adoc#about-remote-health-monitoring[About remote health monitoring]
 
+include::modules/installation-azure-day2-operations-diskencryptionsets.adoc[leveloffset=+1]
+
 include::modules/installation-azure-preparing-diskencryptionsets.adoc[leveloffset=+1]
 
 .Next steps
@@ -44,4 +46,4 @@ include::modules/installation-azure-preparing-diskencryptionsets.adoc[leveloffse
 ** xref:../../../installing/installing_azure/ipi/installing-azure-customizations.adoc#installing-azure-customizations[Install a cluster with customizations on installer-provisioned infrastructure]
 ** xref:../../../installing/installing_azure/ipi/installing-azure-vnet.adoc#installing-azure-vnet[Install a cluster into an existing VNet on installer-provisioned infrastructure]
 ** xref:../../../installing/installing_azure/ipi/installing-azure-private.adoc#installing-azure-private[Install a private cluster on installer-provisioned infrastructure]
-** xref:../../../installing/installing_azure/ipi/installing-azure-government-region.adoc#installing-azure-government-region[Install a cluster into an government region on installer-provisioned infrastructure]
+** xref:../../../installing/installing_azure/ipi/installing-azure-government-region.adoc#installing-azure-government-region[Install a cluster into an government region on installer-provisioned infrastructure]

modules/installation-azure-day2-operations-diskencryptionsets.adoc

@@ -0,0 +1,80 @@
+// Module included in the following assemblies:
+//
+// * installing/installing_azure/enabling-disk-encryption-sets-azure.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="installation-azure-day2-operations-diskencryptionsets.adoc_{context}"]
+= Preparing an Azure Disk Encryption Set for Day2 Operator
+
+The {product-title} installation program can use an existing Disk Encryption Set with a user-managed key. To enable this feature, create a `DiskEncryptionSet` object in Azure and provide the key to the installation program. 
+
+.Prerequisite
+
+* You enabled the `EncryptionAtHost` feature in your {azure-short} subscription. For more information, see "Use the Azure portal to enable end-to-end encryption using encryption at host".
+.Procedure
+
+. Mark the node from the `encyptionAtHost` cluster resource group as unschedulable by using the following command:
++
+[source,terminal]
+----
+$ oc adm cordon <node_name>
+----
+
+. Evacuate the pods from the compute node. There are several ways to do this. For example, you can evacuate all the pods or the selected pods on a node: 
++
+[source,terminal]
+----
+$ oc adm drain <compute_node> [--pod-selector=<pod_selector>]
+----
++
+[NOTE]
+====
+For other options to evacuate pods from a node, see the "Understanding how to evacuate pods on nodes" section. 
+====
+
+. De-allocate the node by running the following command:
++
+[source,terminal]
+----
+$ az vm deallocate -n <node_name> -g <cluster_resource_group>
+----
+
+. Set the `encryptionAtHost` property to `true` by running the following command:
++
+[source,terminal]
+----
+$ az vm update -n <node_name> -g <cluster_resource_group> --set securityProfile.encryptionAtHost=true
+----
+
+. Start the node by running the following commands:
++
+[source,terminal]
+----
+$ az vm start -n <node_name> -g <cluster_resource_group>
+----
+
+. Mark the node as schedulable by using the following command:
++
+[source,terminal]
+----
+$ oc adm uncordon <node_name>
+----
+
+. Verify that all cluster Operators are available:
++
+[source,terminal]
+----
+$ oc get clusteroperators
+----
++
+All Operators should show `AVAILABLE=True`, `PROGRESSING=False`, and `DEGRADED=False`.
+
+. Repeat the above steps on all the nodes that run `encryptionAtHost`.
+
+[NOTE]
+====
+If you want to enable encryption for your host during cluster installation, specify the following parameters in the `install-config.yaml` file:
+* `compute.platform.azure.encryptionAtHost`
+* `controlPlane.platform.azure.encryptionAtHost`
+* `platform.azure.defaultMachinePlatform.encryptionAtHost`
+====