如何从PowerShell请求的404页面获得响应

Question

我必须调用TeamCity公开的API,告诉我用户是否存在.API网址是这样的:http://myteamcityserver.com:8080/httpAuth/app/rest/users/monkey

从浏览器(或fiddler)调用时,我得到以下内容:

Error has occurred during request processing (Not Found).
Error: jetbrains.buildServer.server.rest.errors.NotFoundException: No user can be found by username 'monkey'.
Could not find the entity requested. Check the reference is correct and the user has permissions to access the entity.

我必须使用powershell调用API.当我这样做时,我得到一个例外,我没有看到上面的文字.这是我使用的powershell:

try{
    $client = New-Object System.Net.WebClient
    $client.Credentials = New-Object System.Net.NetworkCredential $TeamCityAgentUserName, $TeamCityAgentPassword
    $teamCityUser = $client.DownloadString($url)
    return $teamCityUser
}
catch
{
    $exceptionDetails = $_.Exception
    Write-Host "$exceptionDetails" -foregroundcolor "red"
}

例外:

System.Management.Automation.MethodInvocationException: Exception calling "DownloadString" with "1" argument(s): "The remote server returned an error: (404) Not Found." ---> System.Net.WebException: The remote server returned an error: (404) Not Found.
   at System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)
   at System.Net.WebClient.DownloadString(Uri address)
   at CallSite.Target(Closure , CallSite , Object , Object )
   --- End of inner exception stack trace ---
   at System.Management.Automation.ExceptionHandlingOps.CheckActionPreference(FunctionContext funcContext, Exception exception)
   at System.Management.Automation.Interpreter.ActionCallInstruction`2.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)

我需要能够检查返回的页面是否包含上述文本.这样我知道是否应该自动创建新用户.我可以检查404,但我担心的是,如果API被更改并且呼叫确实返回404,那么我就不会更聪明了.

Answer 1

更改catch子句以捕获更具体的WebException,然后您可以使用Response它上面的属性来获取状态代码:

{
  #...
} 
catch [System.Net.WebException] 
{
    $statusCode = [int]$_.Exception.Response.StatusCode
    $html = $_.Exception.Response.StatusDescription
}

Answer 2

您可以尝试使用 Internet Explorer COM 对象。它允许您检查浏览器返回代码并导航 HTML 对象模型。

注意：我发现您需要从提升的 PowerShell 提示符运行此命令才能维护 COM 对象定义。

$url = "http://myteamcityserver.com:8080/httpAuth/app/rest/users/monkey"
$ie = New-Object -ComObject InternetExplorer.Application

添加此以查看浏览器

$ie.visibility = $true

导航至该网站

$ie.navigate($url)

这将暂停脚本，直到页面完全加载

do { start-sleep -Milliseconds 250 } until ($ie.ReadyState -eq 4)

然后验证您的 URL 以确保它不是错误页面

if ($ie.document.url -ne $url) { 
   Write-Host "Site Failed to Load" -ForegroundColor "RED"
} else {
   [Retrieve and Return Data]
}

您可以通过 $ie.document 导航 HTML 对象模型。使用 Get-Member 和 HTML 方法，例如 GetElementsByTagName() 或 GetElementById()。

如果凭据是一个问题，请将其构建到函数中，然后使用 Invoke-Command 和 -Credentials 参数来定义您的登录信息。