使用powershell脚本获取函数键时出错

我有一个http触发的azure函数,我需要在部署期间填充其函数键。我目前正在尝试使用给定的过程获取功能键 here (我只调用函数键API,而不是调用主机键API /admin/functions/$functionName/keys?code=$masterKey ). 当我使用KUDU zip API将压缩后的函数代码上传到函数应用程序时,我正在调用API。

我面临的问题是,在尝试设置功能应用程序的应用程序设置时,我遇到了错误

调用RestMethod:{“id”:“643ea0b3-5ffe-4683-a8d3-62daec8c8db9”,“requestId”:“ec5461d6-57bc-45dd-b3ac-358602cfa94c”,“statusCode”:500,“errorCode”:0,“message”: 值不能为null。\r\n参数名称:源“}

但当我在当地尝试时,这是可行的。我怀疑在我进行REST调用以获取函数键时,函数是否尚未部署,从而导致错误。错误消息的含义是什么?我如何修复它?。这是暂时的问题吗?

更新:代码段

function get_credentials($resourceGroupName, $functionAppName){
$creds = Invoke-AzureRmResourceAction -ResourceGroupName $resourceGroupName `
-ResourceType Microsoft.Web/sites/config -ResourceName "$functionAppName/publishingcredentials" `
-Action list -ApiVersion 2015-08-01 -Force

$username = $creds.Properties.PublishingUserName
$password = $creds.Properties.PublishingPassword
$base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $username, $password)))
return $base64AuthInfo
}
function get_master_key($kuduAuthToken, $functionAppName ){
    Write-Host "KUDU token is $kuduAuthToken"
    $apiUrl = "https://$functionAppName.scm.azurewebsites.net/api/functions/admin/masterkey"
    $result = Invoke-RestMethod -Uri $apiUrl -Headers @{"Authorization"="Basic $kuduAuthToken";"If-Match"="*"} 
    $masterKey = $result.masterKey
    Write-Host "master key is $masterKey"
    return $masterKey
}

function get_function_key($functionAppName, $functionName, $masterKey ){

    $apiUrl = "https://$functionAppName.azurewebsites.net/admin/functions/$functionName/keys?code=$masterKey"
    Write-Host "Calling $apiUrl"
    $result = Invoke-RestMethod -Uri $apiUrl 
    Write-Host "Result is $result"
    return $result.keys[0].value
    Write-Host "host token is $result"
}
$authToken = get_credentials $resourceGroupName $functionAppName
$masterKey = get_master_key $authToken $functionAppName
get_function_key $functionAppName $purgeFunctionName $masterKey