c# - 在 .NET Core Worker Service 中执行健康检查

Question

如何在 .NET Core Worker Service 中实现运行状况检查？

该服务将在 Docker 内部运行，并且需要能够检查服务的运行状况。

Answer 1

执行此操作的另一种方法是实现 IHealthCheckPublisher。

这种方法的好处是能够重用现有的 IHealthCheck 或与依赖 IHealthCheck 接口(interface)的第三方库集成(例如 this one ) .

虽然您仍然将 Microsoft.NET.Sdk.Web 作为 SDK，但您不需要添加任何 ASP.NET 细节。

这是一个例子:

public static IHostBuilder CreateHostBuilder(string[] args)
{
  return Host
    .CreateDefaultBuilder(args)
    .ConfigureServices((hostContext, services) =>
    {
      services
        .AddHealthChecks()
        .AddCheck<RedisHealthCheck>("redis_health_check")
        .AddCheck<RfaHealthCheck>("rfa_health_check");

      services.AddSingleton<IHealthCheckPublisher, HealthCheckPublisher>();
      services.Configure<HealthCheckPublisherOptions>(options =>
      {
        options.Delay = TimeSpan.FromSeconds(5);
        options.Period = TimeSpan.FromSeconds(5);
      });
    });
}

public class HealthCheckPublisher : IHealthCheckPublisher
{
  private readonly string _fileName;
  private HealthStatus _prevStatus = HealthStatus.Unhealthy;

  public HealthCheckPublisher()
  {
    _fileName = Environment.GetEnvironmentVariable(EnvVariableNames.DOCKER_HEALTHCHECK_FILEPATH) ??
                Path.GetTempFileName();
  }

  public Task PublishAsync(HealthReport report, CancellationToken cancellationToken)
  {
    // AWS will check if the file exists inside of the container with the command
    // test -f $DOCKER_HEALTH_CHECK_FILEPATH

    var fileExists = _prevStatus == HealthStatus.Healthy;

    if (report.Status == HealthStatus.Healthy)
    {
      if (!fileExists)
      {
        using var _ = File.Create(_fileName);
      }
    }
    else if (fileExists)
    {
      File.Delete(_fileName);
    }

    _prevStatus = report.Status;

    return Task.CompletedTask;
  }
}