{
  "$schema": "https://schema.management.azure.com/schemas/2019-08-01/managementGroupDeploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "metadata": {
    "_generator": {
      "name": "bicep",
      "version": "0.22.6.54827",
      "templateHash": "9602921085150405773"
    }
  },
  "resources": [
    {
      "type": "Microsoft.Authorization/policyDefinitions",
      "apiVersion": "2021-06-01",
      "name": "policyDef",
      "properties": {
        "displayName": "Automatically deploy an application on virtual machines",
        "description": "This policy will automatically deploy an application in the shared compute gallery.",
        "mode": "All",
        "parameters": {
          "applicationVersion": {
            "type": "String"
          },
          "applicationName": {
            "type": "String"
          }
        },
        "policyRule": {
          "if": {
            "allOf": [
              {
                "field": "type",
                "equals": "Microsoft.Compute/virtualMachines"
              },
              {
                "field": "Microsoft.Compute/virtualMachines/storageProfile.osDisk.osType",
                "equals": "Windows"
              }
            ]
          },
          "then": {
            "effect": "deployIfNotExists",
            "details": {
              "type": "Microsoft.Compute/virtualMachines",
              "name": "[[field('name')]",
              "existenceCondition": {
                "allOf": [
                  {
                    "count": {
                      "field": "Microsoft.Compute/virtualMachines/applicationProfile.galleryApplications[*]",
                      "where": {
                        "field": "Microsoft.Compute/virtualMachines/applicationProfile.galleryApplications[*].packageReferenceId",
                        "equals": "[[parameters('applicationVersion')]"
                      }
                    },
                    "greater": 0
                  }
                ]
              },
              "roleDefinitionIds": [
                "/providers/Microsoft.Authorization/roleDefinitions/8e3af657-a8ff-443c-a75c-2fe8c4bcb635"
              ],
              "deployment": {
                "properties": {
                  "mode": "incremental",
                  "template": {
                    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json",
                    "contentVersion": "1.0.0.0",
                    "parameters": {
                      "vmName": {
                        "type": "string"
                      },
                      "location": {
                        "type": "string"
                      },
                      "packageReferenceId": {
                        "type": "string"
                      },
                      "applicationName": {
                        "type": "string"
                      }
                    },
                    "resources": [
                      {
                        "apiVersion": "2021-07-01",
                        "type": "Microsoft.Compute/virtualMachines/VMapplications",
                        "name": "[[concat(parameters('vmName'), '/', parameters('applicationName'))]",
                        "location": "[[parameters('location')]",
                        "properties": {
                          "packageReferenceId": "[[parameters('packageReferenceId')]"
                        }
                      }
                    ]
                  },
                  "parameters": {
                    "vmName": {
                      "value": "[[field('name')]"
                    },
                    "location": {
                      "value": "[[field('location')]"
                    },
                    "packageReferenceId": {
                      "value": "[[parameters('applicationVersion')]"
                    },
                    "applicationName": {
                      "value": "[[parameters('applicationName')]"
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  ]
}