How to access/cast the module output to spefic object in bicep? - azure

Question

I am having below bicep which is returning keyvault. I like to access the properties/functions in keyvault in parent bicep. But not sure how to achieve when using it as a module.
I have keyvault.bicep
resource kv 'Microsoft.KeyVault/vaults#2019-09-01' existing = {
name: kvName
scope: resourceGroup(subscriptionId, kvResourceGroup )
}
output kv1 object=kv
I have parent.bicep (where keyvault.bicep is included as module)
module kv './keyvault.bicep' = {
name: 'get Secrets'
params: {
subscriptionId: subscriptionId
kvResourceGroup: resourceGroupName
kvName: keyVaultName
}
}
var pwd= kv.outputs.kv1.getSecret('key')
but getSecret method is unknown in parent bicep
Kindly suggest how to proceed?

Answer 1

The short answer is that is not supported.
In your parent.bicep file, kv is a module reference, not a resource. In order to correctly understand the parent-child resource hierarchy, Bicep requires a resource reference of the correct parent type in the parent property value.
Tho there is a proposal to simplify resource referencing:
https://github.com/Azure/bicep/issues/2246
Let say you have keyvault.bicep module that creates a key vault
resource kv 'Microsoft.KeyVault/vaults#2019-09-01' = {
name: kvName
...
}
output name string = kv.name
In the parent.bicep, you could get a reference to key vault like that:
module kvModule './keyvault.bicep' = {
name: 'key-vault-${keyVaultName}'
params: {
kvName: keyVaultName
...
}
}
resource kv 'Microsoft.KeyVault/vaults#2019-09-01' existing = {
name: kvModule.outputs.name
}
In you example, there are few things:
The key vault module just gets a reference to key vault so you don't really need a module, you could just reference the key vault directly in the parent.bicep file.
The getSecret function is a really specific function, you can only use it to pass secure parameter to another module:
Returns a secret from an Azure Key Vault. The getSecret function can only be called on a Microsoft.KeyVault/vaults resource. Use this function to pass a secret to a secure string parameter of a Bicep module. The function can be used only with a parameter that has the #secure() decorator.