HTTP Listener in a HTTP Trigger Azure Function - azure

Question

I have a HTTP Listener console app that works on my local machine. When I try to use it inside a HTTP Trigger Azure Function. I always get the 418 error code.
In my console app:
HttpListener listener = new HttpListener();
try
{
listener.Prefixes.Add("http://localhost:11000/");
listener.Start();
} catch (Exception e)
{ // }
do {
var ctx = listener.GetContext();
var res = ctx.Response;
var req = ctx.Request;
var reqUrl = req.Url;
var readStream = new StreamReader(req.InputStream);
var content = readStream.ReadToEnd();
Console.WriteLine(content);
// business logic
readStream.Close();
res.StatusCode = (int)HttpStatusCode.OK;
res.ContentType = "text/plain";
res.OutputStream.Write(new byte[] { }, 0, 0);
res.Close();
if (stopListener) { listener.Stop(); }
} while (listener.IsListening);
Now HTTP Trigger Function uses the HttpRequest class and that seems to give me the 418 error code. I replaced it with HttpListener() but when I add the prefix of the Azure Function string connection (on the CLI), the stream never goes through and its as if its not capturing it? Or what connection should I use? I feel like self-referencing it is the reason its not working.
Azure Function:
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpListener listener,
ILogger log,
IBinder binder)
{//same as above}
Is this the right approach to getting data from an external app? So far this has been the way I can see it working via the HTTP Listener.
Any suggestions are welcomed.

Answer 1

Is this the right approach to getting data from an external app?
The right way to access Data from an external source and any other source. You can create an API and use this API to access data from external sources.
For create azure function click hereby Microsoft documents.
Below sample code for access web API in azure function.
var _httpclient = new HttpClient();
var _response = await _httpclient .GetAsync(rul);
var result_= await _response .Content.ReadAsStringAsync();
its use is just like using API in C# code.
Azure Function Code:-
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System.Net.Http;
namespace _73093902_FunctionApp10
{
public static class Function1
{
[FunctionName("Function1")]
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
ILogger log)
{
var _httpclient = new HttpClient();
var _response = await _httpclient.GetAsync("https://localhost:7101/WeatherForecast");
var result_ = await _response.Content.ReadAsStringAsync();
return new OkObjectResult(result_);
}
}
}
Debug Output:-