Error getting keys from Azure Storage Account with listkeys(...) method with Bicep syntax - azure-resource-manager

Question

I have a Bicep template to create an Azure Storage Account
#description('the name of the storage account')
param name string
#description('the alias of the storage account')
param shortName string
#description('tags')
param tags object
#description('the name of the key vault resource where place output secrets')
param keyVaultName string
resource storageAccount 'Microsoft.Storage/storageAccounts#2022-09-01' = {
name: name
location: resourceGroup().location
sku: {
name: 'Standard_LRS'
tier: 'Standard'
}
kind: 'StorageV2'
tags: union(tags, {
type: 'storage-account'
})
}
Then, I need to get the keys
var keys = listkeys(storageAccount.id, storageAccount.apiVersion)
output keyObject object = keys[0]
output KeyValue string = keys[0].value
But everytime that I runs the template, I receive these errors:
{
"code": "DeploymentOutputEvaluationFailed",
"message": "Unable to evaluate template outputs: 'keyObject,keyValue'. Please see error details and deployment operations. Please see https://aka.ms/arm-common-errors for usage details.",
"details": [
{
"code": "DeploymentOutputEvaluationFailed",
"target": "keyObject",
"message": "The template output 'keyObject' is not valid: The language expression property '0' can't be evaluated, property name must be a string.."
},
{
"code": "DeploymentOutputEvaluationFailed",
"target": "keyValue",
"message": "The template output 'keyValue' is not valid: The language expression property '0' can't be evaluated, property name must be a string.."
}
]
}
The purpose of get keys is to save it into Azure Key Vault by using KeyValue var from previous step
resource keyVault 'Microsoft.KeyVault/vaults#2022-07-01' existing = {
name: keyVaultName
}
resource secret 'Microsoft.KeyVault/vaults/secrets#2022-07-01' = {
parent: keyVault
name: secretName
properties: {
value: KeyValue
contentType: 'plain/text'
}
}
So..
What's wrong with listKeys(...) method?

Answer 1

By following this tweet https://twitter.com/adotfrank/status/1341084692100108288?s=46&t=sWx0hvS0sS47llWLlbWZTw I found an alternative method to get keys.
Just referencing to a storage account object and use the method listKeys()
resource storageAccount 'Microsoft.Storage/storageAccounts#2022-09-01' = {
name: name
location: resourceGroup().location
sku: {
name: 'Standard_LRS'
tier: 'Standard'
}
kind: 'StorageV2'
tags: union(tags, {
type: 'storage-account'
})
}
var storageAccountKeys = storageAccount.listKeys()
Then, I can access to primary or secondary key with storageAccountKeys.keys[0].value
This fix solve my issue.