func NewDiscovery(conf *SDConfig, logger log.Logger) (*Discovery, error) {
	if logger == nil {
		logger = log.NewNopLogger()
	}

	tls, err := config_util.NewTLSConfig(&conf.TLSConfig)
	if err != nil {
		return nil, err
	}
	transport := &http.Transport{
		IdleConnTimeout: 5 * time.Duration(conf.RefreshInterval),
		TLSClientConfig: tls,
		DialContext: conntrack.NewDialContextFunc(
			conntrack.DialWithTracing(),
			conntrack.DialWithName("consul_sd"),
		),
	}
	wrapper := &http.Client{
		Transport: transport,
		Timeout:   35 * time.Second,
	}

	clientConf := &consul.Config{
		Address:    conf.Server,
		Scheme:     conf.Scheme,
		Datacenter: conf.Datacenter,
		Token:      string(conf.Token),
		HttpAuth: &consul.HttpBasicAuth{
			Username: conf.Username,
			Password: string(conf.Password),
		},
		HttpClient: wrapper,
	}
	client, err := consul.NewClient(clientConf)
	if err != nil {
		return nil, err
	}
	cd := &Discovery{
		client:           client,
		tagSeparator:     conf.TagSeparator,
		watchedServices:  conf.Services,
		watchedTags:      conf.ServiceTags,
		watchedNodeMeta:  conf.NodeMeta,
		allowStale:       conf.AllowStale,
		refreshInterval:  time.Duration(conf.RefreshInterval),
		clientDatacenter: conf.Datacenter,
		finalizer:        transport.CloseIdleConnections,
		logger:           logger,
	}
	return cd, nil
}
func NewDiscovery(conf *SDConfig, logger log.Logger) (*Discovery, error) {
	if logger == nil {
		logger = log.NewNopLogger()
	}

	tls, err := config_util.NewTLSConfig(&conf.TLSConfig)
	if err != nil {
		return nil, err
	}
	transport := &http.Transport{
		IdleConnTimeout: 5 * time.Duration(conf.RefreshInterval),
		TLSClientConfig: tls,
		DialContext: conntrack.NewDialContextFunc(
			conntrack.DialWithTracing(),
			conntrack.DialWithName("consul_sd"),
		),
	}
	wrapper := &http.Client{
		Transport: transport,
		Timeout:   35 * time.Second,
	}

	clientConf := &consul.Config{
		Address:    conf.Server,
		Scheme:     conf.Scheme,
		Datacenter: conf.Datacenter,
		Token:      string(conf.Token),
		HttpAuth: &consul.HttpBasicAuth{
			Username: conf.Username,
			Password: string(conf.Password),
		},
		HttpClient: wrapper,
	}
	client, err := consul.NewClient(clientConf)
	if err != nil {
		return nil, err
	}
	cd := &Discovery{
		client:           client,
		tagSeparator:     conf.TagSeparator,
		watchedServices:  conf.Services,
		watchedTags:      conf.ServiceTags,
		watchedNodeMeta:  conf.NodeMeta,
		allowStale:       conf.AllowStale,
		refreshInterval:  time.Duration(conf.RefreshInterval),
		clientDatacenter: conf.Datacenter,
		finalizer:        transport.CloseIdleConnections,
		logger:           logger,
	}
	return cd, nil
}
// NewDiscovery returns a new Discovery for the given config.