) *builtExtAuthz {
	service := &extauthzhttp.HttpService{
		PathPrefix: config.PathPrefix,
		ServerUri: &core.HttpUri{
			// Timeout is required.
			Timeout: timeoutOrDefault(config.Timeout),
			// Uri is required but actually not used in the ext_authz filter.
			Uri: fmt.Sprintf("http://%s", hostname),
			HttpUpstreamType: &core.HttpUri_Cluster{
				Cluster: cluster,
			},
		},