Use managed VNET for Azure CNI overlay

The instructions for creating a cluster with Azure CNI overlay say
to create a VNET and subnet. However, Azure CNI overlay supports
managed VNETs, so this step is unnecessary.

Simplify the instructions by removing the VNET/subnet creation
and --vnet-subnet-id parameter for Azure CNI overlay clusters.

Also remove the --node-count parameter in the Cilium instructions
for consistency with the Azure CNI overlay documentation.
The default value of three nodes is sufficient.

Author: Will Daly

articles/aks/azure-cni-overlay.md

@@ -129,31 +129,15 @@ az provider register --namespace Microsoft.ContainerService
 
 ## Set up overlay clusters
 
-The following steps create a new virtual network with a subnet for the cluster nodes and an AKS cluster that uses Azure CNI Overlay.
-
-1. Create a virtual network with a subnet for the cluster nodes. Replace the values for the variables `resourceGroup`, `vnet` and `location`.
-
-    ```azurecli-interactive
-    resourceGroup="myResourceGroup"
-    vnet="myVirtualNetwork"
-    location="westcentralus"
-    
-    # Create the resource group
-    az group create --name $resourceGroup --location $location
-    
-    # Create a VNet and a subnet for the cluster nodes 
-    az network vnet create -g $resourceGroup --location $location --name $vnet --address-prefixes 10.0.0.0/8 -o none
-    az network vnet subnet create -g $resourceGroup --vnet-name $vnet --name nodesubnet --address-prefix 10.10.0.0/16 -o none
-    ```
-
-2. Create a cluster with Azure CNI Overlay. Use the argument `--network-plugin-mode` to specify that this is an overlay cluster. If the pod CIDR is not specified then AKS assigns a default space, viz. 10.244.0.0/16. Replace the values for the variables `clusterName` and `subscription`.
-
-    ```azurecli-interactive
-    clusterName="myOverlayCluster"
-    subscription="aaaaaaa-aaaaa-aaaaaa-aaaa"
-    
-    az aks create -n $clusterName -g $resourceGroup --location $location --network-plugin azure --network-plugin-mode overlay --pod-cidr 192.168.0.0/16 --vnet-subnet-id /subscriptions/$subscription/resourceGroups/$resourceGroup/providers/Microsoft.Network/virtualNetworks/$vnet/subnets/nodesubnet
-    ```
+Create a cluster with Azure CNI Overlay. Use the argument `--network-plugin-mode` to specify that this is an overlay cluster. If the pod CIDR is not specified then AKS assigns a default space, viz. 10.244.0.0/16. Replace the values for the variables `clusterName`, `resourceGroup`, and `location`.
+
+```azurecli-interactive
+clusterName="myOverlayCluster"
+resourceGroup="myResourceGroup"
+location="westcentralus"
+
+az aks create -n $clusterName -g $resourceGroup --location $location --network-plugin azure --network-plugin-mode overlay --pod-cidr 192.168.0.0/16
+```
 
 ## Next steps
 
@@ -162,4 +146,4 @@ To learn how to utilize AKS with your own Container Network Interface (CNI) plug
 <!-- LINKS - internal -->
 [az-provider-register]: /cli/azure/provider#az-provider-register
 [az-feature-register]: /cli/azure/feature#az-feature-register
-[az-feature-show]: /cli/azure/feature#az-feature-show
+[az-feature-show]: /cli/azure/feature#az-feature-show

articles/aks/azure-cni-powered-by-cilium.md

@@ -112,7 +112,6 @@ Create the cluster using `--enable-cilium-dataplane`:
 ```azurecli-interactive
 az aks create -n <clusterName> -g <resourceGroupName> -l <location> \
   --max-pods 250 \
-  --node-count 2 \
   --network-plugin azure \
   --vnet-subnet-id /subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Network/virtualNetworks/<vnetName>/subnets/nodesubnet \
   --pod-subnet-id /subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Network/virtualNetworks/<vnetName>/subnets/podsubnet \
@@ -121,29 +120,13 @@ az aks create -n <clusterName> -g <resourceGroupName> -l <location> \
 
 ### Option 2: Assign IP addresses from an overlay network
 
-Run these commands to create a resource group and VNet with a single subnet:
-
-```azurecli-interactive
-# Create the resource group
-az group create --name <resourceGroupName> --location <location>
-```
-
-```azurecli-interactive
-# Create a VNet with a subnet for nodes and a subnet for pods
-az network vnet create -g <resourceGroupName> --location <location> --name <vnetName> --address-prefixes <address prefix, example: 10.0.0.0/8> -o none 
-az network vnet subnet create -g <resourceGroupName> --vnet-name <vnetName> --name nodesubnet --address-prefixes <address prefix, example: 10.240.0.0/16> -o none 
-```
-
-Then create the cluster using `--enable-cilium-dataplane`:
+Run this commands to create a cluster with an overlay network and Cilium. Replace the values for `<clusterName>`, `<resourceGroupName>`, and `<location>`:
 
 ```azurecli-interactive
 az aks create -n <clusterName> -g <resourceGroupName> -l <location> \
-  --max-pods 250 \
-  --node-count 2 \
   --network-plugin azure \
   --network-plugin-mode overlay \
   --pod-cidr 192.168.0.0/16 \
-  --vnet-subnet-id /subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.Network/virtualNetworks/<vnetName>/subnets/nodesubnet \
   --enable-cilium-dataplane
 ```