Deploying Azure Firewall IP Group changes fails with conflict - azure

Question

I am attempting to deploy an Azure Firewall with a Policy, a Rule and a set of IPGroups. When I deploy the ARM templates to start everything works.. Later If I want to change something in one of the IPGroups, and I try to deploy that IPGroup change, the Azure Deployment fails with a Status: Conflict with message:
{
"status": "Failed",
"error": {
"code": "ResourceDeploymentFailure",
"message": "The resource operation completed with terminal provisioning state 'Failed'."
}
}
I've attempted to both manage the IPGroups distinctly in their own ARM Template, and place them in with the Azure Policy Rule Collection ARM Template with a DependsOn to see if deploying them all together would help, but either way we just get "Conflict".. I Guess I am wondering what is the appropriate way to update an IPGroup that is a part of a Firewall Network rule? If I can't simply update the IPGroup?
Here is an example of my full ARM Template for my Policy with the IPGroups..
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"firewallPolicyName": {
"defaultValue": "[concat('onelucki-fw-parent-policy', uniqueString(resourceGroup().id))]",
"type": "String"
},
"DevSubnets": {
"defaultValue": "DevSubnets",
"type": "String"
},
"AzureSubnets": {
"defaultValue": "AzureSubnets",
"type": "String"
}
},
"variables": {
"fwPolicyName": "[parameters('firewallPolicyName')]"
},
"resources": [
{
"type": "Microsoft.Network/ipGroups",
"apiVersion": "2020-05-01",
"name": "AzureSubnets",
"location": "centralus",
"tags": { "Zone": "MixedZones" },
"properties": {
"ipAddresses": [
"10.99.1.1"
]
}
},
{
"type": "Microsoft.Network/ipGroups",
"apiVersion": "2020-05-01",
"name": "DevSubnets",
"location": "centralus",
"tags": { "Zone": "Dev" },
"properties": {
"ipAddresses": [
"10.99.2.2"
]
}
},
{
"type": "Microsoft.Network/firewallPolicies",
"apiVersion": "2020-11-01",
"name": "[parameters('firewallPolicyName')]",
"location": "centralus",
"properties": {
"sku": {
"tier": "Standard"
},
"threatIntelMode": "Alert"
}
},
{
"type": "Microsoft.Network/firewallPolicies/ruleCollectionGroups",
"apiVersion": "2020-11-01",
"name": "[concat(parameters('firewallPolicyName'), '/DefaultNetworkRuleCollectionGroup')]",
"location": "westus",
"dependsOn": [
"[resourceId('Microsoft.Network/ipGroups', parameters('AzureSubnets'))]",
"[resourceId('Microsoft.Network/ipGroups', parameters('DevSubnets'))]",
"[resourceId('Microsoft.Network/firewallPolicies', parameters('firewallPolicyName'))]"
],
"properties": {
"priority": 200,
"ruleCollections": [
{
"ruleCollectionType": "FirewallPolicyFilterRuleCollection",
"action": {
"type": "Allow"
},
"rules": [
{
"ruleType": "NetworkRule",
"name": "DemoRule",
"ipProtocols": [
"TCP"
],
"sourceAddresses": [],
"sourceIpGroups": [
"/subscriptions/<subscriptionIDHere>/resourceGroups/onelucki-fw/providers/Microsoft.Network/ipGroups/DevSubnets"
],
"destinationAddresses": [],
"destinationIpGroups": [
"/subscriptions/<subscriptionIDHere>/resourceGroups/onelucki-fw/providers/Microsoft.Network/ipGroups/AzureSubnets"
],
"destinationFqdns": [],
"destinationPorts": [
"135",
"445"
]
}
],
"name": "DemoDeployRuleCollection",
"priority": 1300
}
]
}
}
]
}

Answer 1

IP groups need to be deployed one at a time. Also the firewall policy needs a depends on the IP groups being used despite it not having them listed.
The deploy of the IP groups seems to do some validation/update on the firewall policy during deploy.
Deploy nested resources in Azure using DependsOn