Files
Swarm/DysonNetwork.Shared/Registry/ServiceRegistrar.cs

93 lines
2.8 KiB
C#

using dotnet_etcd;
using Etcdserverpb;
using Google.Protobuf;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
namespace DysonNetwork.Shared.Registry;
public class ServiceRegistrar(EtcdClient etcd)
{
private CancellationTokenSource? _cts;
private string? _serviceKey;
private long _leaseId;
private long _ttlSeconds;
/// <summary>
/// Register the service in etcd with a TTL lease.
/// </summary>
public async Task RegisterAsync(string serviceName, string servicePart, string instanceId, string host, int port, long ttlSeconds = 30)
{
_ttlSeconds = ttlSeconds;
_serviceKey = $"/services/{serviceName}/${servicePart}/{instanceId}";
var serviceValue = $"{host}:{port}";
// Create and store TTL lease
var leaseResp = await etcd.LeaseGrantAsync(new LeaseGrantRequest { TTL = _ttlSeconds });
_leaseId = leaseResp.ID;
await etcd.PutAsync(new PutRequest()
{
Key = ByteString.CopyFromUtf8(_serviceKey),
Value = ByteString.CopyFromUtf8(serviceValue),
Lease = _leaseId
});
// Start a background task to keep the lease alive
_cts = new CancellationTokenSource();
_ = Task.Run(async () =>
{
while (!_cts.Token.IsCancellationRequested)
{
try
{
await etcd.LeaseKeepAlive(_leaseId, _cts.Token);
await Task.Delay(TimeSpan.FromSeconds(_ttlSeconds / 2), _cts.Token);
}
catch (Exception ex)
{
Console.WriteLine($"Error keeping lease alive: {ex.Message}");
break;
}
}
}, _cts.Token);
}
public async Task DeregisterAsync()
{
await _cts?.CancelAsync();
if (_serviceKey != null)
{
try
{
await etcd.DeleteAsync(_serviceKey);
}
catch
{
// ignore delete errors
}
}
}
}
public class ServiceRegistrarHostedService(ServiceRegistrar registrar, IConfiguration config) : IHostedService
{
public async Task StartAsync(CancellationToken cancellationToken)
{
var name = config["Service:Name"];
var host = config["Service:Host"];
var grpcPort = int.Parse(config["Service:GrpcPort"]!);
var httpPort = int.Parse(config["Service:HttpPort"]!);
var instanceId = config["Service:InstanceId"] ?? Guid.NewGuid().ToString("N");
await registrar.RegisterAsync(name, "grpc", instanceId, host, grpcPort);
await registrar.RegisterAsync(name, "http", instanceId, host, httpPort);
}
public async Task StopAsync(CancellationToken cancellationToken)
{
await registrar.DeregisterAsync();
}
}