Obtain IP of Internal Load Balancer in App Service Environment - azure

Question

I am developing ARM template to deploy an App Service Environment v2 configured with an Internal Load Balancer (ILB ASE). Is there a way to grab the Virtual IP (VIP) address that the Internal Load Balancer gets from the vnet it is attached to as an output? When I look at the properties of the ASE via PowerShell after it is provisioned, I do not see a property for the IP address, or for the load balancer.

Answer 1

After much research and testing...there is currently no way to do this as an output from the ARM template. Here are the ways that the value can be collected:
Via Resource Explorer...although this is not very helpful for doing it programmatically but it did help me figure out the other 2 ways
Using PowerShell to query the management.azure.com API but you have to publish an app with the appropriate permissions and assign the app to have permissions in the subscription you are trying to query resources from
Using Azure CLI. This method turned out to be the easiest.
I needed this value to fully automate the deployment of an App Gateway sitting in front of an ILB ASE. I use Terraform for deployment automation and I run the Terraform configs from Azure Cloud Shell. I kick off my deployments with a shell script where I dynamically get the storage account key to the storage account where I store state files. I then query the ILB ASE to get the IP address and set it to a variable that I then pass into Terraform
Below is a copy of the shell script I use:
#!/bin/bash
set -eo pipefail
# The block below will grab the access key for the storage account that is used
# to store state files
subscription_name="<my_subscription_name>"
tfstate_storage_resource_group="terraform-state-rg"
tfstate_storage_account="<name_of_statefile_storage_account>"
subscription_id="my_subscription_id>"
ilbase_rg_name="<name_of_resourcegroup_where_ase_is_deployed>"
ilbase_name="<name_of_ase>"
az account set --subscription "$subscription_name"
tfstate_storage_access_key=$(
az storage account keys list \
--resource-group "$tfstate_storage_resource_group" \
--account-name "$tfstate_storage_account" \
--query '[0].value' -o tsv
)
echo ""
echo "Terraform state storage account access key:"
echo $tfstate_storage_access_key
echo ""
# The block below will get the Virtual IP of the ASE Internal Load Balancer
# which will be used to create the App GW
ilbase_virtual_ip=$(
az resource show \
--ids "/subscriptions/$subscription_id/resourceGroups/$ilbase_rg_name/providers/Microsoft.Web/hostingEnvironments/$ilbase_name/capacities/virtualip" \
--query "additionalProperties.internalIpAddress"
)
echo ""
echo "ASE internal load balancer IP:"
echo $ilbase_virtual_ip
echo ""
terraform plan \
-var "tfstate_access_key=$tfstate_storage_access_key" \
-var "ilbase_virtual_ip=$ilbase_virtual_ip"

Answer 2

You can use output like this:
"outputs": {
"privateIp": {
"type": "string",
"value": "[reference(parameters('lbname')).frontendIPConfigurations[0].properties.privateIPAddress]"
}
}
Here is my template, create one Vnet and one internal load balancer:
{
"$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"vnetName": {
"type": "string",
"defaultValue": "VNet1",
"metadata": {
"description": "VNet name"
}
},
"vnetAddressPrefix": {
"type": "string",
"defaultValue": "10.0.0.0/16",
"metadata": {
"description": "Address prefix"
}
},
"subnet1Prefix": {
"type": "string",
"defaultValue": "10.0.0.0/24",
"metadata": {
"description": "Subnet 1 Prefix"
}
},
"subnet1Name": {
"type": "string",
"defaultValue": "Subnet1",
"metadata": {
"description": "Subnet 1 Name"
}
},
"subnet2Prefix": {
"type": "string",
"defaultValue": "10.0.1.0/24",
"metadata": {
"description": "Subnet 2 Prefix"
}
},
"subnet2Name": {
"type": "string",
"defaultValue": "Subnet2",
"metadata": {
"description": "Subnet 2 Name"
}
},
"lbname": {
"defaultValue": "jasonlbb",
"type": "String"
}
},
"variables": {
"virtualnetworkname" : "vnet1",
"apiVersion": "2015-06-15",
"vnetID": "[resourceId('Microsoft.Network/virtualNetworks',variables('virtualnetworkname'))]",
"subnetRef": "[concat(variables('vnetID'),'/subnets/',parameters('subnet1Name'))]"
},
"resources": [
{
"apiVersion": "2015-06-15",
"type": "Microsoft.Network/virtualNetworks",
"name": "[parameters('vnetName')]",
"location": "[resourceGroup().location]",
"properties": {
"addressSpace": {
"addressPrefixes": [
"[parameters('vnetAddressPrefix')]"
]
},
"subnets": [
{
"name": "[parameters('subnet1Name')]",
"properties": {
"addressPrefix": "[parameters('subnet1Prefix')]"
}
},
{
"name": "[parameters('subnet2Name')]",
"properties": {
"addressPrefix": "[parameters('subnet2Prefix')]"
}
}
]
}
},
{
"apiVersion": "2015-05-01-preview",
"type": "Microsoft.Network/loadBalancers",
"name": "[parameters('lbname')]",
"location": "[resourceGroup().location]",
"dependsOn": [
"[variables('vnetID')]"
],
"properties": {
"frontendIPConfigurations": [
{
"properties": {
"subnet": {
"id": "[variables('subnetRef')]"
},
"privateIPAllocationMethod": "Dynamic"
},
"name": "LoadBalancerFrontend"
}
],
"backendAddressPools": [
{
"name": "BackendPool1"
}
],
"loadBalancingRules": [
{
"properties": {
"frontendIPConfiguration": {
"id": "[concat(resourceId('Microsoft.Network/loadBalancers', parameters('lbname')), '/frontendIpConfigurations/LoadBalancerFrontend')]"
},
"backendAddressPool": {
"id": "[concat(resourceId('Microsoft.Network/loadBalancers', parameters('lbname')), '/backendAddressPools/BackendPool1')]"
},
"probe": {
"id": "[concat(resourceId('Microsoft.Network/loadBalancers', parameters('lbname')), '/probes/lbprobe')]"
},
"protocol": "Tcp",
"frontendPort": 80,
"backendPort": 80,
"idleTimeoutInMinutes": 15
},
"Name": "lbrule"
}
],
"probes": [
{
"properties": {
"protocol": "Tcp",
"port": 80,
"intervalInSeconds": 15,
"numberOfProbes": 2
},
"name": "lbprobe"
}
]
}
}
],
"outputs": {
"privateIp": {
"type": "string",
"value": "[reference(parameters('lbname')).frontendIPConfigurations[0].properties.privateIPAddress]"
}
}
}
Here is the screenshot about the result:
Hope this helps.

Answer 3

If you’re using Terraform, here’s how I got it working. Had to use the external data source in Terraform coupled with Azure CLI and jq to get around the bugs in Azure and the Terraform External Data provider.
# As of writing, the ASE ARM deployment don’t return the IP address of the ILB
# ASE. This workaround querys Azure’s API to get the values we need for use
# elsewhere in the script.
# See this https://stackoverflow.com/a/49436100
data “external” “app_service_environment_ilb_ase_ip_address” {
# This calls the Azure CLI then passes the value to jq to return JSON as a single
# string so that external provider can parse it properly. Otherwise you get an
# error. See this bug https://github.com/terraform-providers/terraform-provider-external/issues/23
program = [“bash”, “-c”, “az resource show --ids ${local.app_service_environment_id}/capacities/virtualip --query ‘{internalIpAddress: internalIpAddress}’ | jq -c”]
# Explicit dependency on the ASE ARM deployment because this command will fail
# if that resource isn’t built yet.
depends_on = [azurerm_template_deployment.ase]
}