Tutorial: Connect to Virtual Machine Scale Set instances using the Azure CLI

A Virtual Machine Scale Set allows you to deploy and manage a set of virtual machines. Throughout the lifecycle of a Virtual Machine Scale Set, you may need to run one or more management tasks. In this tutorial you learn how to:

If you don't have an Azure subscription, create an Azure free account before you begin.

Prerequisites

• Use the Bash environment in Azure Cloud Shell. For more information, see Quickstart for Bash in Azure Cloud Shell.

  

• If you prefer to run CLI reference commands locally, install the Azure CLI. If you're running on Windows or macOS, consider running Azure CLI in a Docker container. For more information, see How to run the Azure CLI in a Docker container.

  • If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For other sign-in options, see Sign in with the Azure CLI.

  • When you're prompted, install the Azure CLI extension on first use. For more information about extensions, see Use extensions with the Azure CLI.

  • Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

This article requires version 2.0.29 or later of the Azure CLI. If using Azure Cloud Shell, the latest version is already installed.

List instances in a scale set

If you do not have a scale set already created, see Tutorial: Create and manage a Virtual Machine Scale Set with the Azure CLI

List all the instances in your Virtual Machine Scale Set.

az vmss list-instances \
  --resource-group myResourceGroup \
  --name myScaleSet \
  --output table

Location    Name                 ResourceGroup
----------  -------------------  ---------------
eastus      myScaleSet_0e7d4d21  myResourceGroup
eastus      myScaleSet_39379fc3  myResourceGroup

Get NIC information

Use az vm nic list and the name of the individual VM instance to find the NIC name.

az vm nic list \
  --resource-group myResourceGroup
  --vm-name myScaleSet_0e7d4d21

[
  {
    "deleteOption": "Delete",
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkInterfaces/mysca2215Nic-828c525a",
    "primary": true,
    "resourceGroup": "myResourceGroup"
  }
]

Using the VM name and NIC name, get the private IP address of the NIC, the Inbound NAT rule name and load balancer name using az vm nic show.

az vm nic show --resource-group myResourceGroup --vm-name myScaleSet_0e7d4d21 --nic mysca2215Nic-828c525a

{
  "enableAcceleratedNetworking": false,
  "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkInterfaces/mysca2215Nic-828c525a",
  "ipConfigurations": [
    {
      "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkInterfaces/mysca2215Nic-828c525a/ipConfigurations/mysca2215IPConfig",
      "loadBalancerBackendAddressPools": [
        {
          "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/loadBalancers/myScaleSetLB/backendAddressPools/myScaleSetLBBEPool",
        }
      ],
      "name": "mysca2215IPConfig",
      "primary": true,
      "privateIpAddress": "10.0.0.5",
      "privateIpAddressVersion": "IPv4",
      "privateIpAllocationMethod": "Dynamic",
      "provisioningState": "Succeeded",
      "resourceGroup": "myResourceGroup",
      "subnet": {
        "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/virtualNetworks/myScaleSetVNET/subnets/myScaleSetSubnet",
        "resourceGroup": "myResourceGroup",
      },
      "type": "Microsoft.Network/networkInterfaces/ipConfigurations",
    }
  ],
  "location": "eastus",
  "name": "mysca2215Nic-828c525a",
  "networkSecurityGroup": {
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkSecurityGroups/myScaleSetNSG",
    "resourceGroup": "myResourceGroup",
  },
  "nicType": "Standard",
  "primary": true,
  "provisioningState": "Succeeded",
  "resourceGroup": "myResourceGroup",
  "tapConfigurations": [],
  "type": "Microsoft.Network/networkInterfaces",
  "virtualMachine": {
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachines/myScaleSet_0e7d4d21",
    "resourceGroup": "myResourceGroup"
  },
}

Get backend pool details

Using the backend pool name and load balancer name, get the port for the private IP address of the instance you want to connect to with az network lb list-mapping.

az network lb list-mapping --backend-pool-name myScaleSetLBBEPool --resource-group myResourceGroup --name myScaleSetLB --request ip=10.0.0.5

{
  "inboundNatRulePortMappings": [
    {
      "backendPort": 22,
      "frontendPort": 50001,
      "inboundNatRuleName": "NatRule",
      "protocol": "Tcp"
    }
  ]
}

Get public IP of load balancer

Get the public IP of the load balancer using az network public-ip list.

az network public-ip list --resource-group myResourceGroup

[
  {
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/publicIPAddresses/myScaleSetLBPublicIP",
    "idleTimeoutInMinutes": 4,
    "ipAddress": "20.172.211.239",
    "ipConfiguration": {
      "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/loadBalancers/myScaleSetLB/frontendIPConfigurations/loadBalancerFrontEnd",
      "resourceGroup": "myResourceGroup"
    },
    "ipTags": [],
    "location": "eastus",
    "name": "myScaleSetLBPublicIP",
    "provisioningState": "Succeeded",
    "publicIPAddressVersion": "IPv4",
    "publicIPAllocationMethod": "Static",
    "resourceGroup": "myResourceGroup",
    "sku": {
      "name": "Standard",
      "tier": "Regional"
    },
    "tags": {},
    "type": "Microsoft.Network/publicIPAddresses"
  }
]

Connect to your instance

SSH to the machine using the load balancer IP and the port of the machine you want to connect to.

ssh [email protected] -p 50000

Next steps

In this tutorial, you learned how to list the instances in your scale set and connect via SSH to an individual instance.