public static IServiceCollection AddServiceDiscovery(this IServiceCollection services, IConfiguration serviceOptionsConfiguration)
{
services.AddOptions();
// setup options
services.Configure <ServiceDiscoveryOptions>(serviceOptionsConfiguration);
// register consul client
services.AddSingleton <IConsulClient>(p => new ConsulClient(cfg =>
{
var options = p.GetRequiredService <IOptions <ServiceDiscoveryOptions> >().Value;
var serviceConfiguration = ServiceDiscoveryEnvFactory.Get(options);
if (!string.IsNullOrEmpty(serviceConfiguration.Consul.HttpEndpoint))
{
// if not configured, the client will use the default value "127.0.0.1:8500"
cfg.Address = new Uri(serviceConfiguration.Consul.HttpEndpoint);
}
}));
// register dns lookup
services.AddSingleton <IDnsQuery>(p =>
{
var options = p.GetRequiredService <IOptions <ServiceDiscoveryOptions> >().Value;
var serviceConfiguration = ServiceDiscoveryEnvFactory.Get(options);
var client = new LookupClient(IPAddress.Parse("127.0.0.1"), 8600);
if (serviceConfiguration.Consul.DnsEndpoint != null)
{
client = new LookupClient(serviceConfiguration.Consul.DnsEndpoint.ToIPEndPoint());
}
client.EnableAuditTrail = false;
client.UseCache = true;
client.MinimumCacheTimeout = TimeSpan.FromSeconds(1);
return(client);
});
return(services);
}
public static IApplicationBuilder UseConsulRegisterService(this IApplicationBuilder app)
{
var appLife = app.ApplicationServices.GetRequiredService <IApplicationLifetime>() ?? throw new ArgumentException("Missing dependency", nameof(IApplicationLifetime));
var options = app.ApplicationServices.GetRequiredService <IOptions <ServiceDiscoveryOptions> >() ?? throw new ArgumentException("Missing dependency", nameof(IOptions <ServiceDiscoveryOptions>));
var serviceOptions = ServiceDiscoveryEnvFactory.Get(options.Value);
var consul = app.ApplicationServices.GetRequiredService <IConsulClient>() ?? throw new ArgumentException("Missing dependency", nameof(IConsulClient));
var loggerFactory = app.ApplicationServices.GetRequiredService <ILoggerFactory>();
var logger = loggerFactory.CreateLogger("ServiceDiscoveryBuilder");
if (string.IsNullOrEmpty(serviceOptions.ServiceName))
{
throw new ArgumentException("Service Name must be configured", nameof(serviceOptions.ServiceName));
}
IEnumerable <Uri> addresses = null;
if (serviceOptions.Endpoints != null && serviceOptions.Endpoints.Length > 0)
{
logger.LogInformation($"Using {serviceOptions.Endpoints.Length} configured endpoints for service registration.");
addresses = serviceOptions.Endpoints.Select(p => new Uri(p));
}
else
{
logger.LogInformation($"Trying to use server.Features to figure out the service endpoints for service registration.");
var features = app.Properties["server.Features"] as FeatureCollection;
addresses = features.Get <IServerAddressesFeature>()
.Addresses
.Select(p => new Uri(p)).ToArray();
}
logger.LogInformation($"Found {addresses.Count()} endpoints: {string.Join(",", addresses.Select(p => p.OriginalString))}.");
foreach (var address in addresses)
{
var serviceId = $"{serviceOptions.ServiceName}_{address.Host}:{address.Port}";
logger.LogInformation($"Registering service {serviceId} for address {address}.");
var serviceChecks = new List <AgentServiceCheck>();
if (!string.IsNullOrEmpty(serviceOptions.HealthCheckTemplate))
{
var healthCheckUri = new Uri(address, serviceOptions.HealthCheckTemplate).OriginalString;
serviceChecks.Add(new AgentServiceCheck()
{
Status = HealthStatus.Passing,
DeregisterCriticalServiceAfter = TimeSpan.FromMinutes(1),
Interval = TimeSpan.FromSeconds(5),
HTTP = healthCheckUri
});
logger.LogInformation($"Adding healthcheck for service {serviceId}, checking {healthCheckUri}.");
}
var registration = new AgentServiceRegistration()
{
Checks = serviceChecks.ToArray(),
Address = address.Host,
ID = serviceId,
Name = serviceOptions.ServiceName,
Port = address.Port
};
consul.Agent.ServiceRegister(registration).GetAwaiter().GetResult();
appLife.ApplicationStopping.Register(() =>
{
consul.Agent.ServiceDeregister(serviceId).GetAwaiter().GetResult();
});
}
return(app);
}
