Pass through the HTTP response to the client in MVC 6 - asp.net-mvc

Question

I am new to Web API and HTTP.
I am using the MVC 6 (beta version). I have a proxy service (Web API) which has a POST method to get response from another service with XML content returned. I need to return the response content to the client since the client can't call the service directly.
// In my proxy service
public HttpResponseMessage Post(String content)
{
using ( HttpClient client = new HttpClient() ) {
.......
HttpResponseMessage response = client.PostAsync(uri, content).Result;
// I get everything I need in the "response".
// How to return the response or it body to the client.
// return response;
}
}
II need to return the "response" to the client with no or minimum changes. I tried "return response", or create a new HttpResponseMessage, but I only got something like
{"Headers":[{"Key":"Content-Type","Value":["text/xml"]}]}
in the body.
So is there a simple way to pass the response back to the client? Thanks.

Answer 1

The ASP.NET team is currently working on a "proxy middleware" that does exactly what you're looking for: https://github.com/aspnet/Proxy
Here's how it works internally:
public async Task Invoke(HttpContext context)
{
var requestMessage = new HttpRequestMessage();
if (string.Equals(context.Request.Method, "POST", StringComparison.OrdinalIgnoreCase))
{
var streamContent = new StreamContent(context.Request.Body);
requestMessage.Content = streamContent;
}
// Copy the request headers
foreach (var header in context.Request.Headers)
{
if (!requestMessage.Headers.TryAddWithoutValidation(header.Key, header.Value) && requestMessage.Content != null)
{
requestMessage.Content?.Headers.TryAddWithoutValidation(header.Key, header.Value);
}
}
requestMessage.Headers.Host = _options.Host + ":" + _options.Port;
var uriString = $"{_options.Scheme}://{_options.Host}:{_options.Port}{context.Request.PathBase}{context.Request.Path}{context.Request.QueryString}";
requestMessage.RequestUri = new Uri(uriString);
requestMessage.Method = new HttpMethod(context.Request.Method);
using (var responseMessage = await _httpClient.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead, context.RequestAborted))
{
context.Response.StatusCode = (int)responseMessage.StatusCode;
foreach (var header in responseMessage.Headers)
{
context.Response.Headers.SetValues(header.Key, header.Value.ToArray());
}
foreach (var header in responseMessage.Content.Headers)
{
context.Response.Headers.SetValues(header.Key, header.Value.ToArray());
}
// SendAsync removes chunking from the response. This removes the header so it doesn't expect a chunked response.
context.Response.Headers.Remove("transfer-encoding");
await responseMessage.Content.CopyToAsync(context.Response.Body);
}
}
https://github.com/aspnet/Proxy/blob/dev/src/Microsoft.AspNet.Proxy/ProxyMiddleware.cs