fix(nodes): locate agents behind a proxy and retry missing countries [CI]

backend/fleet/src/Fleet.Server.Enrollment/FleetEnrollmentEndpoints.cs

@@ -73,7 +73,7 @@ public static class FleetEnrollmentEndpoints
             return Problem(StatusCodes.Status400BadRequest, FleetErrors.InvalidParams, "request body is not valid");
         }
 
-        Result<EnrollResponse> result = await service.EnrollAsync(request, http.Connection.RemoteIpAddress?.ToString(), http.RequestAborted);
+        Result<EnrollResponse> result = await service.EnrollAsync(request, ClientIp(http), http.RequestAborted);
         if (result.TryGet(out EnrollResponse? response, out FleetError? error))
         {
             return Results.Json(response, EnrollmentJsonContext.Default.EnrollResponse, statusCode: StatusCodes.Status201Created);
@@ -88,6 +88,11 @@ public static class FleetEnrollmentEndpoints
         return Problem(status, error.Code, error.Message);
     }
 
+    private static string? ClientIp(HttpContext http) =>
+        http.RequestServices.GetService<IClientAddressSource>() is { } source
+            ? source.Resolve(http.Connection.RemoteIpAddress, name => http.Request.Headers[name].Select(v => v ?? ""))
+            : http.Connection.RemoteIpAddress?.ToString();
+
     private static async Task<EnrollRequest?> ReadBodyAsync(HttpContext http, CancellationToken ct)
     {
         if (http.Request.ContentLength > MaxBodyBytes)