Azure ARM getting Values from variable - azure

Question

i have to create an ARM template an currently im stucked in using the variables with extendend values.
I define the variables
"variables": {
"NetWorkID": "[resourceId('Microsoft.Network/virtualNetworks', parameters('virtualNetworkName'))]",
}
And now i want to get the first subnet of the virtual Network.
I don´t know how to get the value.
i tested this but this doesn´t work:
"subnet": {
"id": "[variables('NetWorkID().subnet.ID')]"
}
Can i get a hint how to work with these variables?

Answer 1

usually you refer to subnets using the syntax bellow.
What you can do is pass the virtualNetworkName and subnet1Name as parameters and use the resourceid() expression.
"subnet": {
"id": "[resourceId(parameters('virtualNetworkResourceGroup'), 'Microsoft.Network/virtualNetworks/subnets', parameters('virtualNetworkName'), parameters('subnet1Name'))]"
}
Another way to do this, if you refer to the same subnet accross the arm template, is to build this resourceid in the variables instead of the resources and then use the variable in the resources properties.
Example:
"variables": {
"subnetId": "[resourceId(parameters('virtualNetworkResourceGroup'), 'Microsoft.Network/virtualNetworks/subnets', parameters('virtualNetworkName'), parameters('subnet1Name'))]"
},
"resources": [
{
"type": "Microsoft.Network/privateEndpoints",
"apiVersion": "xxxx",
"name": "xxxxx",
"location": "xxxxx",
"properties": {
"privateLinkServiceConnections": [
{
"name": "xxxxx",
"properties": {
"privateLinkServiceId": "xxxxx",
"groupIds": [
"blob"
]
}
}
],
**"subnet": {
"id": "[variables('subnetId')]"
}**,
"customDnsConfigs": [
{
"fqdn": "xxxxxx"
}
]
}
}
]
You can also try to list the existing subnets using the reference() function
"subnetId":"[reference(resourceId('Microsoft.Network/virtualNetworks', variables('vnetName')), '2022-01-01', 'Full').properties.subnets]"