Who can help me? using YARP in an ApiController. Thanks Very much!

[AtlantisDe]

Who can help me? using YARP in an ApiController. Thanks Very much!

Who can help me? I need to implement traffic distribution using YARP in an ApiController. The logic for this needs to be written in my own code. Additionally, I need to adapt the parameters sent by users.

For example, in an ApiController's api/TestReverseProxy, I need to implement different reverse proxy scenarios. I need to handle custom request information, such as adding the request header parameter "Content-Type": "application/x-www-form-urlencoded".

Request targets:

• Case 1: https://example111.com/api/test?aaa={Custom parameters}
• Case 2: https://example222.com/api/testTwo?bbb={Custom parameters}

Finally, I need to handle the returned result before sending it to the user.

ApiController -- need to

• I need to implement here....

    [Route("api/[controller]")]
    [ApiController]
    public class TestController : ControllerBase
    {
        private readonly IHttpClientFactory _httpClientFactory;

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

        [HttpGet]
        public async Task<IActionResult> Get()
        {
            var targetUri = new Uri("https://example111.com/api/test?aaa={Custom parameters}" + HttpContext.Request.Path + HttpContext.Request.QueryString);

            // Case 1: https://example111.com/api/test?aaa={Custom parameters}
            // Case 2: https://example222.com/api/testTwo?bbb={Custom parameters}

            // http IReverseProxyFeature

          //  var response = 

            return Ok(response);
        }
    }

ApiController --- by ChatGPT

• This is an example code provided by ChatGPT, but the code is incorrect and cannot run successfully.

    [ApiController]
    [Route("api/[controller]")]
    public class MyController : ControllerBase
    {
        private readonly IHttpClientFactory _httpClientFactory;

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

        [HttpGet("{id}")]
        public async Task<IActionResult> Get(int id, [FromServices] IReverseProxyFeature reverseProxyFeature)
        {
            // Dynamically set the target server address based on your logic
            var targetServerAddress = "https://example111.com/api/test?aaa={Custom parameters}";

            var httpClient = _httpClientFactory.CreateClient();

            // Use IReverseProxyFeature to set the target server address
            var reverseProxyHttpContextFeature = HttpContext.Features.Get<IReverseProxyFeature>();
            if (reverseProxyHttpContextFeature != null)
            {

                reverseProxyHttpContextFeature.ProxiedDestination = new DestinationState(targetServerAddress);
            }

            // Make the request
            var response = await httpClient.GetAsync($"/api/order?pid=1&t=1699843081{id}");

            if (response.IsSuccessStatusCode)
            {
                // Process the successful response
                var content = await response.Content.ReadAsStringAsync();
                return Ok(content);
            }
            else
            {
                // Handle the error response
                return StatusCode((int)response.StatusCode, response.ReasonPhrase);
            }
        }
    }

[Tratcher]

Start with the examples here: https://microsoft.github.io/reverse-proxy/articles/direct-forwarding.html

While it shows code in Startup and Map, most of that can be moved to a controller as well. Just be careful about the lifetime of the httpClient, you don't want to create a new one per request. You can store it in a static field.

I need to handle custom request information, such as adding the request header parameter "Content-Type": "application/x-www-form-urlencoded".

Is this a GET or POST request? Does it already have a Content-Type? You wouldn't usually just add/change the Content-Type header, you'd have to replace the contents of the request body as well. See https://microsoft.github.io/reverse-proxy/articles/transforms.html#request-body-transforms

This is an example code provided by ChatGPT, but the code is incorrect and cannot run successfully.

LOL, none of that is right. I guess my job is safe for another day.