ServiceCidr not accepting non-default values in arm templates

[Tyler-Angell]

What happened: Attempted to deploy an aks cluster via an arm template and received a ServiceCidrOverlapExistingSubnetsCidr error code with the following message: The specified service CIDR 10.0.0.0/16 is conflicted with an existing subnet CIDR 10.0.0.0/20. However, as shown below my template passes in 10.4.0.0/16. What am I missing? Why doesn't the 'specified' value match the value I passed my template?

Parameters:

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#",
  "contentVersion": "1.0.0.0",
  "paths": [],
  "parameters": {
    "clusterName": {
      "value": "k8s-dt-su-ta-scus-01"
    },
    "agentPools":{
      "value": [
        //
          {
            "name": "nodepool01",
            "count": 2,
            "sku": "Standard_DS2_v2",
            "vnet": "vnet-dt-su-ta-scus-01",
            "subnet": "Kubernetes",
          },
        //
      ]
    },
    "networkProfile":{
      "value": {
        "loadBalancerSku": "Standard",
        "networkPlugin": "Azure",
        "networkPolicy": "Azure",
        "serviceCidr": "10.4.0.0/16",
        "dnsServiceIP": "10.4.0.10",
        "dockerBridgeCidr": "172.17.0.1/16"
      }
    },
    "enablePrivateCluster":{
      "value": "True"
    },
    "containerRegistry":{
      "value": "tyangell"
    },
    "containerRegistryResourceGroup":{
      "value": "k8s-learning"
    }
  }
}

Template:

{
  "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "clusterName": {
      "type": "string"
    },
    "agentPools": {
      "type": "array"
    },
    "networkProfile": {
      "type": "object"
    },
    "enablePrivateCluster": {
      "type": "string"
    },
    "containerRegistry": {
      "type": "string"
    },
    "containerRegistryResourceGroup": {
      "type": "string"
    },
  },
  "variables": {},
  "resources": [
    {
      "apiVersion": "2020-09-01",
      "dependsOn": [],
      "type": "Microsoft.ContainerService/managedClusters",
      "location": "[resourceGroup().location]",
      "name": "[parameters('clusterName')]",
      "properties": {
        "kubernetesVersion": "1.18.10",
        "enableRBAC": true,
        "dnsPrefix": "[parameters('clusterName')]",
        "networkProfile": "[parameters('networkProfile')]",
        "apiServerAccessProfile": {
          "enablePrivateCluster": "[bool(parameters('enablePrivateCluster'))]"
        },
        "addonProfiles": {
          "httpApplicationRouting": {
            "enabled": false
          },
          "azurePolicy": {
            "enabled": true
          }
        },
        "copy": [
          {
            "name": "agentPoolProfiles",
            "count": "[length(parameters('agentPools'))]",
            "input": {
              "name": "[parameters('agentPools')[copyIndex('agentPoolProfiles')].name]",
              "count": "[parameters('agentPools')[copyIndex('agentPoolProfiles')].count]",
              "vmSize": "[parameters('agentPools')[copyIndex('agentPoolProfiles')].sku]",
              "osType": "Linux",
              "osDiskType": "Managed",
              "type": "VirtualMachineScaleSets",
              "mode": "System",
              "vnetSubnetID": "[resourceId('Microsoft.Network/virtualNetworks/subnets', parameters('agentPools')[copyIndex('agentPoolProfiles')].vnet, parameters('agentPools')[copyIndex('agentPoolProfiles')].subnet)]"
            }
          }
        ]
      },
      "tags": {},
      "identity": {
        "type": "SystemAssigned"
      }
    }
  ],
  "outputs": {
    "controlPlaneFQDN": {
      "type": "string",
      "value": "[reference(concat('Microsoft.ContainerService/managedClusters/', parameters('clusterName'))).privateFQDN]"
    }
  }
}

Deployment CorrelationId: 2566c123-bb0e-4176-903a-60d8bbfb122e

[ghost]

Hi Tyler-Angell, AKS bot here :wave: Thank you for posting on the AKS Repo, I'll do my best to get a kind human from the AKS team to assist you.

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[Tyler-Angell]

It turns out that the accepted values for the below are case sensitive. Fixing the casing allowed the template to successfully deploy. I am unblocked, but this still feels like a bug (both casing requirement and error message discoverability) so I'm leaving this opened to be triaged appropriately.

Before

"loadBalancerSku": "Standard",
"networkPlugin": "Azure",
"networkPolicy": "Azure",

After

"loadBalancerSku": "standard",
"networkPlugin": "azure",
"networkPolicy": "azure",

[yangl900]

thanks for reporting @Tyler-Angell . It does look like an bug we have. The message was very confusing, sorry about that.