Ternary operator on module scope

[TacticalNuclearSpud]

Is it possible to use the ternary operator on the scope tag of a bicep module? The template I have validates fine but fails on deployment.

I'd like to be able to specify if a new resource group is required, if it is, deploy it and subsequently deploy the module resources into it, but, if not, take the name of an existing resource group and deploy the resources to that.

I'm relatively new to bicep and really struggling to get my head round this one.

Current main.bicep

targetScope = 'subscription'

@description('The Azure region into which the resources should be deployed. Defaults to the location of the resource group')
param location string = 'uksouth'

@description('The customer name, default for testing')
param customerName string = 'ExampleCustomer'

param newResourceGroupRequired bool = false
// ignore below if above is set to true
var existingResourceGroupName = 'rg-demo-existing'

// Create new resource group if required
resource newResourceGroup 'Microsoft.Resources/resourceGroups@2022-09-01' = if (newResourceGroupRequired) {
  name: 'rg-demo-${customerName}-new'
  location: location
}

// Use existing resource group if required
resource existingResourceGroup 'Microsoft.Resources/resourceGroups@2022-09-01' existing = {
  name: existingResourceGroupName
}

module storage 'modules/storage.bicep' = {
  scope: newResourceGroupRequired ? newResourceGroup : existingResourceGroup
  name: 'storage'
  params: {
    location: location
    storageAccountName: 'satestmikeb56'
  }
}

The deployment fails with

New-AzDeployment: 17:08:19 - The deployment 'deployment' failed with error(s). Showing 2 out of 2 error(s).
Status Message: The Resource 'Microsoft.Storage/storageAccounts/satestmikeb56' under resource group '<null>' was not found. For more details please go to https://aka.ms/ARMResourceNotFoundFix `(Code:ResourceNotFound)

If I leave the newResourceGroupRequired value set as false and set the scope on the module declaration to reference the newResourceGroup resource directly, as below, it deploys fine.

module storage 'modules/storage.bicep' = {
  scope: newResourceGroup
  name: 'storage'
  params: {
    location: location
    storageAccountName: 'satestmikeb56'
  }
}

Same if I change the bool to true and set the scope to existingResourceGroup, the storage module deploys without issue.

If used the ternary operator successfully on other parameters recently but I'm unable to do so in this case. Is there a another/better way to accomplish this?

Any help would be greatly appreciated!

[brwilkinson]

Hi @TacticalNuclearSpud

Thank you for reporting this, I believe it should work, so I have converted this discussion into an issue, which you can track:

• Ternary operator on module scope #10419

I will mark this as answered and please comment or follow the open. issue.

[brwilkinson]

Added workaround on this comment:

• Ternary operator on module scope #10419 (comment)