Connect with RDP to Azure Kubernetes Service (AKS) cluster Windows Server nodes for maintenance or troubleshooting

Throughout the lifecycle of your Azure Kubernetes Service (AKS) cluster, you may need to access an AKS Windows Server node. This access could be for maintenance, log collection, or other troubleshooting operations. You can access the AKS Windows Server nodes using RDP. For security purposes, the AKS nodes aren't exposed to the internet.

Alternatively, if you want to SSH to your AKS Windows Server nodes, you need access to the same key-pair that was used during cluster creation. Follow the steps in SSH into Azure Kubernetes Service (AKS) cluster nodes.

This article shows you how to create an RDP connection with an AKS node using their private IP addresses.

Before you begin

Azure CLI

This article assumes that you have an existing AKS cluster with a Windows Server node. If you need an AKS cluster, see the article on creating an AKS cluster with a Windows container using the Azure CLI. You need the Windows administrator username and password for the Windows Server node you want to troubleshoot. You also need an RDP client such as Microsoft Remote Desktop.

If you need to reset the password, use az aks update to change the password.

az aks update --resource-group myResourceGroup --name myAKSCluster --windows-admin-password $WINDOWS_ADMIN_PASSWORD

If you need to reset the username and password, see Reset Remote Desktop Services or its administrator password in a Windows VM.

You also need the Azure CLI version 2.0.61 or later installed and configured. Run az --version to find the version. If you need to install or upgrade, see Install Azure CLI.

Azure PowerShell

This article assumes that you have an existing AKS cluster with a Windows Server node. If you need an AKS cluster, see the article on creating an AKS cluster with a Windows container using the Azure PowerShell. You need the Windows administrator username and password for the Windows Server node you want to troubleshoot. You also need an RDP client such as Microsoft Remote Desktop.

If you need to reset the password, use Set-AzAksCluster to change the password.

$cluster = Get-AzAksCluster -ResourceGroupName myResourceGroup -Name myAKSCluster
$cluster.WindowsProfile.AdminPassword = $WINDOWS_ADMIN_PASSWORD
$cluster | Set-AzAksCluster

If you need to reset the username and password, see Reset Remote Desktop Services or its administrator password in a Windows VM .

You also need the Azure PowerShell version 7.5.0 or later installed and configured. Run Get-InstalledModule -Name Az to find the version. If you need to install or upgrade, see Install Azure PowerShell.

Deploy a virtual machine to the same subnet as your cluster

The Windows Server nodes of your AKS cluster don't have externally accessible IP addresses. To make an RDP connection, you can deploy a virtual machine with a publicly accessible IP address to the same subnet as your Windows Server nodes.

The following example creates a virtual machine named myVM in the myResourceGroup resource group.

Azure CLI

You need to get the subnet ID used by your Windows Server node pool and query for:

• The cluster's node resource group
• The virtual network
• The subnet's name
• The subnet ID

CLUSTER_RG=$(az aks show --resource-group myResourceGroup --name myAKSCluster --query nodeResourceGroup -o tsv)
VNET_NAME=$(az network vnet list --resource-group $CLUSTER_RG --query [0].name -o tsv)
SUBNET_NAME=$(az network vnet subnet list --resource-group $CLUSTER_RG --vnet-name $VNET_NAME --query [0].name -o tsv)
SUBNET_ID=$(az network vnet subnet show --resource-group $CLUSTER_RG --vnet-name $VNET_NAME --name $SUBNET_NAME --query id -o tsv)

Now that you've the SUBNET_ID, run the following command in the same Azure Cloud Shell window to create the VM:

PUBLIC_IP_ADDRESS="myVMPublicIP"

az vm create \
    --resource-group myResourceGroup \
    --name myVM \
    --image win2019datacenter \
    --admin-username azureuser \
    --admin-password {admin-password} \
    --subnet $SUBNET_ID \
    --nic-delete-option delete \
    --os-disk-delete-option delete \
    --nsg "" \
    --public-ip-address $PUBLIC_IP_ADDRESS \
    --query publicIpAddress -o tsv

The following example output shows the VM has been successfully created and displays the public IP address of the virtual machine.

13.62.204.18

Record the public IP address of the virtual machine. You'll use this address in a later step.

Azure PowerShell

You'll need to get the subnet ID used by your Windows Server node pool and query for:

• The cluster's node resource group
• The virtual network
• The subnet's name and address prefix
• The subnet ID

$CLUSTER_RG = (Get-AzAksCluster -ResourceGroupName myResourceGroup -Name myAKSCluster).nodeResourceGroup
$VNET_NAME = (Get-AzVirtualNetwork -ResourceGroupName $CLUSTER_RG).Name
$ADDRESS_PREFIX = (Get-AzVirtualNetwork -ResourceGroupName $CLUSTER_RG).AddressSpace | Select-Object -ExpandProperty AddressPrefixes
$SUBNET_NAME = (Get-AzVirtualNetwork -ResourceGroupName $CLUSTER_RG).Subnets[0].Name
$SUBNET_ADDRESS_PREFIX = (Get-AzVirtualNetwork -ResourceGroupName $CLUSTER_RG).Subnets[0] | Select-Object -ExpandProperty AddressPrefix

Now that you have the VNet and subnet details, run the following commands in the same Azure Cloud Shell window to create the public IP address and VM:

$ipParams = @{
    Name              = 'myPublicIP'
    ResourceGroupName = 'myResourceGroup'
    Location          = 'eastus'
    AllocationMethod  = 'Dynamic'
    IpAddressVersion  = 'IPv4'
}
New-AzPublicIpAddress @ipParams

$vmParams = @{
    ResourceGroupName            = 'myResourceGroup'
    Name                         = 'myVM'
    Image                        = 'win2019datacenter'
    Credential                   = Get-Credential azureuser
    VirtualNetworkName           = $VNET_NAME
    AddressPrefix                = $ADDRESS_PREFIX
    SubnetName                   = $SUBNET_NAME
    SubnetAddressPrefix          = $SUBNET_ADDRESS_PREFIX
    PublicIpAddressName          = 'myPublicIP'
    OSDiskDeleteOption           = 'Delete'
    NetworkInterfaceDeleteOption = 'Delete'
    DataDiskDeleteOption         = 'Delete'
}
New-AzVM @vmParams

(Get-AzPublicIpAddress -ResourceGroupName myResourceGroup -Name myPublicIP).IpAddress

The following example output shows the VM has been successfully created and displays the public IP address of the virtual machine.

13.62.204.18

Record the public IP address of the virtual machine and use the address in a later step.

Allow access to the virtual machine

AKS node pool subnets are protected with NSGs (Network Security Groups) by default. To get access to the virtual machine, you'll have to enabled access in the NSG.

Note

The NSGs are controlled by the AKS service. Any change you make to the NSG will be overwritten at any time by the control plane.

Azure CLI

First, get the resource group and name of the NSG to add the rule to:

CLUSTER_RG=$(az aks show --resource-group myResourceGroup --name myAKSCluster --query nodeResourceGroup -o tsv)
NSG_NAME=$(az network nsg list --resource-group $CLUSTER_RG --query [].name -o tsv)

Then, create the NSG rule:

az network nsg rule create \
 --name tempRDPAccess \
 --resource-group $CLUSTER_RG \
 --nsg-name $NSG_NAME \
 --priority 100 \
 --destination-port-range 3389 \
 --protocol Tcp \
 --description "Temporary RDP access to Windows nodes"

Azure PowerShell

First, get the resource group and name of the NSG to add the rule to:

$CLUSTER_RG = (Get-AzAksCluster -ResourceGroupName myResourceGroup -Name myAKSCluster).nodeResourceGroup
$NSG_NAME = (Get-AzNetworkSecurityGroup -ResourceGroupName $CLUSTER_RG).Name

Then, create the NSG rule:

$nsgRuleParams = @{
    Name                     = 'tempRDPAccess'
    Access                   = 'Allow'
    Direction                = 'Inbound'
    Priority                 = 100
    SourceAddressPrefix      = 'Internet'
    SourcePortRange          = '*'
    DestinationAddressPrefix = '*'
    DestinationPortRange     = '3389'
    Protocol                 = 'Tcp'
    Description              = 'Temporary RDP access to Windows nodes'
}
Get-AzNetworkSecurityGroup -Name $NSG_NAME -ResourceGroupName $CLUSTER_RG | Add-AzNetworkSecurityRuleConfig @nsgRuleParams | Set-AzNetworkSecurityGroup

Get the node address

Azure CLI

To manage a Kubernetes cluster, you use kubectl, the Kubernetes command-line client. If you use Azure Cloud Shell, kubectl is already installed. To install kubectl locally, use the az aks install-cli command:

az aks install-cli

To configure kubectl to connect to your Kubernetes cluster, use the az aks get-credentials command. This command downloads credentials and configures the Kubernetes CLI to use them.

az aks get-credentials --resource-group myResourceGroup --name myAKSCluster

Azure PowerShell

To manage a Kubernetes cluster, you use kubectl, the Kubernetes command-line client. If you use Azure Cloud Shell, kubectl is already installed. To install kubectl locally, use the Install-AzAksKubectl cmdlet:

Install-AzAksKubectl

To configure kubectl to connect to your Kubernetes cluster, use the Import-AzAksCredential cmdlet. This command downloads credentials and configures the Kubernetes CLI to use them.

Import-AzAksCredential -ResourceGroupName myResourceGroup -Name myAKSCluster

List the internal IP address of the Windows Server nodes using the kubectl get command:

kubectl get nodes -o wide

The following example output shows the internal IP addresses of all the nodes in the cluster, including the Windows Server nodes.

$ kubectl get nodes -o wide
NAME                                STATUS   ROLES   AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                    KERNEL-VERSION      CONTAINER-RUNTIME
aks-nodepool1-42485177-vmss000000   Ready    agent   18h   v1.12.7   10.240.0.4    <none>        Ubuntu 16.04.6 LTS          4.15.0-1040-azure   docker://3.0.4
aksnpwin000000                      Ready    agent   13h   v1.12.7   10.240.0.67   <none>        Windows Server Datacenter   10.0.17763.437

Record the internal IP address of the Windows Server node you wish to troubleshoot. You'll use this address in a later step.

Connect to the virtual machine and node

Connect to the public IP address of the virtual machine you created earlier using an RDP client such as Microsoft Remote Desktop.

After you have connected to your virtual machine, connect to the internal IP address of the Windows Server node you want to troubleshoot using an RDP client from within your virtual machine.

You're now connected to your Windows Server node.

You can now run any troubleshooting commands in the cmd window. Since Windows Server nodes use Windows Server Core, there's not a full GUI or other GUI tools when you connect to a Windows Server node over RDP.

Remove RDP access

Azure CLI

When done, exit the RDP connection to the Windows Server node then exit the RDP session to the virtual machine. After you exit both RDP sessions, delete the virtual machine with the az vm delete command:

# Delete the virtual machine
az vm delete \
 --resource-group myResourceGroup \
 --name myVM

Delete the public IP associated with the virtual machine:

az network public-ip delete \
 --resource-group myResourceGroup \
 --name $PUBLIC_IP_ADDRESS

Delete the NSG rule:

CLUSTER_RG=$(az aks show --resource-group myResourceGroup --name myAKSCluster --query nodeResourceGroup -o tsv)
NSG_NAME=$(az network nsg list --resource-group $CLUSTER_RG --query [].name -o tsv)
az network nsg rule delete \
 --resource-group $CLUSTER_RG \
 --nsg-name $NSG_NAME \
 --name tempRDPAccess

Azure PowerShell

When done, exit the RDP connection to the Windows Server node then exit the RDP session to the virtual machine. After you exit both RDP sessions, delete the virtual machine with the Remove-AzVM command:

Remove-AzVM -ResourceGroupName myResourceGroup -Name myVM

Delete the public IP associated with the virtual machine:

Remove-AzPublicIpAddress -ResourceGroupName myResourceGroup -Name myPublicIP

Delete the NSG rule:

$CLUSTER_RG = (Get-AzAksCluster -ResourceGroupName myResourceGroup -Name myAKSCluster).nodeResourceGroup
$NSG_NAME = (Get-AzNetworkSecurityGroup -ResourceGroupName $CLUSTER_RG).Name

Get-AzNetworkSecurityGroup -Name $NSG_NAME -ResourceGroupName $CLUSTER_RG | Remove-AzNetworkSecurityRuleConfig -Name tempRDPAccess | Set-AzNetworkSecurityGroup

Delete the NSG created by default from New-AzVM:

Remove-AzNetworkSecurityGroup -ResourceGroupName myResourceGroup -Name myVM

Connect with Azure Bastion

Alternatively, you can use Azure Bastion to connect to your Windows Server node.

Deploy Azure Bastion

To deploy Azure Bastion, you'll need to find the virtual network your AKS cluster is connected to.

1. In the Azure portal, go to Virtual networks. Select the virtual network your AKS cluster is connected to.
2. Under Settings, select Bastion, then select Deploy Bastion. Wait until the process is finished before going to the next step.

Connect to your Windows Server nodes using Azure Bastion

Go to the node resource group of the AKS cluster. Run the command below in the Azure Cloud Shell to get the name of your node resource group:

Azure CLI

az aks show --name myAKSCluster --resource-group myResourceGroup --query 'nodeResourceGroup' -o tsv

Azure PowerShell

(Get-AzAksCluster -ResourceGroupName myResourceGroup -Name myAKSCluster).nodeResourceGroup

1. Select Overview, and select your Windows node pool virtual machine scale set.
2. Under Settings, select Instances. Select a Windows server node that you'd like to connect to.
3. Under Support + troubleshooting, select Bastion.
4. Enter the credentials you set up when the AKS cluster was created. Select Connect.

You can now run any troubleshooting commands in the cmd window. Since Windows Server nodes use Windows Server Core, there's not a full GUI or other GUI tools when you connect to a Windows Server node over RDP.

Note

If you close out of the terminal window, press CTRL + ALT + End, select Task Manager, select More details, select File, select Run new task, and enter cmd.exe to open another terminal. You can also logout and re-connect with Bastion.

Remove Bastion access

When you're finished, exit the Bastion session and remove the Bastion resource.

1. In the Azure portal, go to Bastion and select the Bastion resource you created.
2. At the top of the page, select Delete. Wait until the process is complete before proceeding to the next step.
3. In the Azure portal, go to Virtual networks. Select the virtual network that your AKS cluster is connected to.
4. Under Settings, select Subnet, and delete the AzureBastionSubnet subnet that was created for the Bastion resource.

Next steps

If you need more troubleshooting data, you can view the Kubernetes primary node logs or Azure Monitor.