Authentication per request using HttpClientFactory .net Core 2.1

Question

How should I use HttpClientFactory to return an instance of HttpClient whose uri and credentials are determined at the point of the call?

The existing code looks like this:

var httpClientHandler = new HttpClientHandler()
    {
        Credentials = new NetworkCredential(userName, password),
    };
HttpClient client = new HttpClient(httpClientHandler);
client.BaseAddress = new Uri(_appSetting.ServiceURI);

Answer 1

your ConfigureServices method in Start up class

             services.AddHttpClient("github", c =>
            {
                //c.BaseAddress = new Uri("https://api.github.com/");
                c.DefaultRequestHeaders.Add("Accept", "application/vnd.github.v3+json");
                c.DefaultRequestHeaders.Add("User-Agent", "HttpClientFactory-Sample");
                
            }).ConfigurePrimaryHttpMessageHandler(() =>
            {
                return new HttpClientHandler()
                {
                    UseDefaultCredentials = true,
                    Credentials = new NetworkCredential("", ""),
                };
            });

Your Controller will look like this

 private readonly IHttpClientFactory _httpClientFactory;

        public DataProController(IHttpClientFactory httpClientFactory)
        {
            _httpClientFactory = httpClientFactory;
        }

        [HttpGet]
        public async Task<ActionResult> Get()
        {            
            var client = _httpClientFactory.CreateClient("github");
            
            client.BaseAddress = new Uri("https://api.github.com/");

            string result = await client.GetStringAsync("/");
            return Ok(result);
        }

You may not be able to set up Network Credentials at the run time when using httpclientfactory and may need to setup up in the startup class. you can find about this issue here. https://github.com/aspnet/HttpClientFactory/issues/71