将APIM从stv1迁移至stv2时Pipeline报错：not enough values to unpack

我正尝试使用Azure CLI脚本将API管理（APIM）从平台版本stv1迁移至stv2，所用脚本如下：

- task: AzureCLI@2
  displayName: "Migrating Platform Version of APIM to stv2"
  inputs:
    azureSubscription: ${{ parameters.Subscription }}
    scriptType: 'pscore' 
    scriptLocation: 'inlineScript' 
    inlineScript: |
        $APIMName = "$(api_management_service_name)"
        $ResourceGroup = "$(resource_group)"
        $APIM_PlatformVersion = az apim show --name $APIMName --resource-group $ResourceGroup --query platformVersion --output tsv
        if($APIM_PlatformVersion -contains 'stv1'){
          $headers = @{
            'Content-Type' = 'application/json' 
          }
           $APIM_ResourceId = az apim show --name $APIMName --resource-group $ResourceGroup --query id --output tsv
           Write-Host "Migrating to stv2 as the current version is $APIM_PlatformVersion"
           # Call REST API to migrate to stv2 and preserve VIP address
           az rest --method post --uri "$APIM_ResourceId/migrateToStv2?api-version=2023-03-01-preview" --body '{"mode": "PreserveIp"}' --headers $headers
        }
        else{
           Write-Host "APIM already in $APIM_PlatformVersion"
        }

执行时触发如下错误：

ERROR: The command failed with an unexpected error. Here is the traceback:
ERROR: not enough values to unpack (expected 2, got 1)

报错原因 #

这个错误是因为PowerShell哈希表无法直接传递给Azure CLI的--headers参数。Azure CLI要求--headers的参数格式是key=value的字符串键值对，直接传入PowerShell哈希表对象会导致CLI解析时无法正确拆解键值对，从而抛出"not enough values to unpack"异常。

解决方法 #

可以通过两种方式修复这个问题：

方式1：直接在az rest命令中指定headers字符串 #

不需要定义哈希表，直接用Content-Type=application/json的格式传递参数：

- task: AzureCLI@2
  displayName: "Migrating Platform Version of APIM to stv2"
  inputs:
    azureSubscription: ${{ parameters.Subscription }}
    scriptType: 'pscore' 
    scriptLocation: 'inlineScript' 
    inlineScript: |
        $APIMName = "$(api_management_service_name)"
        $ResourceGroup = "$(resource_group)"
        $APIM_PlatformVersion = az apim show --name $APIMName --resource-group $ResourceGroup --query platformVersion --output tsv
        if($APIM_PlatformVersion -contains 'stv1'){
           $APIM_ResourceId = az apim show --name $APIMName --resource-group $ResourceGroup --query id --output tsv
           Write-Host "Migrating to stv2 as the current version is $APIM_PlatformVersion"
           # Call REST API to migrate to stv2 and preserve VIP address
           az rest --method post --uri "$APIM_ResourceId/migrateToStv2?api-version=2023-03-01-preview" --body '{"mode": "PreserveIp"}' --headers Content-Type=application/json
        }
        else{
           Write-Host "APIM already in $APIM_PlatformVersion"
        }

方式2：将哈希表转换为CLI兼容的格式 #

如果需要保留哈希表（比如多headers场景），可以把哈希表转换成key=value的字符串数组：

- task: AzureCLI@2
  displayName: "Migrating Platform Version of APIM to stv2"
  inputs:
    azureSubscription: ${{ parameters.Subscription }}
    scriptType: 'pscore' 
    scriptLocation: 'inlineScript' 
    inlineScript: |
        $APIMName = "$(api_management_service_name)"
        $ResourceGroup = "$(resource_group)"
        $APIM_PlatformVersion = az apim show --name $APIMName --resource-group $ResourceGroup --query platformVersion --output tsv
        if($APIM_PlatformVersion -contains 'stv1'){
          $headers = @{
            'Content-Type' = 'application/json' 
          }
          # 转换为CLI兼容的键值对字符串数组
          $cliHeaders = $headers.GetEnumerator() | ForEach-Object { "$($_.Key)=$($_.Value)" }
          
           $APIM_ResourceId = az apim show --name $APIMName --resource-group $ResourceGroup --query id --output tsv
           Write-Host "Migrating to stv2 as the current version is $APIM_PlatformVersion"
           # Call REST API to migrate to stv2 and preserve VIP address
           az rest --method post --uri "$APIM_ResourceId/migrateToStv2?api-version=2023-03-01-preview" --body '{"mode": "PreserveIp"}' --headers $cliHeaders
        }
        else{
           Write-Host "APIM already in $APIM_PlatformVersion"
        }

额外建议：可以在脚本中增加Write-Host $APIM_PlatformVersion输出，确认该变量的取值是否正确，避免因为取值为空导致逻辑判断异常。

内容的提问来源于stack exchange，提问作者QuestingSoul