{
  "variables": {
    "client_id": "{{env `ARM_CLIENT_ID`}}",
    "client_secret": "{{env `ARM_CLIENT_SECRET`}}",
    "resource_group": "{{env `ARM_RESOURCE_GROUP`}}",
    "storage_account": "{{env `ARM_STORAGE_ACCOUNT`}}",
    "subscription_id": "{{env `ARM_SUBSCRIPTION_ID`}}"
  },
  "builders": [
    {
      "type": "azure-arm",
        
      "client_id": "{{user `client_id`}}",
      "client_secret": "{{user `client_secret`}}",
      "resource_group_name": "{{user `resource_group`}}",
      "storage_account": "{{user `storage_account`}}",
      "subscription_id": "{{user `subscription_id`}}",

      "capture_container_name": "images",
      "capture_name_prefix": "packer",

      "os_type": "Windows",
      "image_url": "https://my-storage-account.blob.core.windows.net/path/to/your/custom/image.vhd",

      "azure_tags": {
        "dept": "engineering",
        "task": "image deployment"
      },

      "location": "West US",
      "vm_size": "Standard_A2"
    }
  ],
  "provisioners": [{
    "type": "powershell",
    "inline": [
      "if( Test-Path $Env:SystemRoot\\windows\\system32\\Sysprep\\unattend.xml ){ rm $Env:SystemRoot\\windows\\system32\\Sysprep\\unattend.xml -Force}",
      "& $Env:SystemRoot\\System32\\Sysprep\\Sysprep.exe /oobe /generalize /shutdown /quiet"
    ]
  }]
}