{
   "if": {
      "allOf": [
         {
            "field": "type",
            "in": [
               "Microsoft.Compute/disks",
               "Microsoft.Compute/virtualMachines",
               "Microsoft.Compute/VirtualMachineScaleSets"
            ]
         },
         {
            "not": {
               "allOf": [
                  {
                     "field": "Microsoft.Compute/imagePublisher",
                     "in": [
                        "Canonical"
                     ]
                  },
                  {
                     "field": "Microsoft.Compute/imageOffer",
                     "in": [
                        "UbuntuServer"
                     ]
                  },
                  {
                     "field": "Microsoft.Compute/imageSku",
                     "in": [
                        "14.04.2-LTS"
                     ]
                  }
               ]
            }
         }
      ]
   },
   "then": {
      "effect": "deny"
   }
}