Azure VM Scale Set CustomScriptExtension Failing

Question

I'm trying to create a windows Azure VM Scale Set that auto provisions a formatted attached data disk using the MS guide here: https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-attached-disks

No matter what I do I see to get this error:

9:14:16 PM - The deployment 'testvmss' failed with error(s). Showing 1 out of 1 error(s). Status | Message: VM has reported a failure when processing extension 'customScript'. Error message: "Invalid | Configuration - CommandToExecute is not specified in the configuration; it must be specified in either | the protected or public configuration section" More information on troubleshooting is available at | https://aka.ms/VMExtensionCSEWindowsTroubleshoot (Code:VMExtensionProvisioningError) CorrelationId: | 3294f49a-23f0-4634-aba0-3bb0e814659e

I've tried:

• moving the "commandToExecute" into the protected config area
• "typeHandlerVersion" numbers
• moving commandToExecute outside of the "settings" section
• using case corrected "CommandToExecute"
• Simplifying the powershell statement to "powershell echo test"
• Searching google for the error message, better/different examples, etc.

Here is the specific section of the ARM:

"extensionProfile": {
            "extensions": [
              {
                "name": "customScript",
                "properties": {
                  "publisher": "Microsoft.Compute",
                  "type": "CustomScriptExtension",
                  "typeHandlerVersion": "1.8",
                  "autoUpgradeMinorVersion": true,
                  "settings": {
                    "fileUris": ["https://raw.githubusercontent.com/Azure-Samples/compute-automation-configurations/master/prepare_vm_disks.ps1"],
                    "commandToExecute": "powershell.exe -ExecutionPolicy Unrestricted -File prepare_vm_disks.ps1"
                  }
                }
              }
            ]
          }

And for reference, here is the full ARM:

{
  "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "location": {
      "type": "string"
    },
    "virtualMachineScaleSetName": {
      "type": "string"
    },
    "virtualMachineScaleSetRG": {
      "type": "string"
    },
    "singlePlacementGroup": {
      "type": "string"
    },
    "instanceSize": {
      "type": "string"
    },
    "instanceCount": {
      "type": "string"
    },
    "upgradeMode": {
      "type": "string"
    },
    "priority": {
      "type": "string"
    },
    "enableAcceleratedNetworking": {
      "type": "string"
    },
    "subnetId": {
      "type": "string"
    },
    "osDiskType": {
      "type": "string"
    },
    "dataDisks": {
      "type": "array"
    },
    "addressPrefixes": {
      "type": "array"
    },
    "subnets": {
      "type": "array"
    },
    "virtualNetworkId": {
      "type": "string"
    },
    "virtualNetworkName": {
      "type": "string"
    },
    "networkSecurityGroups": {
      "type": "array"
    },
    "networkInterfaceConfigurations": {
      "type": "array"
    },
    "vmName": {
      "type": "string"
    },
    "scaleInPolicy": {
      "type": "object"
    },
    "overprovision": {
      "type": "bool"
    },
    "upgradePolicy": {
      "type": "string"
    },
    "adminUsername": {
      "type": "string"
    },
    "adminPassword": {
      "type": "secureString"
    },
    "platformFaultDomainCount": {
      "type": "string"
    }
  },
  "variables": {
    "storageApiVersion": "2019-04-01",
    "namingInfix": "[toLower(substring(concat(parameters('virtualMachineScaleSetName'), uniqueString(resourceGroup().id)), 0, 9))]"
  },
  "resources": [
    {
      "name": "[parameters('virtualNetworkName')]",
      "type": "Microsoft.Network/virtualNetworks",
      "apiVersion": "2019-09-01",
      "location": "[parameters('location')]",
      "properties": {
        "addressSpace": {
          "addressPrefixes": "[parameters('addressPrefixes')]"
        },
        "subnets": "[parameters('subnets')]"
      }
    },
    {
      "name": "[parameters('networkSecurityGroups')[copyIndex()].name]",
      "type": "Microsoft.Network/networkSecurityGroups",
      "apiVersion": "2019-02-01",
      "location": "[parameters('location')]",
      "properties": {
        "securityRules": "[parameters('networkSecurityGroups')[copyIndex()].rules]"
      },
      "copy": {
        "name": "networkSecurityGroups",
        "count": "[length(parameters('networkSecurityGroups'))]"
      }
    },
    {
      "name": "[parameters('virtualMachineScaleSetName')]",
      "type": "Microsoft.Compute/virtualMachineScaleSets",
      "apiVersion": "2019-12-01",
      "location": "[parameters('location')]",
      "dependsOn": [
        "[concat('Microsoft.Network/virtualNetworks/', parameters('virtualNetworkName'))]",
        "networkSecurityGroups",
        "[concat('Microsoft.Network/virtualNetworks/', parameters('virtualNetworkName'))]"
      ],
      "sku": {
        "name": "[parameters('instanceSize')]",
        "capacity": "[int(parameters('instanceCount'))]"
      },
      "properties": {
        "overprovision": "[parameters('overprovision')]",
        "upgradePolicy": {
          "mode": "[parameters('upgradePolicy')]"
        },
        "singlePlacementGroup": "[parameters('singlePlacementGroup')]",
        "virtualMachineProfile": {
          "storageProfile": {
            "osDisk": {
              "createOption": "fromImage",
              "caching": "ReadWrite",
              "managedDisk": {
                "storageAccountType": "[parameters('osDiskType')]"
              }
            },
            "imageReference": {
              "publisher": "MicrosoftWindowsServer",
              "offer": "WindowsServer",
              "sku": "2016-Datacenter",
              "version": "latest"
            },
            "copy": [
              {
                "name": "dataDisks",
                "count": "[length(parameters('dataDisks'))]",
                "input": {
                  "lun": "[parameters('dataDisks')[copyIndex('dataDisks')].lun]",
                  "createOption": "[parameters('dataDisks')[copyIndex('dataDisks')].createOption]",
                  "caching": "[parameters('dataDisks')[copyIndex('dataDisks')].caching]",
                  "writeAcceleratorEnabled": "[parameters('dataDisks')[copyIndex('dataDisks')].writeAcceleratorEnabled]",
                  "diskSizeGB": "[parameters('dataDisks')[copyIndex('dataDisks')].diskSizeGB]",
                  "managedDisk": {
                    "storageAccountType": "[parameters('dataDisks')[copyIndex('dataDisks')].storageAccountType]",
                    "diskEncryptionSet": "[parameters('dataDisks')[copyIndex('dataDisks')].diskEncryptionSet]"
                  },
                  "diskIOPSReadWrite": "[if(equals( parameters('dataDisks')[copyIndex('dataDisks')].diskIOPSReadWrite, -1), json('null'),parameters('dataDisks')[copyIndex('dataDisks')].diskIOPSReadWrite)]",
                  "diskMBpsReadWrite": "[if(equals( parameters('dataDisks')[copyIndex('dataDisks')].diskMBpsReadWrite, -1), json('null'),parameters('dataDisks')[copyIndex('dataDisks')].diskMBpsReadWrite)]"
                }
              }
            ]
          },
          "priority": "[parameters('priority')]",
          "networkProfile": {
            "copy": [
              {
                "name": "networkInterfaceConfigurations",
                "count": "[length(parameters('networkInterfaceConfigurations'))]",
                "input": {
                  "name": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].name]",
                  "properties": {
                    "primary": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].primary]",
                    "enableAcceleratedNetworking": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].enableAcceleratedNetworking]",
                    "ipConfigurations": [
                      {
                        "name": "[concat(parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].name, '-defaultIpConfiguration')]",
                        "properties": {
                          "subnet": {
                            "id": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].subnetId]"
                          },
                          "primary": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].primary]",
                          "applicationGatewayBackendAddressPools": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].applicationGatewayBackendAddressPools]",
                          "loadBalancerBackendAddressPools": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].loadBalancerBackendAddressPools]",
                          "loadBalancerInboundNatPools": "[parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].loadBalancerInboundNatPools]",
                          "publicIPAddressConfiguration": "[if( equals( parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].pipName, ''), json('null'), union(json(concat('{\"name\": \"', parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].pipName, '\"}'))\n                        ,json('{\"properties\": { \"idleTimeoutInMinutes\": 15}}')))]"
                        }
                      }
                    ],
                    "networkSecurityGroup": "[if( equals( parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].nsgId, ''), json('null'),json(concat('{\"id\": \"', parameters('networkInterfaceConfigurations')[copyIndex('networkInterfaceConfigurations')].nsgId, '\"}')))]"
                  }
                }
              }
            ]
          },
          "extensionProfile": {
            "extensions": [
              {
                "name": "customScript",
                "properties": {
                  "publisher": "Microsoft.Compute",
                  "type": "CustomScriptExtension",
                  "typeHandlerVersion": "1.8",
                  "autoUpgradeMinorVersion": true,
                  "settings": {
                    "fileUris": ["https://raw.githubusercontent.com/Azure-Samples/compute-automation-configurations/master/prepare_vm_disks.ps1"],
                    "commandToExecute": "powershell.exe -ExecutionPolicy Unrestricted -File prepare_vm_disks.ps1"
                  }
                }
              }
            ]
          },
          "osProfile": {
            "computerNamePrefix": "[variables('namingInfix')]",
            "adminUsername": "[parameters('adminUsername')]",
            "adminPassword": "[parameters('adminPassword')]",
            "windowsConfiguration": {
              "provisionVmAgent": true
            }
          }
        },
        "scaleInPolicy": "[parameters('scaleInPolicy')]",
        "platformFaultDomainCount": "[parameters('platformFaultDomainCount')]"
      }
    }
  ],
  "outputs": {
    "adminUsername": {
      "type": "string",
      "value": "[parameters('adminUsername')]"
    }
  }
}

Any help is greatly appreciated, thanks!

Answer 1

As the MS guide template, you need to include a dataDisks section in the storageProfile of the Microsoft.Compute/virtualMachineScaleSets resource(s) and deploy the template.

Here is a working template for your references:

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "vmSku": {
            "type": "string",
            "defaultValue": "Standard_A1_v2",
            "metadata": {
                "description": "Size of VMs in the VM Scale Set."
            }
        },
        "windowsOSVersion": {
            "type": "string",
            "defaultValue": "2016-Datacenter"
        },
        "vmssName": {
            "type": "string",
            "minLength": 3,
            "maxLength": 61
        },
        "instanceCount": {
            "type": "int",
            "defaultValue": 3,
            "minValue": 1,
            "maxValue": 100,
            "metadata": {
                "description": "Number of VM instances (100 or less)."
            }
        },
        "singlePlacementGroup": {
            "type": "bool",
            "defaultValue": true
        },
        "adminUsername": {
            "type": "string",
            "defaultValue": "vmssadmin"
        },
        "adminPassword": {
            "type": "securestring"
        },
        "location": {
            "type": "string",
            "defaultValue": "[resourceGroup().location]"
        },
        "platformFaultDomainCount": {
            "type": "int",
            "defaultValue": 1
        }
    },
    "variables": {
        "namingInfix": "[toLower(substring(concat(parameters('vmssName'), uniqueString(resourceGroup().id)), 0, 9))]",
        "longNamingInfix": "[toLower(parameters('vmssName'))]",
        "addressPrefix": "10.0.0.0/16",
        "subnetPrefix": "10.0.0.0/24",
        "virtualNetworkName": "[concat(variables('namingInfix'), 'vnet')]",
        "publicIPAddressName": "[concat(variables('namingInfix'), 'pip')]",
        "subnetName": "[concat(variables('namingInfix'), 'subnet')]",
        "loadBalancerName": "[concat(variables('namingInfix'), 'lb')]",
        "publicIPAddressID": "[resourceId('Microsoft.Network/publicIPAddresses',variables('publicIPAddressName'))]",
        "lbProbeID": "[resourceId('Microsoft.Network/loadBalancers/probes',variables('loadBalancerName'), 'tcpProbe')]",
        "natPoolName": "[concat(variables('namingInfix'), 'natpool')]",
        "bePoolName": "[concat(variables('namingInfix'), 'bepool')]",
        "lbPoolID": "[resourceId('Microsoft.Network/loadBalancers/backendAddressPools',variables('loadBalancerName'),variables('bePoolName'))]",
        "natStartPort": 50000,
        "natEndPort": 50119,
        "natBackendPort": 3389,
        "nicName": "[concat(variables('namingInfix'), 'nic')]",
        "ipConfigName": "[concat(variables('namingInfix'), 'ipconfig')]",
        "frontEndIPConfigID": "[resourceId('Microsoft.Network/loadBalancers/frontendIPConfigurations',variables('loadBalancerName'),'loadBalancerFrontEnd')]",
        "osType": {
            "publisher": "MicrosoftWindowsServer",
            "offer": "WindowsServer",
            "sku": "[parameters('windowsOSVersion')]",
            "version": "latest"
        },
        "imageReference": "[variables('osType')]"
    },
    "resources": [
        {
            "type": "Microsoft.Network/loadBalancers",
            "apiVersion": "2020-06-01",
            "name": "[variables('loadBalancerName')]",
            "location": "[parameters('location')]",
            "dependsOn": [
                "[resourceId('Microsoft.Network/publicIPAddresses', variables('publicIPAddressName'))]"
            ],
            "properties": {
                "frontendIPConfigurations": [
                    {
                        "name": "LoadBalancerFrontEnd",
                        "properties": {
                            "publicIPAddress": {
                                "id": "[variables('publicIPAddressID')]"
                            }
                        }
                    }
                ],
                "backendAddressPools": [
                    {
                        "name": "[variables('bePoolName')]"
                    }
                ],
                "inboundNatPools": [
                    {
                        "name": "[variables('natPoolName')]",
                        "properties": {
                            "frontendIPConfiguration": {
                                "id": "[variables('frontEndIPConfigID')]"
                            },
                            "protocol": "Tcp",
                            "frontendPortRangeStart": "[variables('natStartPort')]",
                            "frontendPortRangeEnd": "[variables('natEndPort')]",
                            "backendPort": "[variables('natBackendPort')]"
                        }
                    }
                ],
                "loadBalancingRules": [
                    {
                        "name": "LBRule",
                        "properties": {
                            "frontendIPConfiguration": {
                                "id": "[variables('frontEndIPConfigID')]"
                            },
                            "backendAddressPool": {
                                "id": "[variables('lbPoolID')]"
                            },
                            "protocol": "Tcp",
                            "frontendPort": 80,
                            "backendPort": 80,
                            "enableFloatingIP": false,
                            "idleTimeoutInMinutes": 5,
                            "probe": {
                                "id": "[variables('lbProbeID')]"
                            }
                        }
                    }
                ],
                "probes": [
                    {
                        "name": "tcpProbe",
                        "properties": {
                            "protocol": "Tcp",
                            "port": 80,
                            "intervalInSeconds": 5,
                            "numberOfProbes": 2
                        }
                    }
                ]
            }
        },
        {
            "type": "Microsoft.Compute/virtualMachineScaleSets",
            "apiVersion": "2020-06-01",
            "name": "[variables('namingInfix')]",
            "location": "[parameters('location')]",
            "sku": {
                "name": "[parameters('vmSku')]",
                "tier": "Standard",
                "capacity": "[parameters('instanceCount')]"
            },
            "dependsOn": [
                "[resourceId('Microsoft.Network/loadBalancers', variables('loadBalancerName'))]",
                "[resourceId('Microsoft.Network/virtualNetworks', variables('virtualNetworkName'))]"
            ],
            "properties": {
                "overprovision": true,
                "upgradePolicy": {
                    "mode": "Automatic"
                },
                "singlePlacementGroup": "[parameters('singlePlacementGroup')]",
                "platformFaultDomainCount": "[parameters('platformFaultDomainCount')]",
                "virtualMachineProfile": {
                    "storageProfile": {
                        "osDisk": {
                            "caching": "ReadWrite",
                            "createOption": "FromImage"
                        },
                        "dataDisks": [
                            {
                            "diskSizeGB": 128,
                            "lun": 0,
                            "createOption": "Empty"
                            }
                        ],
                        "imageReference": "[variables('imageReference')]"
                    },
                    "osProfile": {
                        "computerNamePrefix": "[variables('namingInfix')]",
                        "adminUsername": "[parameters('adminUsername')]",
                        "adminPassword": "[parameters('adminPassword')]"
                    },
                    "networkProfile": {
                        "networkInterfaceConfigurations": [
                            {
                                "name": "[variables('nicName')]",
                                "properties": {
                                    "primary": true,
                                    "ipConfigurations": [
                                        {
                                            "name": "[variables('ipConfigName')]",
                                            "properties": {
                                                "subnet": {
                                                    "id": "[resourceId('Microsoft.Network/virtualNetworks/subnets', variables('virtualNetworkName'), variables('subnetName'))]"
                                                },
                                                "loadBalancerBackendAddressPools": [
                                                    {
                                                        "id": "[variables('lbPoolID')]"
                                                    }
                                                ],
                                                "loadBalancerInboundNatPools": [
                                                    {
                                                        "id": "[resourceId('Microsoft.Network/loadBalancers/inboundNatPools', variables('loadBalancerName'),  variables('natPoolName'))]"
                                                    }
                                                ]
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "extensionProfile": {
                        "extensions": [

{
    "name": "customScript",
    "properties": {
        "publisher": "Microsoft.Compute",
        "type": "CustomScriptExtension",
        "typeHandlerVersion": "1.8",
        "autoUpgradeMinorVersion": true,
        "settings": {
        "fileUris": [
            "https://raw.githubusercontent.com/Azure-Samples/compute-automation-configurations/master/prepare_vm_disks.ps1"
        ],
        "commandToExecute": "powershell -ExecutionPolicy Unrestricted -File prepare_vm_disks.ps1"
        }
    }
}


                        ]
                    }
                }
            }
        },
        {
            "type": "Microsoft.Network/publicIPAddresses",
            "apiVersion": "2020-06-01",
            "name": "[variables('publicIPAddressName')]",
            "location": "[parameters('location')]",
            "properties": {
                "publicIPAllocationMethod": "Static",
                "dnsSettings": {
                    "domainNameLabel": "[variables('longNamingInfix')]"
                }
            }
        },
        {
            "type": "Microsoft.Network/virtualNetworks",
            "apiVersion": "2020-06-01",
            "name": "[variables('virtualNetworkName')]",
            "location": "[parameters('location')]",
            "properties": {
                "addressSpace": {
                    "addressPrefixes": [
                        "[variables('addressPrefix')]"
                    ]
                },
                "subnets": [
                    {
                        "name": "[variables('subnetName')]",
                        "properties": {
                            "addressPrefix": "[variables('subnetPrefix')]"
                        }
                    }
                ]
            }
        }
      
    ],
    "outputs": {}
}

If you want to create multiple data disks with the copy function, you can add it like this

            "storageProfile": {
                "osDisk": {
                    "caching": "ReadWrite",
                    "createOption": "FromImage"
                },
  "copy": [
    {
      "name": "dataDisks",
      "count": "[parameters('numberOfDataDisks')]",
      "input": {
        "diskSizeGB": 1023,
        "lun": "[copyIndex('dataDisks')]",
        "createOption": "Empty"
      }
    }
  ],

After my validation, after the above deployment finishs, you need to initialize the disk in each instance, then you could get the expected result.

Reference: https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/tutorial-use-disks-powershell#prepare-the-data-disks

Answer 2

I had the same issue with VMSS Managed Disk and Service Fabric, because there is a problem with the last commit (from last September) - Here you can find an open issue about it.

Until this issue would be solved you can still use the script extension with link to previous version as I did: https://raw.githubusercontent.com/Azure-Samples/compute-automation-configurations/fdc643759c9aa7e9259da10575e67dc1368e4e9f/prepare_vm_disks.ps1

Add this script extension to the extensionProfile of the virtualMachineProfile of the scale set:

{
    "name": "customScript",
    "properties": {
        "publisher": "Microsoft.Compute",
        "type": "CustomScriptExtension",
        "typeHandlerVersion": "1.8",
        "autoUpgradeMinorVersion": true,
        "settings": {
        "fileUris": [
            "https://https://raw.githubusercontent.com/Azure-Samples/compute-automation-configurations/fdc643759c9aa7e9259da10575e67dc1368e4e9f/prepare_vm_disks.ps1"
        ],
        "commandToExecute": "powershell -ExecutionPolicy Unrestricted -File prepare_vm_disks.ps1"
        }
    }
}