router: add to service options; add dns and static implementations (#1733)

* config/cmd: add router to service options

* router/service: use micro client

static.go

@@ -0,0 +1,88 @@
+package static
+
+import "github.com/micro/go-micro/v2/router"
+
+// NewRouter returns an initialized static router
+func NewRouter(opts ...router.Option) router.Router {
+	options := router.DefaultOptions()
+	for _, o := range opts {
+		o(&options)
+	}
+	return &static{options, new(table)}
+}
+
+type static struct {
+	options router.Options
+	table   router.Table
+}
+
+func (s *static) Init(opts ...router.Option) error {
+	for _, o := range opts {
+		o(&s.options)
+	}
+	return nil
+}
+
+func (s *static) Options() router.Options {
+	return s.options
+}
+
+func (s *static) Table() router.Table {
+	return nil
+}
+
+func (s *static) Advertise() (<-chan *router.Advert, error) {
+	return nil, nil
+}
+
+func (s *static) Process(*router.Advert) error {
+	return nil
+}
+
+func (s *static) Lookup(...router.QueryOption) ([]router.Route, error) {
+	return nil, nil
+}
+
+func (s *static) Watch(opts ...router.WatchOption) (router.Watcher, error) {
+	return nil, nil
+}
+
+func (s *static) Close() error {
+	return nil
+}
+
+func (s *static) String() string {
+	return "static"
+}
+
+type table struct{}
+
+func (t *table) Create(router.Route) error {
+	return nil
+}
+
+func (t *table) Delete(router.Route) error {
+	return nil
+}
+
+func (t *table) Update(router.Route) error {
+	return nil
+}
+
+func (t *table) List() ([]router.Route, error) {
+	return nil, nil
+}
+
+func (t *table) Query(opts ...router.QueryOption) ([]router.Route, error) {
+	options := router.NewQuery(opts...)
+
+	return []router.Route{
+		router.Route{
+			Address: options.Service,
+			Service: options.Address,
+			Gateway: options.Gateway,
+			Network: options.Network,
+			Router:  options.Router,
+		},
+	}, nil
+}