discovery

type GCEDiscoverer struct {
	ProjectID string // GCP project ID
	Zone      string // GCE zone (e.g., "us-central1-a")
	SelfName  string // this instance's name (excluded from results)
	Tag       string // instance tag to filter by (e.g., "gluon-ion")

	// HTTPClient is an optional HTTP client for making API calls.
	// If nil, a default client is used. Useful for testing.
	HTTPClient *http.Client

	// TokenURL overrides the metadata server URL for fetching access tokens.
	// Defaults to the GCE metadata server. Useful for testing.
	TokenURL string

	// BaseURL overrides the Compute API base URL.
	// Defaults to https://compute.googleapis.com. Useful for testing.
	BaseURL string
}

type PeerDiscoverer interface {
	// Discover returns peer addresses (host:port or just host).
	Discover(ctx context.Context) ([]string, error)
	// Name returns a human-readable discoverer name for logging.
	Name() string
}

type StaticDiscoverer struct {
	Peers []string
}