Config seed provider

ConfigSeedProvider returns a static list of seed addresses — from a constructor argument or environment variables. No discovery logic; what you configure is what you get.

import { Cluster, ConfigSeedProvider } from 'actor-ts';

const provider = new ConfigSeedProvider({
  seeds: ['10.0.0.5:2552', '10.0.0.6:2552', '10.0.0.7:2552'],
});

const seeds = await provider.lookup();
await Cluster.join(system, { host, port, seeds });

The simplest provider for the simplest case.

Configuration

interface ConfigSeedProviderSettings {
  seeds?:     string[];           // explicit list
  envVar?:    string;             // env-var name (CSV)
}

Two ways to specify:

// Explicit:
new ConfigSeedProvider({ seeds: ['10.0.0.5:2552', '10.0.0.6:2552'] });

// From env (CSV):
new ConfigSeedProvider({ envVar: 'ACTOR_TS_SEEDS' });
// where ACTOR_TS_SEEDS='10.0.0.5:2552,10.0.0.6:2552'

Pick whichever fits your deployment pattern. Env vars are typical for containerized deployments where the list comes from a config map / orchestrator.

When to use it

Three good fits:

1. Docker Compose — known service names + ports; actor-ts-1:2552,actor-ts-2:2552,actor-ts-3:2552 in env.
2. VMs with fixed IPs — three production VMs, each with a stable address.
3. Tests — known peer addresses inline in test setup.

When NOT

Dynamic environments

// K8s pods have ephemeral IPs:
new ConfigSeedProvider({ seeds: ['10.244.1.5:2552'] });   // ✗ breaks on pod recreation

Pod IPs change on every recreation. Use KubernetesApiSeedProvider instead.

Auto-scaling

Fixed seed lists don’t grow when nodes scale up. Once the cluster exists, gossip handles new joiners — but for first contact, only the configured seeds are tried. Aggregate with a DNS or K8s provider for dynamism.

Hostnames vs IPs

new ConfigSeedProvider({ seeds: ['my-pod.svc.cluster.local:2552'] });

Hostnames are resolved at lookup time. If your DNS lags pod startup, lookup fails and Cluster.join retries. Usually works — but IPs are more deterministic when available.

Where to next

• Discovery overview — the bigger picture.
• DNS seed provider — for DNS-based discovery.
• Kubernetes API seed provider — for K8s deployments.
• Aggregate seed provider — combine multiple providers.
• Joining and seeds — how seeds are consumed by the cluster bootstrap.