Use the router to get routes

network/proxy/mucp/mucp.go

@@ -3,17 +3,22 @@ package mucp
 
 import (
 	"context"
+	"fmt"
 	"io"
+	"os"
 	"strings"
+	"sync"
 
 	"github.com/micro/go-micro/client"
-	rselect "github.com/micro/go-micro/client/selector/router"
+	"github.com/micro/go-micro/client/selector"
 	"github.com/micro/go-micro/codec"
 	"github.com/micro/go-micro/codec/bytes"
 	"github.com/micro/go-micro/config/options"
 	"github.com/micro/go-micro/network/proxy"
 	"github.com/micro/go-micro/network/router"
 	"github.com/micro/go-micro/server"
+
+	pb "github.com/micro/go-micro/network/router/proto"
 )
 
 // Proxy will transparently proxy requests to an endpoint.
@@ -27,6 +32,16 @@ type Proxy struct {
 
 	// The client to use for outbound requests
 	Client client.Client
+
+	// The router for routes
+	Router router.Router
+
+	// The router service client
+	RouterService pb.RouterService
+
+	// A fib of routes service:address
+	sync.RWMutex
+	Routes map[string][]router.Route
 }
 
 // read client request and write to server
@@ -64,6 +79,142 @@ func readLoop(r server.Request, s client.Stream) error {
 	}
 }
 
+func (p *Proxy) getRoute(service string) ([]string, error) {
+	// converts routes to just addresses
+	toNodes := func(routes []router.Route) []string {
+		var nodes []string
+		for _, node := range routes {
+			nodes = append(nodes, node.Gateway)
+		}
+		return nodes
+	}
+
+	// lookup the route cache first
+	p.RLock()
+	routes, ok := p.Routes[service]
+	// got it!
+	if ok {
+		p.RUnlock()
+		return toNodes(routes), nil
+	}
+	p.RUnlock()
+
+	// route cache miss, now lookup the router
+	// if it does not exist, don't error out
+	// the proxy will just hand off to the client
+	// and try the registry
+	// in future we might set a default gateway
+	if p.Router != nil {
+		// lookup the router
+		routes, err := p.Router.Table().Lookup(
+			router.NewQuery(router.QueryDestination(service)),
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		p.Lock()
+		if p.Routes == nil {
+			p.Routes = make(map[string][]router.Route)
+		}
+		p.Routes[service] = routes
+		p.Unlock()
+
+		return toNodes(routes), nil
+	}
+
+	// we've tried getting cached routes
+	// we've tried using the router
+	addr := os.Getenv("MICRO_ROUTER_ADDRESS")
+	name := os.Getenv("MICRO_ROUTER")
+
+	// no router is specified we're going to set the default
+	if len(name) == 0 && len(addr) == 0 {
+		p.Router = router.DefaultRouter
+		// recursively execute getRoute
+		return p.getRoute(service)
+	}
+
+	if len(name) == 0 {
+		name = "go.micro.router"
+	}
+
+	// lookup the remote router
+
+	var addrs []string
+
+	// set the remote address if specified
+	if len(addr) > 0 {
+		addrs = append(addrs, addr)
+	} else {
+		// we have a name so we need to check the registry
+		services, err := p.Client.Options().Registry.GetService(name)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, service := range services {
+			for _, node := range service.Nodes {
+				addr := node.Address
+				if node.Port > 0 {
+					addr = fmt.Sprintf("%s:%d", node.Address, node.Port)
+				}
+				addrs = append(addrs, addr)
+			}
+		}
+	}
+
+	// no router addresses available
+	if len(addrs) == 0 {
+		return nil, selector.ErrNoneAvailable
+	}
+
+	var pbRoutes *pb.LookupResponse
+	var err error
+
+	// set default client
+	if p.RouterService == nil {
+		p.RouterService = pb.NewRouterService(name, p.Client)
+	}
+
+	// TODO: implement backoff and retries
+	for _, addr := range addrs {
+		// call the router
+		pbRoutes, err = p.RouterService.Lookup(context.Background(), &pb.LookupRequest{
+			Query: &pb.Query{
+				Destination: service,
+			},
+		}, client.WithAddress(addr))
+		if err != nil {
+			continue
+		}
+		break
+	}
+
+	// errored out
+	if err != nil {
+		return nil, err
+	}
+
+	// no routes
+	if pbRoutes == nil {
+		return nil, selector.ErrNoneAvailable
+	}
+
+	// convert from pb to []*router.Route
+	for _, r := range pbRoutes.Routes {
+		routes = append(routes, router.Route{
+			Destination: r.Destination,
+			Gateway:     r.Gateway,
+			Router:      r.Router,
+			Network:     r.Network,
+			Metric:      int(r.Metric),
+		})
+	}
+
+	return toNodes(routes), nil
+}
+
 // ServeRequest honours the server.Router interface
 func (p *Proxy) ServeRequest(ctx context.Context, req server.Request, rsp server.Response) error {
 	// set default client
@@ -71,21 +222,42 @@ func (p *Proxy) ServeRequest(ctx context.Context, req server.Request, rsp server
 		p.Client = client.DefaultClient
 	}
 
-	opts := []client.CallOption{}
-
 	// service name
 	service := req.Service()
 	endpoint := req.Endpoint()
+	var addresses []string
 
-	// call a specific backend
+	// call a specific backend endpoint either by name or address
 	if len(p.Endpoint) > 0 {
 		// address:port
 		if parts := strings.Split(p.Endpoint, ":"); len(parts) > 1 {
-			opts = append(opts, client.WithAddress(p.Endpoint))
-			// use as service name
+			addresses = []string{p.Endpoint}
 		} else {
+			// get route for endpoint from router
+			addr, err := p.getRoute(p.Endpoint)
+			if err != nil {
+				return err
+			}
+			// set the address
+			addresses = addr
+			// set the name
 			service = p.Endpoint
 		}
+	} else {
+		// no endpoint was specified just lookup the route
+		// get route for endpoint from router
+		addr, err := p.getRoute(service)
+		if err != nil {
+			return err
+		}
+		addresses = addr
+	}
+
+	var opts []client.CallOption
+
+	// set address if available
+	if len(addresses) > 0 {
+		opts = append(opts, client.WithAddress(addresses...))
 	}
 
 	// read initial request
@@ -167,14 +339,7 @@ func NewProxy(opts ...options.Option) proxy.Proxy {
 	// get router
 	r, ok := p.Options.Values().Get("proxy.router")
 	if ok {
-		// set the router in the client
-		p.Client.Init(
-			// pass new selector as an option to the client
-			client.Selector(rselect.NewSelector(
-				// set the router in the selector
-				rselect.WithRouter(r.(router.Router)),
-			)),
-		)
+		p.Router = r.(router.Router)
 	}
 
 	return p