问题描述

使用PowerShell脚本执行获取Azure订阅列表的指令（Get-Azsubscription -TenantId $tenantID -DefaultProfile $cxt）。在本地调试后，指令成功运行。

但是当指令并运行在Azure Function时，则出现了异常：详细的异常信息为

完成的错误信息为： \”Error getting value from \’Tags\’ on \’Microsoft.Azure.Commands.Profile.Models.PSAzureSubscription\’.\”

Microsoft.Azure.WebJobs.Script.Workers.Rpc.RpcException : Result: ERROR: Error getting value from \'Tags\' on \'Microsoft.Azure.Commands.Profile.Models.PSAzureSubscription\'.Exception             :Type           : Newtonsoft.Json.JsonSerializationExceptionTargetSite     :Name          : GetValueDeclaringType : Newtonsoft.Json.Serialization.ExpressionValueProviderMemberType    : MethodModule        : Newtonsoft.Json.dllStackTrace     :at Newtonsoft.Json.Serialization.ExpressionValueProvider.GetValue(Object target)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues(JsonWriter writer, Object value, JsonContainerContract contract, JsonProperty member, JsonProperty property, JsonContract& memberContract, Object& memberValue)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeDictionary(JsonWriter writer, IDictionary values, JsonDictionaryContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)at Newtonsoft.Json.JsonSerializer.Serialize(JsonWriter jsonWriter, Object value, Type objectType)at Newtonsoft.Json.JsonConvert.SerializeObjectInternal(Object value, Type type, JsonSerializer jsonSerializer)at Newtonsoft.Json.JsonConvert.SerializeObject(Object value, Type type, Formatting formatting, JsonSerializerSettings settings)at Newtonsoft.Json.JsonConvert.SerializeObject(Object value, Formatting formatting, JsonConverter[] converters)at Microsoft.Azure.Commands.Common.Authentication.Models.AzureRmProfile.ToString(Boolean serializeCache)at Microsoft.Azure.Commands.Common.Authentication.Models.AzureRmProfile.ToString()at System.Management.Automation.ParameterBinderBase.CoerceTypeAsNeeded(CommandParameterInternal argument, String parameterName, Type toType, ParameterCollectionTypeInformation collectionTypeInfo, Object currentValue)at System.Management.Automation.ParameterBinderBase.BindParameter(CommandParameterInternal parameter, CompiledCommandParameter parameterMetadata, ParameterBindingFlags flags)at System.Management.Automation.CmdletParameterBinderController.BindParameter(CommandParameterInternal argument, MergedCompiledCommandParameter parameter, ParameterBindingFlags flags)at System.Management.Automation.CmdletParameterBinderController.BindParameter(UInt32 parameterSets, CommandParameterInternal argument, MergedCompiledCommandParameter parameter, ParameterBindingFlags flags)at System.Management.Automation.CmdletParameterBinderController.BindParameters(UInt32 parameterSets, Collection`1 arguments)at System.Management.Automation.CmdletParameterBinderController.BindCommandLineParametersNoValidation(Collection`1 arguments)at System.Management.Automation.CmdletParameterBinderController.BindCommandLineParameters(Collection`1 arguments)at System.Management.Automation.CommandProcessor.BindCommandLineParameters()at System.Management.Automation.CommandProcessor.Prepare(IDictionary psDefaultParameterValues)at System.Management.Automation.CommandProcessorBase.DoPrepare(IDictionary psDefaultParameterValues)at System.Management.Automation.Internal.PipelineProcessor.Start(Boolean incomingStream)at System.Management.Automation.Internal.PipelineProcessor.SynchronousExecuteEnumerate(Object input)at System.Management.Automation.PipelineOps.InvokePipeline(Object input, Boolean ignoreInput, CommandParameterInternal[][] pipeElements, CommandBaseAst[] pipeElementAsts, CommandRedirection[][] commandRedirections, FunctionContext funcContext)at System.Management.Automation.Interpreter.ActionCallInstruction`6.Run(InterpretedFrame frame)at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)Message        : Error getting value from \'Tags\' on \'Microsoft.Azure.Commands.Profile.Models.PSAzureSubscription\'.Data           : System.Collections.ListDictionaryInternalInnerException :Type       : System.ArgumentNullExceptionMessage    : Value cannot be null. (Parameter \'value\')ParamName  : valueTargetSite :Name          : ArgumentNotNullDeclaringType : Newtonsoft.Json.Utilities.ValidationUtils, Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeedMemberType    : MethodModule        : Newtonsoft.Json.dllStackTrace :at Newtonsoft.Json.Utilities.ValidationUtils.ArgumentNotNull(Object value, String parameterName)at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value)at Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureSubscriptionExtensions.GetTags(IAzureSubscription subscription)at lambda_method(Closure , Object )at Newtonsoft.Json.Serialization.ExpressionValueProvider.GetValue(Object target)Source     : Newtonsoft.JsonHResult    : -2147467261Source         : Newtonsoft.JsonHResult        : -2146233088CategoryInfo          : OperationStopped: (:) [], JsonSerializationExceptionFullyQualifiedErrorId : Newtonsoft.Json.JsonSerializationExceptionInvocationInfo        :ScriptLineNumber : 26OffsetInLine     : 1HistoryId        : -1ScriptName       : D:\\home\\site\\wwwroot\\HttpTrigger1\\run.ps1Line             : $subs = Get-Azsubscription -TenantId $tenantID -DefaultProfile $cxtPositionMessage  : At D:\\home\\site\\wwwroot\\HttpTrigger1\\run.ps1:26 char:1+ $subs = Get-Azsubscription -TenantId $tenantID -DefaultProfile $cxt+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~PSScriptRoot     : D:\\home\\site\\wwwroot\\HttpTrigger1PSCommandPath    : D:\\home\\site\\wwwroot\\HttpTrigger1\\run.ps1CommandOrigin    : InternalScriptStackTrace      : at <ScriptBlock>, D:\\home\\site\\wwwroot\\HttpTrigger1\\run.ps1: line 26

问题分析及临时解决方案

对比以上本地可以成功运行，而在Azure Function中确出现JSON格式解析错误，所以排查PowerShell脚本错误问题。 那么就定位在运行脚本的环境问题。

第一步：排查PowerShell版本，及az 模块的版本

通过$PSVersionTable 打出PowerShell版本，通过Get-InstalledModule -name az 和Get-InstalledModule -name az.* 打印出当前环境的版本号。

经过对比，发现本地VM与Azure Function中Powershell和az 模块的版本都不同.

第二步：寻找临时的解决方案

由于Azure Function中PowerShell的版本从平台级别无法更改（可以修改PS脚本中所使用的az模块版本，修改方式见附件一）。所以主要的寻找发向为：基于现在的版本，从Get-Azsubscription指令本身来寻找Workaround呢？查看Get-Azsubscription指令，发现它使用的是当前登录用户的权限去获取所有的订阅号，指定TenantID是表明只获取当前TenantID下的所有订阅号。而参数DefaultProfile也是只携带用户认证信息，与当前登录的用户所有的认证信息重复。

如果不添加-DefaultProfile参数，是否同样由异常呢？ 经过验证执行成功并返回结果正确。所以作为Workaround的代码为：

# Write to the Azure Functions log stream.Write-Host \"PowerShell HTTP trigger function processed a request.\"$User = \"XXXXXXXXXXXXXxxxxxxxx\"$PWord = ConvertTo-SecureString -String \"XXXXXXXXXXXXXxxxxxxxx\" -AsPlainText -Force$Credential = New-Object System.Management.Automation.PSCredential($User, $PWord)Connect-AzAccount -Environment AzureChinaCloud -Credential $CredentialWrite-Host \"login successfully\"$tenantID = \"xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\"$cxt = Set-AzContext -Tenant $tenantIDwrite-host $cxtwrite-host \"no defaultprofile\"Write-Host \"Get-Azsubscription -TenantId $tenantID\"#$subs = Get-Azsubscription -TenantId $tenantID -DefaultProfile $cxtGet-Azsubscription -TenantId $tenantIDwrite-host \"=========================\"write-host $subs

附件一：在Azure Funciton中修改az的版本号为5.2.0, 问题也得到解决。

在Azure Function 门户页面，点击“App Service Editor (Preview)” 目录，进入Editor页面，在文件requirements.psd1文件中，修改az的版本号为5.2.0. 保存后，回到Azure Function页面。重启Function. 修改页面如下：

结论:解决办法有两种

1. 修改az的版本号为5.2.0，修改办法见附件一
2. 修改Get-Azsubscription指令，去掉参数-DefaultProfile $cxt

参考资料

Get-AzSubscription ：https://docs.microsoft.com/en-us/powershell/module/az.accounts/get-azsubscription?view=azps-6.2.0