Azure: Assign Roles via ARM Template to storage container

Question

I'm trying to assign the role "Storage Blob Data Contributor (Preview)" to a specific storage container via arm template. But I just can't figure out the correct syntax.

This is what I have:

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "principalId": {
            "type": "string",
            "metadata": {
                "description": "The principal to assign the role to"
            }
        },
        "builtInRoleType": {
            "type": "string",
            "allowedValues": [
                "Contributor",
                "Reader",
                "StorageBlobDataContributor"
            ],
            "metadata": {
                "description": "Built-in role to assign"
            }
        }
    },
    "variables": {
        "apiVersion": "2017-05-01",
        "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')]",
        "StorageBlobDataContributor": "[concat('/subscriptions/', subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/', 'ba92f5b4-2d11-453d-a403-e96b0029c9fe')]",
        "TestVariable": "[concat('STORAGEACCOUNTNAME','/Microsoft.Authorization/',guid(subscription().subscriptionId))]"
    },
    "resources": [
        {
            "type": "Microsoft.Storage/storageAccounts/providers/roleAssignments",
            "apiVersion": "[variables('apiVersion')]",
            "name": "[variables('TestVariable')]",
            "properties": {
                "roleDefinitionId": "[variables('Reader')]",
                "principalId": "[parameters('principalId')]"
            }
        },
        {
            "type": "Microsoft.Storage/storageAccounts/STORAGEACCOUNTNAME/blobServices/containers/blobCONTAINERNAME/providers/Microsoft.Authorization/roleAssignments",
            "apiVersion": "[variables('apiVersion')]",
            "name": "STORAGEACCOUNTNAME/blobServices/containers/default/blobCONTAINERNAME/Microsoft.Authorization/NEW-GUID",
            "properties": {
                "roleDefinitionId": "[variables('StorageBlobDataContributor')]",
                "principalId": "[parameters('principalId')]"
            }
        }
    ],
    "outputs": {}
}

I can attach the reader role to the storage account itself succesfully. But for the container I get the following error:

    new-AzResourceGroupDeployment : 09:21:24 - Error: Code=InvalidTemplate; Message=Deployment template validation failed: 'The template resource
'STORAGEACCOUNTNAME/blobServices/containers/CONTAINERNAME/Microsoft.Authorization/GUID' for type
'Microsoft.Storage/storageAccounts/STORAGEACCOUNTNAME/blobServices/default/containers/CONTAINERNAME/providers/Microsoft.Authorization/roleAssignments' at line '44' and column '9' has incorrect
segment lengths. A nested resource type must have identical number of segments as its resource name. A root resource type must have segment length one greater than its resource name. Please see
https://aka.ms/arm-template/#resources for usage details.'.

I have tried so many ways trying to attach the role, that I out of idea's. Can someone help me?

Answer 1

you need to construct something like this:

resourceId/Microsoft.Authorization/roleAssignments/NEW-GUID

and resourceId is normally being constructed as

type: provider/namespace
name: name

provider/namespace/name

for example, for subnet it would be (notice it takes 1 segment from each line in turn, except for the first one, first one is always 2 segments):

type: microsoft.network/virtualnetworks/subnets
name: vnetName/subnetName

microsoft.network/virtualnetworks/vnetName/subnets/subnetName

if that is even possible it would look like something like this:

"type": "Microsoft.Storage/storageAccounts/blobServices/containers/providers/roleAssignments",
"name": "STORAGEACCOUNTNAME/default/CONTAINERNAME/Microsoft.Authorization/NEW-GUID"

Microsoft.Storage/storageAccounts/STORAGEACCOUNTNAME/containers/CONTAINERNAME/providers/Microsoft.Authorization/roleAssignments/NEW-GUID

Answer 2

Made some little adjustments:

"type": "Microsoft.Storage/storageAccounts/blobServices/containers/providers/roleAssignments",
"name": "STORAGEACCOUNTNAME/default/CONTAINERNAME/Microsoft.Authorization/NEW-GUID"

This way I can assign roles on the container itself. Thanks 4c74356b41 for pointing me in the right direction