For the first issue, the public IP of the scale set instances is not a separate resource in the Azure portal, we can not use Get-AzureRmNetworkInterface to get the network interface information.
For the second issue, you can create a scale set with public IP per virtual machine by ARM template. You can add a publicIpAddressConfiguration JSON property to the scale set ipConfigurations section.
Note that IpPublicPrefix requires a standard SKU load balancer and public IP address. Here is a working sample.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"vmSku": {
"type": "string",
"defaultValue": "Standard_A1_v2",
"metadata": {
"description": "Size of VMs in the VM Scale Set."
}
},
"windowsOSVersion": {
"type": "string",
"defaultValue": "2019-Datacenter",
"allowedValues": [
"2008-R2-SP1",
"2012-Datacenter",
"2012-R2-Datacenter",
"2016-Datacenter",
"2019-Datacenter"
],
"metadata": {
"description": "The Windows version for the VM. This will pick a fully patched image of this given Windows version. Allowed values: 2008-R2-SP1, 2012-Datacenter, 2012-R2-Datacenter & 2016-Datacenter, 2019-Datacenter."
}
},
"vmssName": {
"type": "string",
"minLength": 3,
"maxLength": 61,
"metadata": {
"description": "String used as a base for naming resources. Must be 3-61 characters in length and globally unique across Azure. A hash is prepended to this string for some resources, and resource-specific information is appended."
}
},
"instanceCount": {
"type": "int",
"defaultValue": 3,
"minValue": 1,
"maxValue": 100,
"metadata": {
"description": "Number of VM instances (100 or less)."
}
},
"singlePlacementGroup": {
"type": "bool",
"defaultValue": true,
"metadata": {
"description": "When true this limits the scale set to a single placement group, of max size 100 virtual machines. NOTE: If singlePlacementGroup is true, it may be modified to false. However, if singlePlacementGroup is false, it may not be modified to true."
}
},
"adminUsername": {
"type": "string",
"defaultValue": "vmssadmin",
"metadata": {
"description": "Admin username on all VMs."
}
},
"adminPassword": {
"type": "securestring",
"metadata": {
"description": "Admin password on all VMs."
}
},
"location": {
"type": "string",
"defaultValue": "[resourceGroup().location]",
"metadata": {
"description": "Location for all resources."
}
},
"platformFaultDomainCount": {
"type": "int",
"defaultValue": 1,
"metadata": {
"description": "Fault Domain count for each placement group."
}
},
"publicIPPrefixes_pubprefix_name": {
"defaultValue": "vmsspublicprefix",
"type": "string"
}
},
"variables": {
"namingInfix": "[toLower(substring(concat(parameters('vmssName'), uniqueString(resourceGroup().id)), 0, 9))]",
"longNamingInfix": "[toLower(parameters('vmssName'))]",
"addressPrefix": "10.0.0.0/16",
"subnetPrefix": "10.0.0.0/24",
"virtualNetworkName": "[concat(variables('namingInfix'), 'vnet')]",
"publicIPAddressName": "[concat(variables('namingInfix'), 'pip')]",
"subnetName": "[concat(variables('namingInfix'), 'subnet')]",
"loadBalancerName": "[concat(variables('namingInfix'), 'lb')]",
"publicIPAddressID": "[resourceId('Microsoft.Network/publicIPAddresses',variables('publicIPAddressName'))]",
"lbProbeID": "[resourceId('Microsoft.Network/loadBalancers/probes',variables('loadBalancerName'), 'tcpProbe')]",
"natPoolName": "[concat(variables('namingInfix'), 'natpool')]",
"bePoolName": "[concat(variables('namingInfix'), 'bepool')]",
"lbPoolID": "[resourceId('Microsoft.Network/loadBalancers/backendAddressPools',variables('loadBalancerName'),variables('bePoolName'))]",
"natStartPort": 50000,
"natEndPort": 50119,
"natBackendPort": 3389,
"nicName": "[concat(variables('namingInfix'), 'nic')]",
"ipConfigName": "[concat(variables('namingInfix'), 'ipconfig')]",
"frontEndIPConfigID": "[resourceId('Microsoft.Network/loadBalancers/frontendIPConfigurations',variables('loadBalancerName'),'loadBalancerFrontEnd')]",
"osType": {
"publisher": "MicrosoftWindowsServer",
"offer": "WindowsServer",
"sku": "[parameters('windowsOSVersion')]",
"version": "latest"
},
"imageReference": "[variables('osType')]"
},
"resources": [
{
"type": "Microsoft.Network/loadBalancers",
"apiVersion": "2020-06-01",
"name": "[variables('loadBalancerName')]",
"location": "[parameters('location')]",
"dependsOn": [
"[resourceId('Microsoft.Network/publicIPAddresses', variables('publicIPAddressName'))]"
],
"sku": {
"name": "Standard"
},
"properties": {
"frontendIPConfigurations": [
{
"name": "LoadBalancerFrontEnd",
"properties": {
"publicIPAddress": {
"id": "[variables('publicIPAddressID')]",
"name": "Standard"
}
}
}
],
"backendAddressPools": [
{
"name": "[variables('bePoolName')]"
}
],
"inboundNatPools": [
{
"name": "[variables('natPoolName')]",
"properties": {
"frontendIPConfiguration": {
"id": "[variables('frontEndIPConfigID')]"
},
"protocol": "Tcp",
"frontendPortRangeStart": "[variables('natStartPort')]",
"frontendPortRangeEnd": "[variables('natEndPort')]",
"backendPort": "[variables('natBackendPort')]"
}
}
],
"loadBalancingRules": [
{
"name": "LBRule",
"properties": {
"frontendIPConfiguration": {
"id": "[variables('frontEndIPConfigID')]"
},
"backendAddressPool": {
"id": "[variables('lbPoolID')]"
},
"protocol": "Tcp",
"frontendPort": 80,
"backendPort": 80,
"enableFloatingIP": false,
"idleTimeoutInMinutes": 5,
"probe": {
"id": "[variables('lbProbeID')]"
}
}
}
],
"probes": [
{
"name": "tcpProbe",
"properties": {
"protocol": "Tcp",
"port": 80,
"intervalInSeconds": 5,
"numberOfProbes": 2
}
}
]
}
},
{
"type": "Microsoft.Network/publicIPPrefixes",
"apiVersion": "2020-11-01",
"name": "[parameters('publicIPPrefixes_pubprefix_name')]",
"location": "[parameters('location')]",
"sku": {
"name": "Standard",
"tier": "Regional"
},
"properties": {
"prefixLength": 28,
"publicIPAddressVersion": "IPv4",
"ipTags": []
}
},
{
"type": "Microsoft.Compute/virtualMachineScaleSets",
"apiVersion": "2020-06-01",
"name": "[variables('namingInfix')]",
"location": "[parameters('location')]",
"sku": {
"name": "[parameters('vmSku')]",
"tier": "Standard",
"capacity": "[parameters('instanceCount')]"
},
"dependsOn": [
"[resourceId('Microsoft.Network/loadBalancers', variables('loadBalancerName'))]",
"[resourceId('Microsoft.Network/virtualNetworks', variables('virtualNetworkName'))]",
"[resourceId('Microsoft.Network/publicIPPrefixes',parameters('publicIPPrefixes_pubprefix_name'))]"
],
"properties": {
"overprovision": true,
"upgradePolicy": {
"mode": "Automatic"
},
"singlePlacementGroup": "[parameters('singlePlacementGroup')]",
"platformFaultDomainCount": "[parameters('platformFaultDomainCount')]",
"virtualMachineProfile": {
"storageProfile": {
"osDisk": {
"caching": "ReadWrite",
"createOption": "FromImage"
},
"imageReference": "[variables('imageReference')]"
},
"osProfile": {
"computerNamePrefix": "[variables('namingInfix')]",
"adminUsername": "[parameters('adminUsername')]",
"adminPassword": "[parameters('adminPassword')]"
},
"networkProfile": {
"networkInterfaceConfigurations": [
{
"name": "[variables('nicName')]",
"properties": {
"primary": true,
"ipConfigurations": [
{
"name": "[variables('ipConfigName')]",
"properties": {
"subnet": {
"id": "[resourceId('Microsoft.Network/virtualNetworks/subnets', variables('virtualNetworkName'), variables('subnetName'))]"
},
"loadBalancerBackendAddressPools": [
{
"id": "[variables('lbPoolID')]"
}
],
"loadBalancerInboundNatPools": [
{
"id": "[resourceId('Microsoft.Network/loadBalancers/inboundNatPools', variables('loadBalancerName'), variables('natPoolName'))]"
}
],
"publicipaddressconfiguration": {
"name": "pub1",
"properties": {
"idleTimeoutInMinutes": 15,
"publicIPAddressVersion": "IPv4",
"publicIPPrefix":{
"id": "[resourceId('Microsoft.Network/publicIPPrefixes',parameters('publicIPPrefixes_pubprefix_name'))]"
}
}
}
}
}
]
}
}
]
}
}
}
},
{
"type": "Microsoft.Network/publicIPAddresses",
"apiVersion": "2020-06-01",
"name": "[variables('publicIPAddressName')]",
"location": "[parameters('location')]",
"sku": {
"name": "Standard"
},
"properties": {
"publicIPAllocationMethod": "Static",
"dnsSettings": {
"domainNameLabel": "[variables('longNamingInfix')]"
}
}
},
{
"type": "Microsoft.Network/virtualNetworks",
"apiVersion": "2020-06-01",
"name": "[variables('virtualNetworkName')]",
"location": "[parameters('location')]",
"properties": {
"addressSpace": {
"addressPrefixes": [
"[variables('addressPrefix')]"
]
},
"subnets": [
{
"name": "[variables('subnetName')]",
"properties": {
"addressPrefix": "[variables('subnetPrefix')]"
}
}
]
}
},
{
"type": "Microsoft.Insights/autoscaleSettings",
"apiVersion": "2015-04-01",
"name": "autoscalehost",
"location": "[parameters('location')]",
"dependsOn": [
"[resourceId('Microsoft.Compute/virtualMachineScaleSets/', variables('namingInfix'))]"
],
"properties": {
"name": "autoscalehost",
"targetResourceUri": "[resourceId('Microsoft.Compute/virtualMachineScaleSets', variables('namingInfix'))]",
"enabled": true,
"profiles": [
{
"name": "Profile1",
"capacity": {
"minimum": "1",
"maximum": "10",
"default": "1"
},
"rules": [
{
"metricTrigger": {
"metricName": "Percentage CPU",
"metricResourceUri": "[resourceId('Microsoft.Compute/virtualMachineScaleSets', variables('namingInfix'))]",
"timeGrain": "PT1M",
"statistic": "Average",
"timeWindow": "PT5M",
"timeAggregation": "Average",
"operator": "GreaterThan",
"threshold": 50
},
"scaleAction": {
"direction": "Increase",
"type": "ChangeCount",
"value": "1",
"cooldown": "PT5M"
}
},
{
"metricTrigger": {
"metricName": "Percentage CPU",
"metricResourceUri": "[resourceId('Microsoft.Compute/virtualMachineScaleSets', variables('namingInfix'))]",
"timeGrain": "PT1M",
"statistic": "Average",
"timeWindow": "PT5M",
"timeAggregation": "Average",
"operator": "LessThan",
"threshold": 30
},
"scaleAction": {
"direction": "Decrease",
"type": "ChangeCount",
"value": "1",
"cooldown": "PT5M"
}
}
]
}
]
}
}
]
}
Also, you can get the specified public IP address of an instance in a virtual machine scale set with the REST API.
GET https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Compute/virtualMachineScaleSets/{virtualMachineScaleSetName}/virtualMachines/{virtualmachineIndex}/networkInterfaces/{networkInterfaceName}/ipconfigurations/{ipConfigurationName}/publicipaddresses/{publicIpAddressName}?api-version=2018-10-01
