[OSDOCS-19525]: Autoscaling docs for self-managed hosted clusters on Azure

Author: lahinson

hosted_control_planes/hcp-deploy/hcp-deploy-azure.adoc

@@ -99,11 +99,7 @@ include::modules/hcp-azure-private-access.adoc[leveloffset=+2]
 
 include::modules/hcp-azure-private-ts.adoc[leveloffset=+2]
 
-// include::modules/hcp-azure-autoscaling.adoc[leveloffset=+1]
-
-// include::modules/hcp-azure-hc-config-params.adoc[leveloffset=+1]
-
-// include::modules/hcp-azure-nodepool-config-params.adoc[leveloffset=+2]
+include::modules/hcp-azure-autoscaling.adoc[leveloffset=+1]
 
 include::modules/hcp-azure-delete.adoc[leveloffset=+1]
 

modules/hcp-azure-autoscaling.adoc

@@ -0,0 +1,72 @@
+//Module included in the following assemblies:
+// hosted_control_planes/hcp-deploy/hcp-deploy-azure.adoc
+
+:_mod-docs-content-type: REFERENCE
+[id="hcp-azure-autoscaling_{context}"]
+= Example: Autoscaling a hosted cluster on {azure-short}
+
+[role="_abstract"]
+To balance node pools on your {azure-short} hosted cluster, you can configure autoscaling for the cluster.
+
+When you scale up `NodePool` objects, the Cluster API Provider for {azure-short} provisions individual {azure-short} virtual machines.
+
+To configure autoscaling for a hosted cluster on {azure-short}, you edit the `spec.autoscaling` parameters in the `HostedCluster` resource. The following example shows a `HostedCluster` resource with 2 {azure-short} node pools.
+
+[NOTE]
+====
+This example shows only the autoscaling-related fields.
+====
+
+[source,yaml]
+----
+apiVersion: hypershift.openshift.io/v1beta1
+kind: HostedCluster
+metadata:
+  name: my-cluster
+  namespace: my-cluster-namespace
+spec:
+  autoscaling:
+    scaling: ScaleUpAndScaleDown
+    maxNodesTotal: 12
+    expanders:
+      - Random
+    scaleDown:
+      delayAfterAddSeconds: 300
+      unneededDurationSeconds: 600
+      utilizationThresholdPercent: 40
+    balancingIgnoredLabels:
+      - "custom.label/environment"
+    maxFreeDifferenceRatioPercent: 70
+---
+apiVersion: hypershift.openshift.io/v1beta1
+kind: NodePool
+metadata:
+  name: my-cluster-nodepool-1
+  namespace: my-cluster-namespace
+spec:
+  clusterName: my-cluster
+  autoScaling:
+    min: 1
+    max: 6
+  platform:
+    azure:
+      vmSize: Standard_D4s_v3
+      # ... 
+---
+apiVersion: hypershift.openshift.io/v1beta1
+kind: NodePool
+metadata:
+  name: my-cluster-nodepool-2
+  namespace: my-cluster-namespace
+spec:
+  clusterName: my-cluster
+  autoScaling:
+    min: 1
+    max: 6
+  platform:
+    azure:
+      vmSize: Standard_D4s_v3
+      # ... 
+----
+
+* `spec.autoScaling.min` must be greater than or equal to `1`. Scaling from zero (`autoScaling.min: 0`) is not supported on {azure-short}.