Azure Resource Manager Template: How to get connection string for a resource in a different ResourceGroup?

Question

I want to deploy a AzureKeyVault that contains AzureStorageAccount connection string from another resource group. I know you can do this if AzureKeyVault and AzureStorageAccount are in the same resource group, like in the following:

"resources": [
    {
      "type": "Microsoft.KeyVault/vaults/secrets",
      "name": "secretName",
      "properties": {
        "value": "[concat('DefaultEndpointsProtocol=https;EndpointSuffix=core.windows.net;AccountName=', 'StorageAccountName', ';AccountKey=', first(listKeys(resourceId('Microsoft.Storage/storageAccounts', 'StorageAccountName'), variables('storageApiVersion')).keys).value)]"
      },
      "dependsOn": []
    },
    {
      "type": "Microsoft.Storage/storageAccounts",
      "name": "StorageAccountName",
      ...
    },
    {
        "type": "Microsoft.KeyVault/vaults",
        "name": "KeyVaultName",
        ...
    }
  ]

My question is how can an change this to get the connection string from a different resource group that has already been deployed?

Answer 1

use the built-in functionality of the resourceId() function:

resourceId(%different_rg_name%, 'Microsoft.Storage/storageAccounts', 'StorageAccountName')

https://learn.microsoft.com/en-us/azure/azure-resource-manager/resource-group-template-functions-resource#resourceid