从ARM模板的customData (cloud-init)部分访问密钥库中的密钥

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "keyVaultName": {
      "type": "string",
      "metadata": {
        "description": "The name of the key vault"
      }
    },
    "keyName": {
      "type": "string",
      "metadata": {
        "description": "The name of the key in the key vault"
      }
    }
  },
  "resources": [
    {
      "type": "Microsoft.Compute/virtualMachines",
      "apiVersion": "2021-03-01",
      "name": "[variables('vmName')]",
      "properties": {
        "hardwareProfile": {
          "vmSize": "[variables('vmSize')]"
        },
        "storageProfile": {
          "imageReference": {
            "publisher": "Canonical",
            "offer": "UbuntuServer",
            "sku": "18.04-LTS",
            "version": "latest"
          },
          "osDisk": {
            "createOption": "FromImage"
          }
        },
        "osProfile": {
          "computerName": "[variables('vmName')]",
          "adminUsername": "[parameters('adminUsername')]",
          "adminPassword": "[parameters('adminPassword')]",
          "customData": "[base64(concat('#cloud-config\n', 'runcmd:\n', '- echo \"', parameters('keyVaultId'), '/secrets/', parameters('keyName'), '=$(az keyvault secret show --vault-name ', parameters('keyVaultName'), ' --name ', parameters('keyName'), ' --query value -o tsv)\", >> /etc/environment\n'))]"
        },
        "networkProfile": {
          "networkInterfaces": [
            {
              "id": "[resourceId('Microsoft.Network/networkInterfaces', variables('nicName'))]"
            }
          ]
        }
      }
    },
    {
      "type": "Microsoft.KeyVault/vaults",
      "apiVersion": "2019-09-01",
      "name": "[parameters('keyVaultName')]",
      "properties": {
        "tenantId": "[subscription().tenantId]",
        "sku": {
          "family": "A",
          "name": "standard"
        },
        "enabledForDeployment": true
      }
    }
  ]
}