vb.net - 使用 FtpWebRequest 将文件从 azure 托管应用程序上传到外部 ftp 站点

Question

UPDATE: I found out that it is not an issue with azure rather the other party who are actually doing white-listing on incoming connection.

我实现了一个服务，它打开 ftp 连接来将文件上传到远程 FTP 服务器。 代码在我的桌面上运行完美(!)，但是如果我将其发布到 azure 托管云并使用完全相同的参数执行，我会收到 WebException 并显示消息“远程服务器返回错误:(530)不”已登录。' 我在 azure 控制台中没有找到任何相关设置。我还尝试了不同的设置，例如开/关保持事件和被动，但结果是相同的。你们知道可能是什么问题吗？

引用代码:

            Dim request As FtpWebRequest

            request = TryCast(WebRequest.Create($"ftp://{_host}/inventory/{_uploadFilename}"), FtpWebRequest)
            request.Method = WebRequestMethods.Ftp.UploadFile
            request.Credentials = New NetworkCredential(_username, _password)
            request.UsePassive = True
            request.UseBinary = True
            request.KeepAlive = False

            Using fs As FileStream = File.OpenRead(_fileName)
                Dim buffer As Byte() = New Byte(fs.Length - 1) {}
                fs.Read(buffer, 0, buffer.Length)
                fs.Close()
                Dim requestStream As Stream = request.GetRequestStream()
                requestStream.Write(buffer, 0, buffer.Length)
                requestStream.Flush()
                requestStream.Close()


                Dim response As FtpWebResponse = DirectCast(request.GetResponse(), FtpWebResponse)
                Return Ok($"Remote server response: {response.StatusDescription}")

            End Using

Answer 1

NetworkCredential 从哪里获取凭据？

Windows 身份验证 (Kerberos/NTLM) 在 Azure 中不起作用。您需要使用 FTP 登录(如 USER 和 PASS FTP 命令)。

尝试从 Azure 进行 FTP 传输时，始终使用被动模式。

Imports System.IO
Imports System.Net

Module Module1

    Sub Main()
        Dim request As FtpWebRequest
        Dim _host = "remote.ftpserver.com"
        Dim _uploadFilename = "file.txt"
        Dim _filename = "file.txt"
        Dim _username = "Username"
        Dim _password = "PaSsw0rD"

        request = TryCast(WebRequest.Create($"ftp://{_host}/path/{_uploadFilename}"),
            FtpWebRequest)
        request.Method = WebRequestMethods.Ftp.UploadFile
        request.Credentials = New NetworkCredential(_username, _password)
        request.UsePassive = True
        request.UseBinary = True
        request.KeepAlive = False

        Using fs As FileStream = File.OpenRead(_filename)
            Dim buffer As Byte() = New Byte(fs.Length - 1) {}
            fs.Read(buffer, 0, buffer.Length)
            fs.Close()
            Dim requestStream As Stream = request.GetRequestStream()
            requestStream.Write(buffer, 0, buffer.Length)
            requestStream.Flush()
            requestStream.Close()
            Dim response As FtpWebResponse = DirectCast(request.GetResponse(),
                FtpWebResponse)
            Console.WriteLine($"Remote server response: {response.StatusCode}, 
                {response.StatusDescription}")
        End Using
    End Sub

End Module

如果格式有问题，我们深表歉意。这是我第一次尝试编写VB。

在Kudu's DebugConsole中运行它为了清楚起见 - 与 Web 应用程序相同的沙箱:

在远程 FTP 服务器上:

ftp> ls file.txt
200 PORT command successful.
125 Data connection already open; Transfer starting.
file.txt
226 Transfer complete.
ftp: 13 bytes received in 0.02Seconds 0.81Kbytes/sec.

ftp> bin
200 Type set to I.

ftp> get file.txt
200 PORT command successful.
125 Data connection already open; Transfer starting.
226 Transfer complete.
ftp: 24 bytes received in 0.18Seconds 0.14Kbytes/sec.

ftp> !type file.txt
Upped with FtpWebRequest