Specify Localhost Port for C# .NET Async / Await Requests in Visual Studio

Question

I am debugging a console application that uses Oauth2 credentials, and the service provider requires that I specify a redirect URI. I specify the redirect URI in the service provider's Web portal. The service is Google Analytics.

I have successfully tested the service with a Node.js application. In the service's configuration, I have specified a redirect URI of http://localhost:8080. The Node application actually starts on port 8080 by default, so I can simply run http-server, browse to http://localhost:8080, call the service, and see the response with data.

However, when I try to call the same service with a C# console application, I receive an HTTP 400 error in the browser. The error states:

The redirect URI in the request, http://localhost:59291/authorize/, does not match the ones authorized for the OAuth client.

Each time I try to run the application, the port changes. Here is the code (referenced from Analytics Reporting API V4 Client Library for .NET):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using Google.Apis.AnalyticsReporting.v4;
using Google.Apis.AnalyticsReporting.v4.Data;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;
using Google.Apis.Util.Store;
using System.Threading;

namespace Google_Analytics_API_Test
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                var credential = GetCredential().Result;
                using (var svc = new AnalyticsReportingService(
                    new BaseClientService.Initializer
                    {
                        HttpClientInitializer = credential,
                        ApplicationName = "Google Analytics API Console"
                    }))
                {
                    var dateRange = new DateRange
                    {
                        StartDate = "2017-04-24",
                        EndDate = "today"
                    };
                    var sessions = new Metric
                    {
                        Expression = "ga:sessions",
                        Alias = "Sessions"
                    };
                    var date = new Dimension { Name = "ga:date" };

                    var reportRequest = new ReportRequest
                    {
                        DateRanges = new List<DateRange> { dateRange },
                        Dimensions = new List<Dimension> { date },
                        Metrics = new List<Metric> { sessions },
                        ViewId = "<<viewID>>"
                    };

                    var getReportsRequest = new GetReportsRequest
                    {
                        ReportRequests = new List<ReportRequest> {    reportRequest }
                    };
                    var batchRequest =    svc.Reports.BatchGet(getReportsRequest);
                    var response = batchRequest.Execute();
                    foreach (var x in response.Reports.First().Data.Rows)
                    {
                        Console.WriteLine(string.Join(",", x.Dimensions) +
                            " " + string.Join(", ",    x.Metrics.First().Values));
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }

            static async Task<UserCredential> GetCredential()
            {
                using (var stream = new FileStream("client_secret.json",
                    FileMode.Open, FileAccess.Read))
                {
                    const string loginEmailAddress = "<<emailAddress>>";
                return await GoogleWebAuthorizationBroker.AuthorizeAsync(
                    GoogleClientSecrets.Load(stream).Secrets,
                    new[] { AnalyticsReportingService.Scope.Analytics },
                    loginEmailAddress, CancellationToken.None,
                    new FileDataStore("GoogleAnalyticsApiConsole"));
                }
           }
       }
    }

I have searched for a way to configure IIS Express with a static port for debugging, but I'm not sure that IIS is even involved here - rather than just something like TcpClient / TcpListener objects that are implemented by the Google Analytics library?

Is there a way to specify a port for async / await requests in a C# .NET console application?

Answer 1

The issue here, obviously, is that your request is going out through an HttpClient; the Google.Apis.Http.HttpClientfactory returns this via ConfigurableHttpClient. The HttpClient does not expose the methods to the underlying ServicePoint to set the local bound IP address (more information at bottom)

The best way to resolve this is to make sure that you are using the Credentials in the correct manner. Since you are connecting from a Console application you can easily set these credentials to Other, which is in fact the preferred way. try looking at the "Create Credentials" button and select the "Help Me Choose", which can guide you through Scenarios. Otherwise, just create as below.

On the suggestion of @panagiotis-kanavos, I will add the clarification:

HttpClient does not expose access to ServicePoint. You could use reflection to access the underlying ServicePoint object. It may provide a resolution to your attempts to bind to a specifical local address if you do not want to use console API credentials withing Google API for Analytics

To do this, please examine this question: Use httpclient to send a request from a specific IP address

As far as I am aware, the BaseClientService will only allow you to set a custom HttpFactory or a custom HttpClientInitializer (modify post-create), so you would need to create your a custom HttpFactory instance returning the ConfigurableHttpClient modified as above.

1. GoogleApi HttpClientFactory
2. GoogleApi ConfigurableHttpClient

Once you've done that you pass your custom HttpClientFactory through.

 using (var svc = new AnalyticsReportingService(
     new BaseClientService.Initializer
 {
     HttpClientInitializer = credential,
     ApplicationName = "Google Analytics API Console",
     HttpClientFactory = new CustomHttpClientFactory()
 }))