Apply Azure RBAC to a resource using ARM

Question

Is there a way to apply RBAC rules at the resource level via ARM? I was able to follow this Microsoft guide to add a user/role at the resource group level, but not at the resource. In particular, I am trying to add a new reader role to AppInsights via ARM. However, when I adjust the scope, the template just fails with this error:

"error": {
"code": "InvalidCreateRoleAssignmentRequest",
"message": "The request to create role assignment '{guid}' is not valid. Role assignment scope '/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/Microsoft.Insights/components/{resourceGroupName}' must match the scope specified on the URI  '/subscriptions/{resourceGroupName}/resourcegroups/{resourceGroupName}'."
  }

I am left wondering what the scope variable is for if it cannot be changed. Is there some other place I should be modifying the scope to get this working?

Thanks in advance!

Answer 1

Microsoft has finally provided documentation explaining this:

https://docs.microsoft.com/en-us/azure/role-based-access-control/role-assignments-template#resource-scope

Answer 2

The key is to drop the scope property, and instead nest the role assignment under the desired resource by using Microsoft.FooResource/BarSubType/providers/roleAssignments as the type, and using the following format for the name: {resourceName}/Microsoft.Authorization/{uniqueRoleAssignmentGuid}. Note that the GUID should be stable but unique to this role assignment, one easy option is guid(subscription().subscriptionId, 'some-sub-identifier-if-you-wish').

Here is a template that shows you how to apply RBAC to a single resource, using a user-assigned managed identity defined in the same template:

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": { 
      "storageAccountName": { "type": "string" },
      "userAssignedIdentityName": { "type": "string" }
  },
  "variables": {
    "ContributorRoleDefinition": "[concat('/subscriptions/', subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/', 'b24988ac-6180-42a0-ab88-20f7382dd24c')]",
  },
  "resources": [
    {
      "type": "Microsoft.ManagedIdentity/userAssignedIdentities",
      "name": "[parameters('userAssignedIdentityName')]",
      "location": "[resourceGroup().location]",
      "apiVersion": "2018-11-30"
    },
    {
      "type": "Microsoft.Storage/storageAccounts",
      "name": "[parameters('storageAccountName')]",
      "location": "[resourceGroup().location]",
      "apiVersion": "2016-12-01",
      "sku": { "name": "Standard_LRS" },
      "kind": "Storage",
      "resources": [
          {
              "type": "Microsoft.Storage/storageAccounts/providers/roleAssignments",
              "apiVersion": "2017-05-01",
              "name": "[concat(parameters('storageAccountName'), '/Microsoft.Authorization/', guid(subscription().subscriptionId, 'foo'))]",
              "properties": {
                "roleDefinitionId": "[variables('ContributorRoleDefinition')]",
                "principalId": "[reference(parameters('userAssignedIdentityName'), '2018-11-30').principalId]"
              },
              "dependsOn": [
                  "[resourceId('Microsoft.Storage/storageAccounts', parameters('storageAccountName'))]",
                  "[resourceId('Microsoft.ManagedIdentity/userAssignedIdentities', parameters('userAssignedIdentityName'))]"
              ]
         }
      ]
    }
  ]
}

Source: https://www.henrybeen.nl/creating-an-authorization-rule-using-an-arm-template/

Answer 3

You apply RBAC rules at the resource level via an ARM and there is example template that applies RBAC rules at Azure VM here:

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "principalId": {
            "type": "string",
            "metadata": {
                "description": "Principal ID associated with the subscription ID"
            }
        },
        "virtualMachineName": {
            "type": "string",
            "metadata": {
                "description": "Name of the virtual machine"
            }
        },
        "builtInRoleType": {
            "type": "string",
            "metadata": {
                "description": "Built In Role Type for the Virtual Machine"
            },
            "allowedValues": [
                "Owner",
                "Contributor",
                "Reader",
                "Virtual Machine Contributor"
            ]
        },
        "guid": {
            "type": "string",
            "metadata": {
                "description": "A new GUID used to identify the role"
            }
        },
        "location": {
            "type": "string",
            "defaultValue": "[resourceGroup().location]",
            "metadata": {
                "description": "Location for all resources."
            }
        }
    },
    "variables": {
        "Owner": "[concat('/subscriptions/',subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/', '8e3af657-a8ff-443c-a75c-2fe8c4bcb635')]",
        "Contributor": "[concat('/subscriptions/',subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/', 'b24988ac-6180-42a0-ab88-20f7382dd24c')]",
        "Reader": "[concat('/subscriptions/',subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/', 'acdd72a7-3385-48ef-bd42-f606fba81ae7')]",
        "Virtual Machine Contributor": "[concat('/subscriptions/',subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/', 'd73bb868-a0df-4d4d-bd69-98a00b01fccb')]",
        "resourceName": "[concat(parameters('virtualMachineName'), '/Microsoft.Authorization/', parameters('guid'))]"
    },
    "resources": [
        {
            "type": "Microsoft.Compute/virtualMachines/providers/roleAssignments",
            "apiVersion": "2017-05-01",
            "name": "[variables('resourceName')]",
            "properties": {
                "roleDefinitionId": "[variables(parameters('builtInRoleType'))]",
                "principalId": "[parameters('principalId')]"
            }
        }
    ]
}

Hope this will help you.