Having dynamic proxy with HttpClientFactory implementation

Question

I have Asp.Net Core WebApi. I am making Http requests according to HttpClientFactory pattern. Here is my sample code:

public void ConfigureServ         


        

Answer 1

I can do that by inheriting from HttpClientHandler:

public class ProxyHttpHandler : HttpClientHandler
{
    private int currentProxyIndex = 0;

private ProxyOptions proxyOptions;

public ProxyHttpHandler(IOptions options)
{
    proxyOptions = options != null ? options.Value : throw new ArgumentNullException(nameof(options));
    UseProxy = true;
}

protected override Task SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
    var proxy = proxyOptions.Proxies[currentProxyIndex];
    var proxyResolver = new WebProxy(proxy.Host, proxy.Port)
    {
        Credentials = proxy.Credentials
    };

    Proxy = proxyResolver;

    currentProxyIndex++;
    if(currentProxyIndex >= proxyOptions.Proxies.Count)
        currentProxyIndex = 0;

    return base.SendAsync(request, cancellationToken);
}

}

Then I register my ProxyHttpHandler and ProxyOptions in IoC:

public IForksCoreConfigurationBuilder ConfigureProxy(Action options)
{
    Services.AddOptions().Configure(options);
    Services.AddTransient();
    Services.AddHttpClient()
            .ConfigurePrimaryHttpMessageHandler();

    return this;
}