/// <summary>
/// Initializes a new instance of the <see cref="TcpHealthListener"/> class.
/// </summary>
/// <param name="healthListener">The registered <see cref="TcpHealthListener"/> instance.</param>
/// <param name="options">The registered options to configure the <see cref="TcpHealthListener"/>.</param>
/// <param name="logger">The logger to write diagnostic trace messages during accepting or rejecting TCP connections.</param>
/// <exception cref="ArgumentNullException">Thrown when the <paramref name="healthListener"/>, <paramref name="options"/>, or <paramref name="logger"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">Thrown when the <paramref name="options"/> doesn't have a filled-out value.</exception>
public TcpHealthCheckPublisher(TcpHealthListener healthListener, TcpHealthListenerOptions options, ILogger <TcpHealthCheckPublisher> logger)
{
Guard.NotNull(healthListener, nameof(healthListener), "Requires a TCP health listener to accept or reject TCP connections");
Guard.NotNull(options, nameof(options), "Requires a set of registered options to determine if the TCP connections should be accepted or rejected based on the health report");
Guard.NotNull(logger, nameof(logger), "Requires a logger instance to write diagnostic trace messages when TCP connections are accepted or rejected");
_healthListener = healthListener;
_options = options;
_logger = logger;
}
/// <summary>
/// Adds TCP health probing
/// </summary>
/// <remarks>
/// In order for the TCP health probes to work, ASP.NET Core Health Checks must be configured. You can configure
/// it here or do it yourself as well.
/// </remarks>
/// <param name="services">The collection of services to use in the application</param>
/// <param name="tcpConfigurationKey">The configuration key that defines TCP health port on which the health report is exposed.</param>
/// <param name="configureHealthChecks">The capability to configure the required health checks to expose, if required</param>
/// <param name="configureTcpListenerOptions">The capability to configure additional options how the <see cref="TcpHealthListener"/> works, if required</param>
/// <param name="configureHealthCheckPublisherOptions">
/// The capability to configure additional options regarding how fast or slow changes in the health report should affect the TCP probe's availability,
/// when the <see cref="TcpHealthListenerOptions.RejectTcpConnectionWhenUnhealthy"/> is set to <c>true</c>.
/// </param>
/// <returns>Collection of services to use in the application</returns>
/// <exception cref="ArgumentNullException">Thrown when the <paramref name="services"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">Thrown when the <paramref name="tcpConfigurationKey"/> is blank.</exception>
public static IServiceCollection AddTcpHealthProbes(
this IServiceCollection services,
string tcpConfigurationKey,
Action <IHealthChecksBuilder> configureHealthChecks = null,
Action <TcpHealthListenerOptions> configureTcpListenerOptions = null,
Action <HealthCheckPublisherOptions> configureHealthCheckPublisherOptions = null)
{
Guard.NotNull(services, nameof(services), "Requires a set of services to add the TCP health probe to");
Guard.NotNullOrWhitespace(tcpConfigurationKey, nameof(tcpConfigurationKey), "Requires a non-blank configuration key to retrieve the TCP port");
IHealthChecksBuilder healthCheckBuilder = services.AddHealthChecks();
configureHealthChecks?.Invoke(healthCheckBuilder);
var listenerOptions = new TcpHealthListenerOptions {
TcpPortConfigurationKey = tcpConfigurationKey
};
configureTcpListenerOptions?.Invoke(listenerOptions);
services.AddSingleton(listenerOptions);
if (listenerOptions.RejectTcpConnectionWhenUnhealthy)
{
services.Configure <HealthCheckPublisherOptions>(options =>
{
configureHealthCheckPublisherOptions?.Invoke(options);
});
services.AddSingleton <IHealthCheckPublisher, TcpHealthCheckPublisher>();
}
services.AddSingleton <TcpHealthListener>();
services.AddHostedService(serviceProvider => serviceProvider.GetRequiredService <TcpHealthListener>());
return(services);
}
/// <summary>
/// Initializes a new instance of the <see cref="TcpHealthListener"/> class.
/// </summary>
/// <param name="healthListener">The registered <see cref="TcpHealthListener"/> instance.</param>
/// <param name="options">The registered options to configure the <see cref="TcpHealthListener"/>.</param>
/// <exception cref="ArgumentNullException">Thrown when the <paramref name="healthListener"/>, or <paramref name="options"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">Thrown when the <paramref name="options"/> doesn't have a filled-out value.</exception>
public TcpHealthCheckPublisher(TcpHealthListener healthListener, TcpHealthListenerOptions options)
: this(healthListener, options, NullLogger <TcpHealthCheckPublisher> .Instance)
{
}