private void GetEventInfoFromAttribute(CustomEventRequest customEvent)
{
// walk up the stack and check for our EventGridSinkAttribute
var st = new StackTrace();
var stackFrames = st.GetFrames();
if (stackFrames == null)
{
return;
}
var methods = stackFrames.Where(f => f != null).Select(f => f.GetMethod()).ToArray();
// walk through serilog to reach the calling method
var callingMethod = methods.FirstOrDefault(m => !m?.DeclaringType?.FullName?.StartsWith("Serilog") ?? false) ?? methods.First();
var subjectAttributeValue = GetCustomValueFromAttribute <EventGridSubjectAttribute>(methods);
var typeAttributeValue = GetCustomValueFromAttribute <EventGridTypeAttribute>(methods);
// assign the event info, failing back to generic defaults
customEvent.Subject = customEvent.Subject ?? subjectAttributeValue ?? GetSubject();
customEvent.EventType = customEvent.EventType ?? typeAttributeValue ?? _customEventType ?? GetEventType() ?? "AppDomain/Class";
string GetSubject()
{
var methodName = GetMethodWithParams() ?? "Method/default";
return($"{methodName}");
}
string GetMethodWithParams()
{
var parameterNames = callingMethod != null && callingMethod.GetParameters().Any()
? callingMethod.GetParameters().Select(x => x.Name).Aggregate((combined, next) => combined += string.IsNullOrEmpty(combined) ? next : $"/{next}")
: "default";
var methodWithParameters = $"{callingMethod?.Name}/{parameterNames}";
return(methodWithParameters);
}
string GetEventType()
{
var assemblyName = callingMethod?.ReflectedType?.Assembly.GetName().Name ?? "General";
var className = callingMethod?.ReflectedType?.Name ?? "Class";
return($"{assemblyName}/{className}");
}
}
public async Task SendEvent(LogEvent logEvent)
{
// make a dictionary from the log event properties
var props = logEvent.Properties
.Select(pv => new { Name = pv.Key, Value = EventGridPropertyFormatter.Simplify(pv.Value) })
.ToDictionary(a => a.Name, b => b.Value);
// build the request from sink config and log event properties
var customEvent = new CustomEventRequest
{
Subject = _customEventSubject ?? GetEventSubjectFromProperties(props),
EventType = _customEventType ?? GetEventTypeFromProperties(props)
};
// if we don't have what we need from the config or the event, pull event info from the call stack
if (string.IsNullOrEmpty(customEvent.Subject) || string.IsNullOrEmpty(customEvent.EventType))
{
GetEventInfoFromAttribute(customEvent);
}
// add log severity information
props.Add("Severity", logEvent.Level.ToString());
// clean up the payload
props.Add("LogMessage", logEvent.MessageTemplate.Render(logEvent.Properties));
customEvent.Data = props.Where(p => p.Key != _customSubjectPropertyName && p.Key != _customTypePropertyName);
// finally, we have what we need post the event
var client = new HttpClient();
var request = new HttpRequestMessage(HttpMethod.Post, _topicUri);
request.Headers.Add(_customEventRequestAuth == CustomEventRequestAuth.Key ? "aeg-sas-key" : "aeg-sas-token", _key);
var body = new[] { customEvent };
var json = JsonConvert.SerializeObject(body, Newtonsoft.Json.Formatting.Indented, new JsonSerializerSettings
{
NullValueHandling = NullValueHandling.Ignore,
ContractResolver = new CamelCasePropertyNamesContractResolver()
});
request.Content = new StringContent(json);
await client.SendAsync(request);
}
