xdsType := "GRPC"
	if features.DeltaXds {
		xdsType = "DELTA_GRPC"
	}

	// Waypoint overrides
	metadataDiscovery := cfg.Metadata.MetadataDiscovery
	if strings.HasPrefix(cfg.ID, "waypoint~") {
		xdsType = "DELTA_GRPC"
		metadataDiscovery = true
	}

	opts = append(opts,
		option.NodeID(cfg.ID),
		option.NodeType(cfg.ID),

		ProxyNamespace:              PodNamespaceVar.Get(),
		ProxyDomain:                 proxy.DNSDomain,
		IstiodSAN:                   istiodSAN.Get(),
		UseExternalWorkloadSDS:      useExternalWorkloadSDSEnv,
		MetadataDiscovery:           enableWDSEnv,
		SDSFactory:                  sds,
	}
	extractXDSHeadersFromEnv(o)
	return o
}

// Simplified extraction of gRPC headers from environment.

}

func STSEnabled(value bool) Instance {
	return newOption("sts", value)
}

func DiscoveryHost(value string) Instance {
	return newOption("discovery_host", value)
}

func MetadataDiscovery(value bool) Instance {
	return newOption("metadata_discovery", value)
}

func MetricsLocalhostAccessOnly(proxyMetadata map[string]string) Instance {
	value, ok := proxyMetadata["METRICS_LOCALHOST_ACCESS_ONLY"]

		EnvoyStatusPort:             a.cfg.EnvoyStatusPort,
		ExitOnZeroActiveConnections: a.cfg.ExitOnZeroActiveConnections,
		XDSRootCert:                 a.cfg.XDSRootCerts,
		MetadataDiscovery:           a.cfg.MetadataDiscovery,
	})
}

func (a *Agent) initializeEnvoyAgent(_ context.Context) error {
	node, err := a.generateNodeMetadata()
	if err != nil {

	// The istiod address when running ASM Managed Control Plane.
	CloudrunAddr string `json:"CLOUDRUN_ADDR,omitempty"`

	// Metadata discovery service enablement
	MetadataDiscovery StringBool `json:"METADATA_DISCOVERY,omitempty"`

	// Contains a copy of the raw metadata. This is needed to lookup arbitrary values.