namespace BuildingBlocks.Polly; using System.Net; using Ardalis.GuardClauses; using BuildingBlocks.Web; using global::Polly; using global::Polly.Extensions.Http; using Microsoft.Extensions.Configuration; using Microsoft.Extensions.DependencyInjection; using Microsoft.Extensions.Logging; public static class HttpClientRetry { // ref: https://anthonygiretti.com/2019/03/26/best-practices-with-httpclient-and-retry-policies-with-polly-in-net-core-2-part-2/ public static IHttpClientBuilder AddHttpClientRetryPolicyHandler(this IHttpClientBuilder httpClientBuilder) { return httpClientBuilder.AddPolicyHandler((sp, _) => { var options = sp.GetRequiredService().GetOptions(nameof(PolicyOptions)); Guard.Against.Null(options, nameof(options)); var loggerFactory = sp.GetRequiredService(); var logger = loggerFactory.CreateLogger("PollyHttpClientRetryPoliciesLogger"); return HttpPolicyExtensions.HandleTransientHttpError() .OrResult(msg => msg.StatusCode == HttpStatusCode.BadRequest) .OrResult(msg => msg.StatusCode == HttpStatusCode.InternalServerError) .WaitAndRetryAsync(retryCount: options.Retry.RetryCount, sleepDurationProvider: retryAttempt => TimeSpan.FromSeconds(options.Retry.SleepDuration), onRetry: (response, timeSpan, retryCount, context) => { if (response?.Exception != null) { logger.LogError(response.Exception, "Request failed with {StatusCode}. Waiting {TimeSpan} before next retry. Retry attempt {RetryCount}.", response.Result.StatusCode, timeSpan, retryCount); } }); }); } }