在Bicep中传入连接字符串数组配置App Service循环时报错

问题场景 #

通过CI/CD管道部署Azure应用服务时，尝试用Bicep循环配置连接字符串，参数文件中定义了connectionStrings数组，但部署时收到反序列化错误，提示无法将JSON数组转为DeploymentParameterDefinition类型。

参数文件代码：

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        // Required Parameters
        ...
        // Optional Parameters
        "connectionStrings": [
            {
                "name": "Tracking",
                "connectionString": "...",
                "type": "SQLServer"
            },
            {
                "name": "Logs",
                "connectionString": "...",
                "type": "SQLServer"
            }
        ],
        ...
    }
}

Bicep模块（appService.bicep）中的循环代码：

resource appServiceWeb 'Microsoft.Web/sites@2022-03-01' = {
  name: nameWeb
  location: location
  tags: tags
  kind: kind
  identity: {
    type: 'SystemAssigned'
  }
  properties: {
    serverFarmId: appServicePlan_id
    siteConfig: {
      appSettings: [
        ...
      ]
      connectionStrings: [for connectionString in connectionStrings: {
        name: connectionString.name
        connectionString: connectionString.connectionString
        type: connectionString.type
      }]
    }
  }
}

错误信息：

{
  "code": "InvalidRequestContent",
  "message": "The request content was invalid and could not be deserialized: 'Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'Azure.Deployments.Core.Definitions.DeploymentParameterDefinition' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly.\r\nTo fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List<T> that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array.\r\nPath 'properties.parameters.connectionStrings', line 1, position 280.'."
}

错误原因 #

Azure部署参数文件的规范要求：所有类型的参数都必须通过value字段传递值，包括数组类型。当前参数文件中connectionStrings直接以数组形式作为参数值，不符合规范，导致Azure无法正确解析参数类型。

修复方案 #

1. 修改参数文件格式 #

将connectionStrings数组包裹在value对象中，修正后的参数文件如下：

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        // Required Parameters
        ...
        // Optional Parameters
        "connectionStrings": {
            "value": [
                {
                    "name": "Tracking",
                    "connectionString": "...",
                    "type": "SQLServer"
                },
                {
                    "name": "Logs",
                    "connectionString": "...",
                    "type": "SQLServer"
                }
            ]
        },
        ...
    }
}

2. 保留Bicep代码逻辑 #

main.bicep和appService.bicep中的参数定义（param connectionStrings array）以及循环配置连接字符串的代码无需修改，保持原样即可。

验证 #

修改参数文件后重新触发CI/CD部署，即可正常解析数组参数，连接字符串会被正确批量配置到Azure应用服务中。

内容的提问来源于stack exchange，提问作者Ross