Type casting in bicep

Question

I'm playing around with bicep and don't get how I can cast a param to i.e. Microsoft.Network/virtualNetworks

Example:

param vnet object
param name string
param addressPrefix string
param portfilter_mgmt_id string
resource Subnet 'Microsoft.Network/virtualNetworks/subnets@2021-02-01' = {
parent: vnet
name: name
properties: {
addressPrefix: addressPrefix
networkSecurityGroup: {
id: portfilter_mgmt_id
    }
  }
}

vnet is typeof object and must be casted to Microsoft.Network/virtualNetworks somehow - Any idea?

Answer 1

To complement @jean-marie answer. You can have more information about referencing existing resources in your Bicep deployment with this Microsoft Q&A Video:

https://www.youtube.com/watch?v=H1g_pj1uo5E

Answer 2

@Tom Welcome to Microsoft Q & A Community Forum. From the example you have provided , seems you are trying to define child resource outside of the parent resource.

Below is sample example where you use the resource keyword to define a resource to deploy. Your resource declaration includes a symbolic name for the resource. You'll use this symbolic name in other parts of the Bicep file to get a value from the resource.

resource vnet 'Microsoft.Network/virtualNetworks@2020-06-01' = {  
  name: 'virtualNetworkName'  
  location: 'eastus'  
  properties: {  
    addressSpace: {  
      addressPrefixes: [  
        '10.0.0.0/16'  
      ]  
    }  
  }  
}  
  
resource subnet1Name 'Microsoft.Network/virtualNetworks/subnets@2021-02-01' = {  
  name: 'default'  
  parent: vnet  
   properties: {  
          addressPrefix: '10.0.1.0/24'  
  
}  
}  

Answer 3

Hello @Tom , I'm making a few assumptions here, but if you are not able to as in the sample suggested by SwathiDhanwada-MSFT created both vnet and the child subnet at once, here's an alternative:

@description('Rather than using the vnet object, pass the vnet name and retrieve it via the vnet name')  
param vnetName string  
param name string  
param addressPrefix string  
param portfilter_mgmt_id string  
  
// Assuming that the vnet was created elsewhere, you can reference it by using the existing keyword  
resource vnet 'Microsoft.Network/virtualNetworks@2021-05-01' existing = {  
  name: vnetName  
}  
  
resource subnet 'Microsoft.Network/virtualNetworks/subnets@2021-02-01' = {  
  parent: vnet // use the symbolic name of the vnet declaration above  
  name: name  
  properties: {  
    addressPrefix: addressPrefix  
    networkSecurityGroup: {  
      id: portfilter_mgmt_id  
    }  
  }  
}