@grest-ts/discovery

Base package for service discovery in grest-ts. Provides the abstract class, types, and locator key that all discovery implementations build on.

For a full overview of how discovery works and available implementations, see the Discovery guide.

Exports

GGDiscoveryClient (abstract class)

The base class all discovery implementations extend:

abstract class GGDiscoveryClient {
    readonly isLocal: boolean = false;

    abstract registerRoutes(registrations: GGServiceRegistration[]): void;
    abstract register(): Promise<void>;
    abstract unregister(): Promise<void>;
    abstract discoverApi(apiName: string): Promise<string>;
}

Method	Purpose
registerRoutes()	Called when an HTTP server starts. Tells discovery what APIs this service provides.
register()	Registers the service with the discovery backend.
unregister()	Cleans up on shutdown.
discoverApi()	Returns the full URL for a given API name. This is what clients call.

The isLocal flag indicates local development mode. When true, cloud resources (AWS SNS, etc.) should use local adapters instead.

GG_DISCOVERY (locator key)

const GG_DISCOVERY = new GGLocatorKey<GGDiscoveryClient>("GGDiscovery");

Service locator key for registering and accessing the active discovery client.

GGServiceRegistration (interface)

interface GGServiceRegistration {
    runtime: string;       // Service name
    api: string;           // API name, e.g. "UserApi"
    protocol: "http" | "ws";
    port: number;
    pathPrefix: string;    // e.g. "/api/users/"
}

Implementations

Package	Use case
@grest-ts/discovery-static	Production deployments with known URLs
@grest-ts/discovery-local	Local development and testing
@grest-ts/discovery-kubernetes	Kubernetes deployments
@grest-ts/discovery-migration	Zero-downtime migration between strategies