No connection could be made because the target machine actively refused it [http://127.0.0.1:8000/auth/login]

Question

I set up a fake json server (fake-api-jwt-json-server) taken from GitHub on my PC. Using url http://localhost:8000/auth/login, I am able to post to it successfully from Postman but when I tried from Visual Studio 2019, I got the error 'No connection could be made because the target machine actively refused it' (see error detail below). The same was the result when I tried another fake json server. In both cases, the url included 'http://localhost'. From VS, I am able to get responses from api endpoints that do not include 'http://localhost' with no problem. Why are the localhost api urls not working when I try them from VS? I have tried switching off my firewall.

The error message:-

jServerAGetAccessToken Source: Tests.cs line 27 Duration: 2.1 sec

Message: System.AggregateException : One or more errors occurred. (No connection could be made because the target machine actively refused it.) ----> System.Net.Http.HttpRequestException : No connection could be made because the target machine actively refused it. ----> System.Net.Sockets.SocketException : No connection could be made because the target machine actively refused it. Stack Trace: Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions) Task1.GetResultCore(Boolean waitCompletionNotification) Task1.get_Result() Tests.jServerAGetAccessToken() line 50 --HttpRequestException ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken) HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean allowHttp2, CancellationToken cancellationToken) HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken) HttpConnectionPool.GetHttpConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken) HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken) RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) HttpClient.FinishSendAsyncBuffered(Task1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts) HttpMethods.PostWithKey(Dictionary2 url, StringContent postParamaters) line 92 --SocketException ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)

And now my code:-

public async Task<string> PostWithKey(Dictionary<string, string> url, StringContent postParamaters)
    {
        using (HttpClient client = new HttpClient())
        {
            client.BaseAddress = new Uri(url["endpoint"]);
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            client.DefaultRequestHeaders.Add("Cache-Control", "no-cache");

            using (HttpResponseMessage response = await client.PostAsync(url["resource"] + url["paramaters"], postParamaters))
            {
                var strJson = response.Content.ReadAsStringAsync().Result;

                status = response.StatusCode.ToString();
                statusCode = (int)response.StatusCode;

                return strJson;
            }
        }
    }

Also,

[Test]
    public void jServerAGetAccessToken()
    {
        string jsonPath = NunitTestContext.CurrentContext.TestDirectory + @"..\..\..\..\Files\";
        var jsonFile = "LoginCredentials.json";

        Dictionary<string, string> postUrl = new Dictionary<string, string>()
        {
            { "endpoint", "http://127.0.0.1"},
            { "resource", ":8000/auth/login"},
            { "paramaters", ""},
            { "key", "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJlbWFpbCI6InRlY2hpZUBlbWFpbC5jb20iLCJwYXNzd29yZCI6InRlY2hpZSIsImlhdCI6MTYxMDYzNjYzNywiZXhwIjoxNjEwNjQwMjM3fQ.CW6adTp9PNT3oTiQVKSy3HHYZMimUM12V5aWUiyDPoc"}
        };

        Credentials jsonDeserialised = JsonConvert.DeserializeObject<Credentials>(File.ReadAllText(jsonPath + jsonFile));

        _credentials.email = jsonDeserialised.email;
        _credentials.password = jsonDeserialised.password;

        StringContent jsonData = new StringContent(JsonConvert.SerializeObject(_credentials), Encoding.UTF8, "application/json");

        var result = PostWithKey(postUrl, jsonData).Result;
        var response = JsonConvert.DeserializeObject<Credentials>(result);

        Assert.AreEqual("Created", status, "Status text is incorrect");
        Assert.AreEqual(201, statusCode, "Status text is incorrect");
    }

Martin Staufcik Martin Staufcik · Accepted Answer · 2021-01-17T18:16:23

Try changing the endpoint (base) address to include also the port to http://127.0.0.1:8000:

Dictionary<string, string> postUrl = new Dictionary<string, string>()
{
    { "endpoint", "http://127.0.0.1:8000"},
    { "resource", "auth/login"},
    { "paramaters", ""},
    { "key", "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJlbWFpbCI6InRlY2hpZUBlbWFpbC5jb20iLCJwYXNzd29yZCI6InRlY2hpZSIsImlhdCI6MTYxMDYzNjYzNywiZXhwIjoxNjEwNjQwMjM3fQ.CW6adTp9PNT3oTiQVKSy3HHYZMimUM12V5aWUiyDPoc"}
};

No connection could be made because the target machine actively refused it [http://127.0.0.1:8000/auth/login]

1 Answers