Pass username and password to authenticated proxy server when running locally only on IIS server. ASP core 2.0

Question

I am developing an application that will be deployed outside of the intranet(proxy server) but I am developing the application behind the proxy server. The proxy server uses http to authenticate and requires a username and password. Is there a way I can use my systems proxy credentials only when running(debugging) the app locally? The app is an ASP core 2.0 app. This is a snippet of a code I use: I want the httpClientHandler used when running debugging only when the application is deployed I don't need this since it's deployed out side of proxy server. How can I achieve this?

await new HttpClient(ProxyConfig.httpClientHandler).SendAsync(request).ConfigureAwait(false);
public class ProxyConfig
{
    public static WebProxy proxy = new WebProxy
    {
        Address = new Uri($"http://***.***.***.com:8080"),
        BypassProxyOnLocal = false,
        UseDefaultCredentials = false,
        Credentials = new NetworkCredential(userName: "****", password: "****")
    };
    public static HttpClientHandler httpClientHandler = new HttpClientHandler()
    {
        Proxy = proxy,
    };
}

Answer 1

I would suggest to register HttpClient on Startup file and inject it to your Controller or Service.

Checking the environment(IHostingEnvironment), depending on the environment you can register either HttpClient with a proxy handler or without a proxy handler. While you are working locally it should be Development where you can register the HttpClient with a proxy. Otherwise, you will be using the HttpClient instance without a proxy setting.

Here below sample code to register HttpClient:

public class Startup
{
    private readonly IHostingEnvironment hostingEnvironment;

    public Startup(IHostingEnvironment hostingEnvironment)
    {
        this.hostingEnvironment = hostingEnvironment;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc()
            .SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

        if(hostingEnvironment.IsDevelopment())
        {
            var httpClient = new HttpClient(new HttpClientHandler()
            {
                // Set your proxy details here
            });
            services.AddSingleton(httpClient);
        }
        else
        {
            services.AddSingleton<HttpClient, HttpClient>();
        }
    }        

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseMvc();
    }
}

And sample code to inject HttpClient to your Controller(likewise you can inject it to your Services):

[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
    private readonly HttpClient httpClient;

    public ValuesController(HttpClient httpClient)
    {
        this.httpClient = httpClient;
    }
}