Novolis.Transports.Discovery 2026.1.11.85

Novolis.Transports.Discovery

Cohort-aware service discovery for local and routed networks. The package provides:

• UDP probe and beacon helpers for zero-configuration LAN discovery.
• DNS SRV/TXT resolution for services published by managed DNS or Tailscale DNS.
• An HTTP(S) lease-registry client for routed networks and coordinated environments.
• A thread-safe ServiceDiscoveryMap that merges results from any source.

Install

<PackageReference Include="Novolis.Transports.Discovery" Version="2026.1.*" />

Quick start

Create a query and resolve the matching service registrations:

Every registration has a cohort, serviceName, and instanceId. A caller can merge multiple sources without making the product protocol part of this package:

using Novolis.Transports.Discovery;

var query = new ServiceDiscoveryQuery("reach", "host");
var map = new ServiceDiscoveryMap();

var dns = new DnsSrvServiceDiscovery(
    new DnsSrvServiceDiscoveryOptions("example.internal"));
var services = await dns.DiscoverAsync(query, cancellationToken);

map.Replace(services);
var hosts = map.Find(query);

ServiceDiscoveryMap is deliberately a snapshot map. Use RefreshAsync for a one-shot concurrent query of multiple sources, then refresh periodically, subscribe to a registry stream, or combine DNS with another source as needed.

DNS SRV/TXT

For the query above, the resolver asks for:

_host._tcp.reach.example.internal

Each SRV record becomes one service instance. TXT values at the same name use key=value syntax and become instance metadata:

_host._tcp.reach.example.internal. 60 IN SRV 0 0 19800 host-a.example.internal.
_host._tcp.reach.example.internal. 60 IN TXT "hostName=host-a" "protocolVersion=1.0"

DNS publishing is intentionally left to the network's DNS or service advertisement system. The resolver works with ordinary DNS servers and does not require a product-specific coordinator.

HTTP(S) lease registry

HttpServiceRegistry uses an intentionally small REST contract:

The PUT body contains the registration plus leaseDurationSeconds. The registry removes entries after the lease expires, so a stopped process does not remain in the cohort map indefinitely.

using var http = new HttpClient
{
    BaseAddress = new Uri("https://registry.example.internal/"),
};
var registry = new HttpServiceRegistry(
    http,
    http.BaseAddress);

var registration = new ServiceRegistration(
    "reach",
    "host",
    Environment.MachineName,
    new[] { new ServiceEndpoint(new Uri("tcp://10.0.0.25:19800")) },
    new Dictionary<string, string>
    {
        ["hostName"] = Environment.MachineName,
        ["protocolVersion"] = "1.0",
    });

var session = new ServiceRegistrationSession(
    registry,
    registration,
    leaseDuration: TimeSpan.FromSeconds(30),
    renewalPeriod: TimeSpan.FromSeconds(10));
await session.RunAsync(cancellationToken);

Configure authentication and certificate validation on the supplied HttpClient; the library does not embed credentials.

UDP compatibility

Use DiscoveryScanner for probes and DiscoveryResponder for generic beacon responses. These primitives remain available for products such as Reach that need zero-configuration broadcast discovery on a trusted LAN.