How to dynamically create Azure KeyVault reference in ARM template? - azure

Question

I'm using the following piece of code in my ARM template parameters file to retrieve the secret value from keyvault:
"parameters": {
"mailAccount": {
"reference": {
"keyVault": {
"id": "/subscriptions/GUID/resourceGroups/KeyVaultRG/providers/Microsoft.KeyVault/vaults/KeyVault"
},
"secretName": "mailAccount"
}
},
and in the template file:
"appSettings": [
{
"name": "mailAccount",
"value": "[parameters('mailAccount')]"
},
{
I'd like to know if it is possible to reference a KeyVault by its name using dynamically constructed object (i.e. not /subscriptions/GUID/resourceGroups/KeyVaultRG/providers/Microsoft.KeyVault/vaults/KeyVault but [resourceId(subscription().subscriptionId, resourcegroup().name, 'Microsoft.KeyVault/vaults', parameters('KeyVaultName'))]) or [resourceId('Microsoft.KeyVault/vaults', parameters('KeyVaultName'))] ?
In fact, the main objective is to be able to pass the different KeyVault names when deploying templates - where the similar values are stored.
The need to have several KeyVaults is justified by the resources (and cost) separation.
Now I see only validation errors saying ~ resourceId function cannot be used while referencing parameters.
I cannot use nested\linked templates (and output values).

Answer 1

What I am usually doing to avoid this limitation of the resourceId function is to define a variable with the value of the parameter, then using the variable instead in the resourceId function.
Example:
"parameters": {
"KeyVaultName": {
"type": "string",
"metadata": {
"description": "Key Vault Name"
}
}
},
"variables": {
"KeyVaultName": "[parameters('KeyVaultName')]"
}
Then when I am referencing the KeyVault resource I reference it using the variable like this:
"[resourceId('Microsoft.KeyVault/vaults', variables('KeyVaultName')]"