Conditionally deploy a route table with subnet using ARM template - azure

Question

I am trying to conditionally deploy a route template when deploying a subnet resource using an ARM template, however, I am not able to do so using the if condition. Would anyone know the correct syntax or what am I doing wrong?
{
"$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"routeTableConfigurationObject": {
"type": "object",
"defaultValue": null
},
"vnetConfigurationObject": {
"type": "object"
},
"Tags": {
"type": "object"
}
},
"resources": [
{
"type": "Microsoft.Network/virtualNetworks/Subnets",
"name": "[concat(parameters('vnetConfigurationObject').name,'/',parameters('vnetConfigurationObject').subnets[copyIndex()].name)]",
"location": "[parameters('vnetConfigurationObject').location]",
"apiVersion": "2018-08-01",
"copy": {
"name": "vnet",
"count": "[length(parameters('vnetConfigurationObject').subnets)]",
"mode": "serial"
},
"properties": {
"addressPrefix": "[parameters('vnetConfigurationObject').subnets[copyIndex()].addressPrefix]",
"routeTable": "[if(empty('routeTableConfigurationObject'), json('null'), json(concat('{\"id\": \"', '/subscriptions/', parameters('routeTableConfigurationObject').subscriptionId, '/resourceGroups/', parameters('routeTableConfigurationObject').resourceGroupName, '/providers/Microsoft.Network/routeTables/', parameters('vnetConfigurationObject').subnets[copyIndex()].routeTable,'\"}')))]"
}
}
]
}

Answer 1

try this:
"variables": [
"copy": [
{
"name": "route",
"count": "[length(parameters('vnetConfigurationObject').subnets)]",
"input": {
"id": "[resourceId(parameters('routeTableConfigurationObject').subscriptionId, parameters('routeTableConfigurationObject').resourceGroupName, 'Microsoft.Network/routeTables', parameters('vnetConfigurationObject').subnets[copyIndex('route')].routeTable)]"
}
}
]
],
"resources": [
{
"type": "Microsoft.Network/virtualNetworks/Subnets",
"name": "[concat(parameters('vnetConfigurationObject').name,'/',parameters('vnetConfigurationObject').subnets[copyIndex()].name)]",
"location": "[parameters('vnetConfigurationObject').location]",
"apiVersion": "2018-08-01",
"copy": {
"name": "vnet",
"count": "[length(parameters('vnetConfigurationObject').subnets)]",
"mode": "serial"
},
"properties": {
"addressPrefix": "[parameters('vnetConfigurationObject').subnets[copyIndex()].addressPrefix]",
"routeTable": "[if(empty('routeTableConfigurationObject'), json('null'), variables('route')[copyIndex()])]"
}
}
]
I dont have time\ability to test it, but it should be pretty close