Azure Bicep nullability operators explained blog

safe-dereference.bicep

param parCnameRecord cnameType = {
  name: 'cname_bicepazure'
  ttl: 3600
  cnameRecord: {
    cname: 'copilot'
  }
}

resource resDnsZone 'Microsoft.Network/dnsZones@2023-07-01-preview' = {
  name: 'bicep.azure'
  location: 'global'

  resource resCnameRecord 'cname' = {
    name: parCnameRecord.name
    properties: {
      metadata: parCnameRecord.metadata
      TTL: parCnameRecord.ttl
      CNAMERecord: parCnameRecord.cnameRecord
    }
  }
}

type cnameType = {
  name: string
  metadata: object?
  ttl: int
  cnameRecord: {
    cname: string
  }?
}