Deprecate client/selector (#1767)

* client/{grpc,rpc}: depricate selector (wip)

* {client,cmd}: remove client/selector

* deprecate client/selector

* router/static: fix lookup

* config/cmd: add support for legacy static selector flag

* config/cmd: add support for legacy dns selector flag

util/http/roundtripper.go

@@ -4,34 +4,35 @@ import (
 	"errors"
 	"net/http"
 
-	"github.com/micro/go-micro/v2/client/selector"
+	"github.com/micro/go-micro/v2/router"
+	"github.com/micro/go-micro/v2/selector"
 )
 
 type roundTripper struct {
 	rt   http.RoundTripper
-	st   selector.Strategy
+	st   selector.Selector
 	opts Options
 }
 
 func (r *roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	s, err := r.opts.Registry.GetService(req.URL.Host)
+	routes, err := r.opts.Router.Lookup(router.QueryService(req.URL.Host))
 	if err != nil {
 		return nil, err
 	}
 
-	next := r.st(s)
-
 	// rudimentary retry 3 times
 	for i := 0; i < 3; i++ {
-		n, err := next()
+		route, err := r.st.Select(routes)
 		if err != nil {
 			continue
 		}
-		req.URL.Host = n.Address
+
+		req.URL.Host = route.Address
 		w, err := r.rt.RoundTrip(req)
 		if err != nil {
 			continue
 		}
+
 		return w, nil
 	}