SftpService.cs

public class SftpService
{
    private readonly ILogger<SftpService> _logger;
    private readonly SftpConfig _config;

    public SftpService(ILogger<SftpService> logger, SftpConfig sftpConfig)
    {
        _logger = logger;
        _config = sftpConfig;
    }

    public IEnumerable<SftpFile> ListAllFiles(string remoteDirectory = ".")
    {
        using var client = new SftpClient(_config.Host, _config.Port == 0 ? 22 : _config.Port, _config.UserName, _config.Password);
        try
        {
            client.Connect();
            return client.ListDirectory(remoteDirectory);
        }
        catch (Exception exception)
        {
            _logger.LogError(exception, $"Failed in listing files under [{remoteDirectory}]");
            return null;
        }
        finally
        {
            client.Disconnect();
        }
    }

    public void UploadFile(string localFilePath, string remoteFilePath)
    {
        using var client = new SftpClient(_config.Host, _config.Port == 0 ? 22 : _config.Port, _config.UserName, _config.Password);
        try
        {
            client.Connect();
            using var s = File.OpenRead(localFilePath);
            client.UploadFile(s, remoteFilePath);
            _logger.LogInformation($"Finished uploading file [{localFilePath}] to [{remoteFilePath}]");
        }
        catch (Exception exception)
        {
            _logger.LogError(exception, $"Failed in uploading file [{localFilePath}] to [{remoteFilePath}]");
        }
        finally
        {
            client.Disconnect();
        }
    }

    public void DownloadFile(string remoteFilePath, string localFilePath)
    {
        using var client = new SftpClient(_config.Host, _config.Port == 0 ? 22 : _config.Port, _config.UserName, _config.Password);
        try
        {
            client.Connect();
            using var s = File.Create(localFilePath);
            client.DownloadFile(remoteFilePath, s);
            _logger.LogInformation($"Finished downloading file [{localFilePath}] from [{remoteFilePath}]");
        }
        catch (Exception exception)
        {
            _logger.LogError(exception, $"Failed in downloading file [{localFilePath}] from [{remoteFilePath}]");
        }
        finally
        {
            client.Disconnect();
        }
    }

    public void DeleteFile(string remoteFilePath)
    {
        using var client = new SftpClient(_config.Host, _config.Port == 0 ? 22 : _config.Port, _config.UserName, _config.Password);
        try
        {
            client.Connect();
            client.DeleteFile(remoteFilePath);
            _logger.LogInformation($"File [{remoteFilePath}] deleted.");
        }
        catch (Exception exception)
        {
            _logger.LogError(exception, $"Failed in deleting file [{remoteFilePath}]");
        }
        finally
        {
            client.Disconnect();
        }
    }
}