Can I loop over properties in ARM templates?
I have an ARM template where I set up a load balancer and I want to add a number of port openings by adding rules and probes to the LB.
This is the template I have so far:
{
"type": "Microsoft.Network/loadBalancers",
"name": "LB-front",
"apiVersion": "2016-03-30",
"location": "westeurope",
"tags": { },
"properties": {
"frontendIPConfigurations": [
{
"name": "LoadBalancerIPConfig",
"properties": {
"privateIPAllocationMethod": "Dynamic",
"publicIPAddress": {
"id": "[resourceId('Microsoft.Network/publicIPAddresses', parameters('publicIPAddresses_lbipdev_0_name'))]"
}
}
}
],
"backendAddressPools": [
{
"name": "LoadBalancerBEAddressPool"
}
],
"loadBalancingRules": [
{
"name": "AppPortLBRule1",
"properties": {
"frontendIPConfiguration": {
"id": "[parameters('loadBalancers_LB_dev_id_6')]"
},
"frontendPort": 80,
"backendPort": 80,
"enableFloatingIP": false,
"idleTimeoutInMinutes": 5,
"protocol": "Tcp",
"loadDistribution": "Default",
"backendAddressPool": {
"id": "[parameters('loadBalancers_LB_dev_id_7')]"
},
"probe": {
"id": "[parameters('loadBalancers_LB_dev_id_8')]"
}
}
},
{
"name": "AppPortLBRule2",
"properties": {
"frontendIPConfiguration": {
"id": "[parameters('loadBalancers_LB_dev_id_9')]"
},
"frontendPort": 81,
"backendPort": 81,
"enableFloatingIP": false,
"idleTimeoutInMinutes": 5,
"protocol": "Tcp",
"loadDistribution": "Default",
"backendAddressPool": {
"id": "[parameters('loadBalancers_LB_dev_id_10')]"
},
"probe": {
"id": "[parameters('loadBalancers_LB_dev_id_11')]"
}
}
},
{
"name": "AppPortLBRule3",
"properties": {
"frontendIPConfiguration": {
"id": "[parameters('loadBalancers_LB_dev_id_12')]"
},
"frontendPort": 82,
"backendPort": 82,
"enableFloatingIP": false,
"idleTimeoutInMinutes": 5,
"protocol": "Tcp",
"loadDistribution": "Default",
"backendAddressPool": {
"id": "[parameters('loadBalancers_LB_dev_id_13')]"
},
"probe": {
"id": "[parameters('loadBalancers_LB_dev_id_14')]"
}
}
}
],
"probes": [
{
"name": "AppPortProbe1",
"properties": {
"protocol": "Tcp",
"port": 80,
"intervalInSeconds": 5,
"numberOfProbes": 2
}
},
{
"name": "AppPortProbe2",
"properties": {
"protocol": "Tcp",
"port": 81,
"intervalInSeconds": 5,
"numberOfProbes": 2
}
},
{
"name": "AppPortProbe3",
"properties": {
"protocol": "Tcp",
"port": 82,
"intervalInSeconds": 5,
"numberOfProbes": 2
}
}
],
"inboundNatRules": [],
"outboundNatRules": [],
"inboundNatPools": []
},
"resources": [],
"dependsOn": [
"[resourceId('Microsoft.Network/publicIPAddresses', parameters('publicIPAddresses_lbipdev_1_name'))]"
]
},
(some details omitted)
What I would like to do is to have an array of the port numbers I want to create rules and probes for and loop over those instead of explicitly having to write each rule and probe as a property for the resource.
Basically I would like a parameter or variable in my template like this:
"ports": [ 80, 81, 82, ...]
and that I could loop over this similar to this: https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-group-create-multiple.
Answer
Indeed you can! Copy does work with properties!
Create a parameter or variable like this (this example will use parameter array):
"lbRules": {
"type": "array",
"defaultValue": [
{
"name": "httpPort",
"frontendPort": "80",
"backendPort": "80",
"protocol": "tcp"
},
{
"name": "customAppPort",
"frontendPort": "8080",
"backendPort": "8888",
"protocol": "tcp"
},
{
"name": "httpsPort",
"frontendPort": "443",
"backendPort": "443",
"protocol": "tcp"
}
]
}
Use this parameter in the Loadbalancer resource using copy like this that will create that many probes and rules that you defined in your parameter array:
{
"apiVersion": "[variables('lbApiVersion')]",
"type": "Microsoft.Network/loadBalancers",
"name": "[parameters('myLoadBalancer')]",
"location": "[parameters('computeLocation')]",
"dependsOn": [
"[concat('Microsoft.Network/publicIPAddresses/',concat(parameters('lbIPName'),'-','0'))]"
],
"properties": {
"frontendIPConfigurations": [
{
"name": "LoadBalancerIPConfig",
"properties": {
"publicIPAddress": {
"id": "[resourceId('Microsoft.Network/publicIPAddresses',concat(parameters('lbIPName'),'-','0'))]"
}
}
}
],
"backendAddressPools": [
{
"name": "LoadBalancerBEAddressPool",
"properties": {}
}
],
"copy": [
{
"name": "probes",
"count": "[length(parameters('lbRules'))]",
"input": {
"name": "[concat(parameters('lbRules')[copyIndex('probes')].name,'Probe')]",
"properties": {
"intervalInSeconds": 5,
"numberOfProbes": 2,
"port": "[parameters('lbRules')[copyIndex('probes')].backendPort]",
"protocol": "[parameters('lbRules')[copyIndex('probes')].protocol]"
}
}
},
{
"name": "loadBalancingRules",
"count": "[length(parameters('lbRules'))]",
"input": {
"name": "[parameters('lbRules')[copyIndex('loadBalancingRules')].name]",
"properties": {
"frontendIPConfiguration": {
"id": "[concat(resourceId('Microsoft.Network/loadBalancers', parameters('myLoadBalancer')),'/frontendIPConfigurations/LoadBalancerIPConfig')]"
},
"frontendport": "[parameters('lbRules')[copyIndex('loadBalancingRules')].frontendport]",
"backendport": "[parameters('lbRules')[copyIndex('loadBalancingRules')].backendport]",
"enableFloatingIP": false,
"idleTimeoutInMinutes": "5",
"protocol": "[parameters('lbRules')[copyIndex('loadBalancingRules')].protocol]",
"backendAddressPool": {
"id": "[concat(resourceId('Microsoft.Network/loadBalancers', parameters('myLoadBalancer')),'/backendAddressPools/LoadBalancerBEAddressPool')]"
},
"probe": {
"id": "[concat(variables('lbID0'),'/probes/', parameters('lbRules')[copyIndex('loadBalancingRules')].name,'Probe')]"
}
}
}
}
],
"inboundNatPools": []
},
}
}
More info can be found here: https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-group-create-multiple#property-iteration