HttpGet IActionResult method calling microservice returns all attributes as null

Question

I'm following this tutorial and specifically using the code from the Basic Usage section.

When I send a GET request from Postman to http://localhost:9000/api/gateway, I get the right number of objects, as many as are in the database, but all attributes as null.

I tried changing the ReadAsStreamAsync to ReadAsStringAsync, and I actually got one big string, an array of all the records from the database.

The attributes were NOT null there, but I don't know how to parse a string into an IEnumerable of objects, so that doesn't help me much.

Anybody have an idea what I could be missing? See the controller method below.

Note that the method sends HTTP requests to localhost:5000, but the method itself receives incoming requests on localhost:9000.

The goal is to create an API Gateway, that calls another microservice and is not supposed to have a direct access to the database of the microservice it is calling.

public async Task<IActionResult> GetAllPatientsAsync()
    {
        var httpRequestMessage = new HttpRequestMessage(
HttpMethod.Get, "http://localhost:5000/api/patients")
        {
            Headers =
        {
            { HeaderNames.Accept, "application/json" }
        }
        };
        var httpClient = httpClientFactory.CreateClient();
        var httpResponseMessage = await httpClient.SendAsync(httpRequestMessage);

        if (httpResponseMessage.IsSuccessStatusCode)
        {
            using var contentStream =
                await httpResponseMessage.Content.ReadAsStreamAsync();
            PatientDtos = await JsonSerializer.DeserializeAsync
                <IEnumerable<PatientDto>>(contentStream);                

        }


        if (PatientDtos == null) return NotFound(); // 404 Not Found

        return Ok(PatientDtos);
    }

Answer 1

Turns out it was a problem with JsonSerializer. The following changes did the trick for me:

PatientDtos = await JsonSerializer.DeserializeAsync<IEnumerable<PatientDto>>(
 contentStream, new JsonSerializerOptions
 {
   PropertyNamingPolicy = JsonNamingPolicy.CamelCase
 });

More information here.