Add an extension method to add Dapr HTTP Client to service collection

Describe the proposal

Currently, we can call the CreateInvokeHttpClient from DaprClient to create a preconfigured HttpClient. It would be great to leverage the IHttpClientFactory of ASP.NET Core with the same level of integration as the CreateInvokeHttpClient.

In short, there’s how it could be used :

services.AddDaprHttpClient<CartClient, CartClient>("appId");

I’ve created a PR to see how it could be implemented.

[jkears]

@rynowak Actually I got it to work based upon your example…

namespace NextWare.Domain.Gateway.DependencyInjection
{
    public static class EndPointConfiguration
    {
        public static IServiceCollection AddEndPoints(this IServiceCollection services, ConfigurationManager configuration)
        {

            // Non-Dapr
            //services.AddHttpClient(WellKnownSchemaNames.OrderServices, c => c.BaseAddress = new Uri(configuration.GetConnectionString("OrderServices"))).AddHeaderPropagation();
            //services.AddHttpClient(WellKnownSchemaNames.InventoryServices, c => c.BaseAddress = new Uri(configuration.GetConnectionString("InventoryServices"))).AddHeaderPropagation();

            // With-Dapr
            services.AddHttpClient(WellKnownSchemaNames.OrderServices, c =>
            {
                c.BaseAddress = new Uri($"http://{WellKnownSchemaNames.OrderServices}");
            }).AddHttpMessageHandler(() => new InvocationHandler()).AddHeaderPropagation();

            services.AddHttpClient(WellKnownSchemaNames.InventoryServices, c =>
            {
                c.BaseAddress = new Uri($"http://{WellKnownSchemaNames.InventoryServices}");
            }).AddHttpMessageHandler(() => new InvocationHandler()).AddHeaderPropagation();
 
            return services;
        }
    }
}

Very simple so thank you!

[karoldeland]

Hi @rynowak, I have to agree with you. I realized yesterday while implementing the basic method that it will imply to have a lot of code to support all overloads.

For me, the need was mainly a concern of adopting the best-practices for ASP.NET about the IHttpClientFactory. It will be useful to have the possibility to add global policies like retries, but it seems that Dapr will solve this early soon. So I think it’s not a good idea to add code in the SDK that have high chance to be useless in the short term.

IMHO, the second sample you provide is nice. I personaly don’t like to have http:// strings in the code.

For sure, adding this to documentation would be a great addition.