I am trying to get a File that is being sent (from Postman) in the body of a POST request to my REST API that is self hosted using Owin. While debugging I can confirm that the correct endpoint it being reached but HttpContext.Current returns null always. Pretty much HttpContext.anything returns null. So I don't understand how I am supposed to receive a File via POST request and process it in my REST API while using Owin self hosting. I have tried Request.GetOwinContext() but that doesn't return anything useful.
How do I achieve this?
The Request property of a controller can help access the file.
public class FileController : ApiController
{
[HttpPost]
public async Task Post()
{
if (Request.Content.IsMimeMultipartContent())
{
var multipartContent = await Request.Content.ReadAsMultipartAsync();
// "thefile" is the form field name
HttpContent httpContent = multipartContent.Contents
.Where(c => c.Headers.ContentDisposition.Name == "\"thefile\"")
.Single();
// httpContent contains the file, for example:
var fileContents = await httpContent.ReadAsStringAsync();
}
}
}
Related
This question already has answers here:
Parsing Json rest api response in C# [duplicate]
(3 answers)
Closed 12 months ago.
tl;dr: I have an API that works in the browser, but I can't figure out how to return a list of items so I can traverse them in a List.
Long version:
I'm still struggling with API's and now I've hit another snag. I have the following code in my API:
[Route("api/[controller]")]
[ApiController]
public class ScheduleController : Controller
{
[HttpGet]
public IEnumerable<Schedule> GetAllSchedules()
{
using (ScheduleDataEntities entities = new ScheduleDataEntities())
{
return entities.Schedule.ToList();
}
}
[HttpGet("{id}")]
public Schedule GetIndividualSchedule(int id)
{
using (ScheduleDataEntities entities = new ScheduleDataEntities())
return entities.Schedule.FirstOrDefault(e => e.ScheduleID == id);
}
}
When I navigate to my localhost (https://localhost:7017/api/schedule) it returns the data just fine:
[{"userID":121,"weekDay":"Monday","startTime":"07:00:00","endTime":"07:15:00","createdDate":"2022-01-18T22:11:34.8966667","modifiedDate":"2022-01-18T22:11:34.8966667","active":false,"scheduleID":14414,"dayOfWeek":1,"tsType":"Normal"},
{"userID":94,"weekDay":"Wednesday","startTime":"08:45:00","endTime":"09:00:00","createdDate":"2021-11-03T13:50:50.26","modifiedDate":"2021-11-03T13:50:50.26","active":false,"scheduleID":13160,"dayOfWeek":3,"tsType":"Normal"}
...]
So far, so good. Now, I want to return the list to the client calling the API. I've made a simple test client that should get the list when I press a button:
client.Dispose();
client = new HttpClient();
client.BaseAddress = new Uri("https://localhost:7017/api/schedule/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
List<Schedule> list = GetScheduleList("https://localhost:7017/api/schedule");
//Do something with the list...
However, I can't figure out how this method should work:
static List<Schedule> GetScheduleList(string path)
{
List<Schedule> schedules = null;
HttpResponseMessage response = client.GetAsync(path);
return schedules;
}
Every tutorial I can find online, says to use GetAsync. However, that only works with the await keyword. Adding the await keyword means I have to add the async keyword to my method, which means I must return a Task<List> or a task-like type, which can't be converted to a List. If I return it as a Task, how can I then break it back down into my list of schedules?
I really feel like I've tried anything I've come across, so any help you can give is much appreciated.
try this
static async Task<List<Schedule>> GetScheduleList(string path)
{
var response = await client.GetAsync(path);
if (response.IsSuccessStatusCode)
{
var stringData = await response.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<List<Schedule>>(stringData);
}
return null;
and fix the method call
List<Schedule> list = await GetScheduleList("https://localhost:7017/api/schedule");
or you can try, if you don't use async
List<Schedule> list = GetScheduleList("https://localhost:7017/api/schedule").Result;
did you try to start the web app in debug mode and find the return of the API ?
You can even use console.log to give more details;
Otherwise, I was there one day. it's CORS problem. you should add the header : Access-Control-Allow-Origin should have wildcard "*" as a value in order to be able to call https APIs on http servers.
I am connecting to a 3rd party API that requires calls to retrieve an authorization code and a token.
The API requires a redirect URL, which when returned, contains the authorization code attached to the query string.
So, on my side so I set up this controller below that will read the queryString.
Then, my app needs to fire a POST request to the API to get the token, and you will see me calling the controller the contains the POST request.
When I click my button to connect to the API, in my browser window, I do see that I am redirected to the GetGeologicalPeriod() controller below because I see the message:
you have reached the GeologicalPeriod endpoint.
And I do see the authorization code in the query string.
But I don't see anything else, no errors, nothing.
I was expecting to see the results retuned from the call to GetGeologicalPeriodToken, or at least an error that it failed, but I am getting nothing...not even in the browser console window.
So I am kind of at a loss as to what is actually happening.
Since this is on a development server, I can't step through it locally in Visual Studio.
Is there anyway to show messages or write to console so I can see what's going on?
Thanks!
[ApiController]
public class GeologicalPeriodController : ControllerBase
{
[HttpGet]
public ActionResult<String> GetGeologicalPeriod()
{
string getTest = "you have reached the GeologicalPeriod endpoint.";
var queryString = Request.Query["code"];
var postResult = GetGeologicalPeriodToken(queryString);
return postResult;
}
[HttpPost("AuthRequest")]
public ActionResult<String> GetGeologicalPeriodToken(string authCode)
{
string authToken = authCode;
string authString = "admin";
var queryString = Request.Query["code"];
var client = new RestClient("https://geologicalPeriod.geo.gov/oauth/token?accessType=professor&code=" + authCode + "&redirect_uri=https://jamaica.round.astro.edu/api/geologicalPeriodauth/geologicalPeriod/AuthRequest");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", authString);
IRestResponse response = client.Execute(request);
var apiResponse = response;
return apiResponse.Content.ToString();
}
I'm working on a project where we have to develop a web API with ASP .NET Core 3.x. So far, so good, it is running well. Now, I'm writing some integration tests for this web API and I have some trouble to get the tests for everything else than GET request to work.
We're using the Clean Architecture from Jason Taylor. This means we have a core project with all our request handler, a domain project with all database entities and a presentation project for the API controllers. We use MediatR and dependency injection for the communication between these projects.
Now, we have the problem that the body data of the reuqest doesn't reach the controller.
This is how the Update method in the controller looks like:
[ApiController]
[Route("api/[controller]/[action]")]
public abstract class BaseController : ControllerBase
{
private IMediator _mediator;
protected IMediator Mediator => _mediator ??= HttpContext.RequestServices.GetService<IMediator>();
}
public class FavoriteController : BaseController
{
[HttpPut("{id}")]
[ProducesResponseType(StatusCodes.Status204NoContent)]
[ProducesResponseType(StatusCodes.Status404NotFound)]
public async Task<IActionResult> Update(long id, UpdateFavoriteCommand command)
{
if (command == null || id != command.Id)
{
return BadRequest();
}
// Sends the request to the corresponding IRequestHandler
await Mediator.Send(command);
return NoContent();
}
}
We use xUnit.net as test framework.
For the integration tests, we're using an InMemory SQLite database which is setup in a fixture class.
The test looks like the following:
public class UpdateFavoritesTestSqlite : IClassFixture<WebApplicationFactoryWithInMemorySqlite<Startup>>
{
private readonly WebApplicationFactoryWithInMemorySqlite<Startup> _factory;
private readonly string _endpoint;
public UpdateFavoritesTestSqlite(WebApplicationFactoryWithInMemorySqlite<Startup> factory)
{
_factory = factory;
_endpoint = "api/Favorite/Update/";
}
[Fact]
public async Task UpdateFavoriteDetail_WithFullUpdate_ShouldUpdateCorrectly()
{
// Arange
var client = _factory.CreateClient(); // WebApplicationFactory.CreateClient()
var command = new UpdateFavoriteCommand
{
Id = 5,
Caption = "caption new",
FavoriteName = "a new name",
Public = true
};
// Convert to JSON
var jsonString = JsonConvert.SerializeObject(command);
var httpContent = new StringContent(jsonString, Encoding.UTF8, "application/json");
var stringUri = client.BaseAddress + _endpoint + command.Id;
var uri = new Uri(stringUri);
// Act
var response = await client.PutAsync(uri, httpContent);
response.EnsureSuccessStatusCode();
httpContent.Dispose();
// Assert
response.StatusCode.ShouldBe(HttpStatusCode.NoContent);
}
}
If we run the test, we get an 400 Bad Request error.
If we run the test in Debug mode, we can see that the code throws a custom ValidationException because of a model state error. This is configured in the DependencyInjection of the presentation project:
services
.AddControllers()
.ConfigureApiBehaviorOptions(options =>
{
options.InvalidModelStateResponseFactory = context =>
{
var failures = context.ModelState.Keys
.Where(k => ModelValidationState.Invalid.Equals(context.ModelState[k].ValidationState))
.ToDictionary(k => k, k => (IEnumerable<string>)context.ModelState[k].Errors.Select(e => e.ErrorMessage).ToList());
throw new ValidationException(failures);
};
})
.AddFluentValidation(fv => fv.RegisterValidatorsFromAssemblyContaining<IWebApiDbContext>());
The failures object contains one error which says:
The input does not contain any JSON tokens. Expected the input to start with a valid JSON token, when isFinalBlock is true. Path: $ | LineNumber: 0 | BytePositionInLine: 0.
Here is a screenshot: Visual Studio in Debugging mode with json error.
In one article in stackoverflow I've read, that removing the [ApiController] class attribute can result in a more detailed error description. During debugging again the test and setting a breakpoint int the Update method from the FavoriteController at the line with await Mediator.Send(command);, I was able to see, that the command object arriving the Update method contains only null or default values, except the id, which was 5.
command
Caption null string
FavoriteName null string
Id 5 long
Public false bool
The most confusing (and frustrating) part is, that a manual test with swagger or postman are both successfull. The way I understand it, there has to be a problem during the integration test.
I hope, someone can help me and see what I'm missing. Could it be possible that there is something wrong with the HttpClient of the Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory?
We've found the problem in our LoggingMiddleware of the web api presentation project.
Before writing this question, we already hat a look at another article on stackoverflow:
ASP.NET MVC Core 3.0 - Why API Request from body keeps returning !ModelState.IsValid?
But we already had the request.Body.Seek(0, SeekOrigin.Begin); in our code. So, we thought that's it and it couldn't be the problem.
But now, we've found this article:
.net core 3.0 logging middleware by pipereader
Instead of reading the request body like this:
await request.Body.ReadAsync(buffer, 0, buffer.Length);
... where the stream is closed after read, we're using now the BodyReader as a stream and leave the stream open:
var stream = request.BodyReader.AsStream(true); // AsStream(true) to let stream open
await stream.ReadAsync(buffer, 0, buffer.Length);
request.Body.Seek(0, SeekOrigin.Begin);
So i have this ASP.NET Core on my local machine, i have installed the prerequisites and after running the application locally, the response was correct from the web browset that it was not found.
Okay, i am trying to invoked this API via Postman and i couldnt determine why i cant access it though i already checked the routings.
Below is the sample template
[HttpGet]
[Route("Details")]
public async Task<IActionResult> GetDetails(string value = null)
{
var response = new ListModelResponse<SomeModel>() as IListModelResponse<SomeModel>;
try
{
response.Model = await GetDetailsRepository
.GetDetailsSS(value)
.Select(item => item.ToViewModel())
.OrderBy(item => item.Name)
.ToListAsync();
}
catch (Exception ex)
{
response.DidError = true;
response.ErrorMessage = ex.Message;
}
return response.ToHttpResponse();
}
And in application insights of visual studio, i can see that it is invoking the API but it seems it can't get through.
Check this insights snippet
Other API's are working fine, it seems that i am missed something that i can't figure out right now.
For the routing i have this.
[Route("api/[controller]")]
I have also checked the Token and as i parsed it, i am getting the required info to access this API.
Thanks Lads!
It doesn't seem that you have the name of the controller in the request url.
api/[controller]/Details?value=CAT...
This error is due to the incorrect url present in the request. The correct URL has to be https://localhost:44309/api/your-controller-name/Details?value=CAT
ie. If the Controller name is ProductsController, then the URL has to be https://localhost:44309/api/Products/Details?value=CAT.
[Route("api/[controller]")]
public class ProductsController : Controller
{
[HttpPost("Details")]
public async Task<IActionResult> GetDetails(string value = null)
{
...
}
}
I'm developing an ASP.Net Core web application where I need to create a kind of "authentication proxy" to another (external) web service.
What I mean by authentication proxy is that I will receive requests through a specific path of my web app and will have to check the headers of those requests for an authentication token that I'll have issued earlier, and then redirect all the requests with the same request string / content to an external web API which my app will authenticate with through HTTP Basic auth.
Here's the whole process in pseudo-code
Client requests a token by making a POST to a unique URL that I sent him earlier
My app sends him a unique token in response to this POST
Client makes a GET request to a specific URL of my app, say /extapi and adds the auth-token in the HTTP header
My app gets the request, checks that the auth-token is present and valid
My app does the same request to the external web API and authenticates the request using BASIC authentication
My app receives the result from the request and sends it back to the client
Here's what I have for now. It seems to be working fine, but I'm wondering if it's really the way this should be done or if there isn't a more elegant or better solution to this? Could that solution create issues in the long run for scaling the application?
[HttpGet]
public async Task GetStatement()
{
//TODO check for token presence and reject if issue
var queryString = Request.QueryString;
var response = await _httpClient.GetAsync(queryString.Value);
var content = await response.Content.ReadAsStringAsync();
Response.StatusCode = (int)response.StatusCode;
Response.ContentType = response.Content.Headers.ContentType.ToString();
Response.ContentLength = response.Content.Headers.ContentLength;
await Response.WriteAsync(content);
}
[HttpPost]
public async Task PostStatement()
{
using (var streamContent = new StreamContent(Request.Body))
{
//TODO check for token presence and reject if issue
var response = await _httpClient.PostAsync(string.Empty, streamContent);
var content = await response.Content.ReadAsStringAsync();
Response.StatusCode = (int)response.StatusCode;
Response.ContentType = response.Content.Headers.ContentType?.ToString();
Response.ContentLength = response.Content.Headers.ContentLength;
await Response.WriteAsync(content);
}
}
_httpClient being a HttpClient class instantiated somewhere else and being a singleton and with a BaseAddressof http://someexternalapp.com/api/
Also, is there a simpler approach for the token creation / token check than doing it manually?
If anyone is interested, I took the Microsoft.AspNetCore.Proxy code and made it a little better with middleware.
Check it out here: https://github.com/twitchax/AspNetCore.Proxy. NuGet here: https://www.nuget.org/packages/AspNetCore.Proxy/. Microsoft archived the other one mentioned in this post, and I plan on responding to any issues on this project.
Basically, it makes reverse proxying another web server a lot easier by allowing you to use attributes on methods that take a route with args and compute the proxied address.
[ProxyRoute("api/searchgoogle/{query}")]
public static Task<string> SearchGoogleProxy(string query)
{
// Get the proxied address.
return Task.FromResult($"https://www.google.com/search?q={query}");
}
I ended up implementing a proxy middleware inspired by a project in Asp.Net's GitHub.
It basically implements a middleware that reads the request received, creates a copy from it and sends it back to a configured service, reads the response from the service and sends it back to the caller.
This post talks about writing a simple HTTP proxy logic in C# or ASP.NET Core. And allowing your project to proxy the request to any other URL. It is not about deploying a proxy server for your ASP.NET Core project.
Add the following code anywhere of your project.
public static HttpRequestMessage CreateProxyHttpRequest(this HttpContext context, Uri uri)
{
var request = context.Request;
var requestMessage = new HttpRequestMessage();
var requestMethod = request.Method;
if (!HttpMethods.IsGet(requestMethod) &&
!HttpMethods.IsHead(requestMethod) &&
!HttpMethods.IsDelete(requestMethod) &&
!HttpMethods.IsTrace(requestMethod))
{
var streamContent = new StreamContent(request.Body);
requestMessage.Content = streamContent;
}
// Copy the request headers
foreach (var header in request.Headers)
{
if (!requestMessage.Headers.TryAddWithoutValidation(header.Key, header.Value.ToArray()) && requestMessage.Content != null)
{
requestMessage.Content?.Headers.TryAddWithoutValidation(header.Key, header.Value.ToArray());
}
}
requestMessage.Headers.Host = uri.Authority;
requestMessage.RequestUri = uri;
requestMessage.Method = new HttpMethod(request.Method);
return requestMessage;
}
This method covert user sends HttpContext.Request to a reusable HttpRequestMessage. So you can send this message to the target server.
After your target server response, you need to copy the responded HttpResponseMessage to the HttpContext.Response so the user's browser just gets it.
public static async Task CopyProxyHttpResponse(this HttpContext context, HttpResponseMessage responseMessage)
{
if (responseMessage == null)
{
throw new ArgumentNullException(nameof(responseMessage));
}
var response = context.Response;
response.StatusCode = (int)responseMessage.StatusCode;
foreach (var header in responseMessage.Headers)
{
response.Headers[header.Key] = header.Value.ToArray();
}
foreach (var header in responseMessage.Content.Headers)
{
response.Headers[header.Key] = header.Value.ToArray();
}
// SendAsync removes chunking from the response. This removes the header so it doesn't expect a chunked response.
response.Headers.Remove("transfer-encoding");
using (var responseStream = await responseMessage.Content.ReadAsStreamAsync())
{
await responseStream.CopyToAsync(response.Body, _streamCopyBufferSize, context.RequestAborted);
}
}
And now the preparation is complete. Back to our controller:
private readonly HttpClient _client;
public YourController()
{
_client = new HttpClient(new HttpClientHandler()
{
AllowAutoRedirect = false
});
}
public async Task<IActionResult> Rewrite()
{
var request = HttpContext.CreateProxyHttpRequest(new Uri("https://www.google.com"));
var response = await _client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, HttpContext.RequestAborted);
await HttpContext.CopyProxyHttpResponse(response);
return new EmptyResult();
}
And try to access it. It will be proxied to google.com
A nice reverse proxy middleware implementation can also be found here: https://auth0.com/blog/building-a-reverse-proxy-in-dot-net-core/
Note that I replaced this line here
requestMessage.Content?.Headers.TryAddWithoutValidation(header.Key, header.Value.ToArray());
with
requestMessage.Headers.TryAddWithoutValidation(header.Key, header.Value.ToString());
Original headers (e.g. like an authorization header with a bearer token) would not be added without my modification in my case.
I had luck using twitchax's AspNetCore.Proxy NuGet package, but could not get it to work using the ProxyRoute method shown in twitchax's answer. (Could have easily been a mistake on my end.)
Instead I defined the mapping in Statup.cs Configure() method similar to the code below.
app.UseProxy("api/someexternalapp-proxy/{arg1}", async (args) =>
{
string url = "https://someexternalapp.com/" + args["arg1"];
return await Task.FromResult<string>(url);
});
Piggy-backing on James Lawruk's answer https://stackoverflow.com/a/54149906/6596451 to get the twitchax Proxy attribute to work, I was also getting a 404 error until I specified the full route in the ProxyRoute attribute. I had my static route in a separate controller and the relative path from Controller's route was not working.
This worked:
public class ProxyController : Controller
{
[ProxyRoute("api/Proxy/{name}")]
public static Task<string> Get(string name)
{
return Task.FromResult($"http://www.google.com/");
}
}
This does not:
[Route("api/[controller]")]
public class ProxyController : Controller
{
[ProxyRoute("{name}")]
public static Task<string> Get(string name)
{
return Task.FromResult($"http://www.google.com/");
}
}
Hope this helps someone!
Twitchax's answer seems to be the best solution at the moment. In researching this, I found that Microsoft is developing a more robust solution that fits the exact problem the OP was trying to solve.
Repo: https://github.com/microsoft/reverse-proxy
Article for Preview 1 (they actually just released prev 2): https://devblogs.microsoft.com/dotnet/introducing-yarp-preview-1/
From the Article...
YARP is a project to create a reverse proxy server. It started when we noticed a pattern of questions from internal teams at Microsoft who were either building a reverse proxy for their service or had been asking about APIs and technology for building one, so we decided to get them all together to work on a common solution, which has become YARP.
YARP is a reverse proxy toolkit for building fast proxy servers in .NET using the infrastructure from ASP.NET and .NET. The key differentiator for YARP is that it is being designed to be easily customized and tweaked to match the specific needs of each deployment scenario. YARP plugs into the ASP.NET pipeline for handling incoming requests, and then has its own sub-pipeline for performing the steps to proxy the requests to backend servers. Customers can add additional modules, or replace stock modules as needed.
...
YARP works with either .NET Core 3.1 or .NET 5 preview 4 (or later). Download the preview 4 (or greater) of .NET 5 SDK from https://dotnet.microsoft.com/download/dotnet/5.0
More specifically, one of their sample apps implements authentication (as for the OP's original intent)
https://github.com/microsoft/reverse-proxy/blob/master/samples/ReverseProxy.Auth.Sample/Startup.cs
Here is a basic implementation of Proxy library for ASP.NET Core:
This does not implement the authorization but could be useful to someone looking for a simple reverse proxy with ASP.NET Core. We only use this for development stages.
using System;
using System.Globalization;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Primitives;
namespace Sample.Proxy
{
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddLogging(options =>
{
options.AddDebug();
options.AddConsole(console =>
{
console.IncludeScopes = true;
});
});
services.AddProxy(options =>
{
options.MessageHandler = new HttpClientHandler
{
AllowAutoRedirect = false,
UseCookies = true
};
options.PrepareRequest = (originalRequest, message) =>
{
var host = GetHeaderValue(originalRequest, "X-Forwarded-Host") ?? originalRequest.Host.Host;
var port = GetHeaderValue(originalRequest, "X-Forwarded-Port") ?? originalRequest.Host.Port.Value.ToString(CultureInfo.InvariantCulture);
var prefix = GetHeaderValue(originalRequest, "X-Forwarded-Prefix") ?? originalRequest.PathBase;
message.Headers.Add("X-Forwarded-Host", host);
if (!string.IsNullOrWhiteSpace(port)) message.Headers.Add("X-Forwarded-Port", port);
if (!string.IsNullOrWhiteSpace(prefix)) message.Headers.Add("X-Forwarded-Prefix", prefix);
return Task.FromResult(0);
};
});
}
private static string GetHeaderValue(HttpRequest request, string headerName)
{
return request.Headers.TryGetValue(headerName, out StringValues list) ? list.FirstOrDefault() : null;
}
public void Configure(IApplicationBuilder app)
{
app.UseWebSockets()
.Map("/api", api => api.RunProxy(new Uri("http://localhost:8833")))
.Map("/image", api => api.RunProxy(new Uri("http://localhost:8844")))
.Map("/admin", api => api.RunProxy(new Uri("http://localhost:8822")))
.RunProxy(new Uri("http://localhost:8811"));
}
public static void Main(string[] args)
{
var host = new WebHostBuilder()
.UseKestrel()
.UseIISIntegration()
.UseStartup<Startup>()
.Build();
host.Run();
}
}
}