ExceptionFilter example

ExceptionFilter.cs

namespace SiteApi.Filters {
	public class ExceptionFilter : IAsyncExceptionFilter {
		private readonly IHostingEnvironment _hostingEnvironment;

		public ExceptionFilter(IHostingEnvironment hostingEnvironment) {
			_hostingEnvironment = hostingEnvironment;
		}

		public async Task OnExceptionAsync(ExceptionContext context) {
			context.ExceptionHandled = false;
			var requestInfos = await GetRequestInfos(context.HttpContext?.Request);

			_ = RollbarLocator.RollbarInstance.Error(context.Exception, requestInfos);

			if (_hostingEnvironment.IsProduction()) {
				context.Result = new NotFoundResult();
			}
		}

		private async Task<Dictionary<string, object>> GetRequestInfos(HttpRequest request) {
			if (request == null) {
				return new Dictionary<string, object> { { "additionalInfo", "Отсутствует контекст вызова HttpRequest" } };
			}

			var requestData = new Dictionary<string, object> {
										{ "path", request.Path },
										{ "query", request.Query },
										{ "queryString", request.QueryString },
										{ "method", request.Method },
										{ "contentType", request.ContentType } };

			if (request.Headers != null) {
				foreach (var item in request.Headers) {
					requestData.TryAdd(item.Key, item.Value);
				}
			}

			if (request.Method?.ToLowerInvariant() == "post" && request.Body != null) {
				string body = "No json data.";

				if (request.ContentType == "application/json") {
					try {
						using (var sr = new StreamReader(request.Body)) {
							if (sr.BaseStream.CanRead && sr.BaseStream.CanSeek) {
								request.Body.Seek(0, SeekOrigin.Begin);
								body = await sr.ReadToEndAsync();
							}
						}
					} catch { /*что бы не упасть там где падать совсем не следует */}
				}
				if (!requestData.TryAdd("requestBody", body)) { 
					requestData["requestBody"] = body;
				}
			}

			return requestData;
		}
	}
}