public async Task Invoke(HttpContext context, IBeatPulseService pulseService) { var request = context.Request; if (!IsBeatPulseRequest(request, out string beatPulsePath)) { await _next.Invoke(context); return; } if (!await IsAuthenticatedRequest(context)) { context.Response.StatusCode = StatusCodes.Status401Unauthorized; return; } if (TryFromCache(beatPulsePath, out OutputLivenessMessage output)) { await request.HttpContext .Response .WriteLivenessMessage(_options, output); return; } output = new OutputLivenessMessage(); var responses = await pulseService.IsHealthy(beatPulsePath, _options, context); if (!responses.Any()) { // beat pulse path is not valid across any liveness // return unavailable with not found reason. output.SetNotFound(); } else { // beat pulse is executed, set response // messages and add to cache if is configured. output.AddHealthCheckMessages(responses); output.SetExecuted(); if (_options.CacheMode.UseServerMemory() && _options.CacheOutput) { _cache.TryAdd(beatPulsePath, output); } } await request.HttpContext .Response .WriteLivenessMessage(_options, output); }
bool TryFromCache(string path, out OutputLivenessMessage message) { message = null; if (_options.CacheOutput && _options.CacheMode.UseServerMemory() && _cache.TryGetValue(path, out message)) { var seconds = (DateTime.UtcNow - message.EndAtUtc).TotalSeconds; if (_options.CacheDuration > seconds) { return(true); } else { _cache.TryRemove(path, out OutputLivenessMessage removed); return(false); } } return(false); }
public static Task WriteLivenessMessage(this HttpResponse response, BeatPulseOptions options, OutputLivenessMessage message) { var defaultContentType = options.DetailedOutput ? "application/json" : "text/plain"; const string noCacheOptions = "no-cache, no-store, must-revalidate"; const string noCachePragma = "no-cache"; const string defaultExpires = "0"; response.Headers["Content-Type"] = new[] { defaultContentType }; if (options.CacheOutput) { if (options.CacheMode == CacheMode.Header || options.CacheMode == CacheMode.HeaderAndServerMemory) { response.Headers["Cache-Control"] = new[] { $"public, max-age={options.CacheDuration}" }; } } else { response.Headers["Cache-Control"] = new[] { noCacheOptions }; response.Headers["Pragma"] = new[] { noCachePragma }; response.Headers["Expires"] = new[] { defaultExpires }; } response.StatusCode = message.Code; var content = options.DetailedOutput ? JsonConvert.SerializeObject(message) : Enum.GetName(typeof(HttpStatusCode), message.Code); return(response.WriteAsync(content)); }