add router selector and network defaults

client/selector/router/router.go

@@ -0,0 +1,153 @@
+// Package router is a network/router selector
+package router
+
+import (
+	"context"
+	"net"
+	"sort"
+	"strconv"
+	"sync"
+
+	"github.com/micro/go-micro/client/selector"
+	"github.com/micro/go-micro/network/router"
+	"github.com/micro/go-micro/registry"
+)
+
+type routerSelector struct {
+	opts selector.Options
+
+	// the router
+	r router.Router
+}
+
+type routerKey struct{}
+
+func (r *routerSelector) Init(opts ...selector.Option) error {
+	// no op
+	return nil
+}
+
+func (r *routerSelector) Options() selector.Options {
+	return r.opts
+}
+
+func (r *routerSelector) Select(service string, opts ...selector.SelectOption) (selector.Next, error) {
+	// lookup router for routes for the service
+	routes, err := r.r.Table().Lookup(router.NewQuery(
+		router.QueryDestination(service),
+	))
+
+	if err != nil {
+		return nil, err
+	}
+
+	// no routes return not found error
+	if len(routes) == 0 {
+		return nil, selector.ErrNotFound
+	}
+
+	// TODO: apply filters by pseudo constructing service
+
+	// sort the routes based on metric
+	sort.Slice(routes, func(i, j int) bool {
+		return routes[i].Metric < routes[j].Metric
+	})
+
+	// roundrobin assuming routes are in metric preference order
+	var i int
+	var mtx sync.Mutex
+
+	return func() (*registry.Node, error) {
+		// get index and increment counter with every call to next
+		mtx.Lock()
+		idx := i
+		i++
+		mtx.Unlock()
+
+		// get route based on idx
+		route := routes[idx%len(routes)]
+
+		// defaults to gateway and no port
+		address := route.Gateway
+		port := 0
+
+		// check if its host:port
+		host, pr, err := net.SplitHostPort(address)
+		if err == nil {
+			pp, _ := strconv.Atoi(pr)
+			// set port
+			port = pp
+			// set address
+			address = host
+		}
+
+		// return as a node
+		return &registry.Node{
+			// TODO: add id and metadata if we can
+			Address: address,
+			Port:    port,
+		}, nil
+	}, nil
+}
+
+func (r *routerSelector) Mark(service string, node *registry.Node, err error) {
+	// TODO: pass back metrics or information to the router
+	return
+}
+
+func (r *routerSelector) Reset(service string) {
+	// TODO: reset the metrics or information at the router
+	return
+}
+
+func (r *routerSelector) Close() error {
+	// stop the router advertisements
+	return r.r.Stop()
+}
+
+func (r *routerSelector) String() string {
+	return "router"
+}
+
+// NewSelector returns a new router based selector
+func NewSelector(opts ...selector.Option) selector.Selector {
+	options := selector.Options{
+		Context: context.Background(),
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	// set default registry if not set
+	if options.Registry == nil {
+		options.Registry = registry.DefaultRegistry
+	}
+
+	// try get from the context
+	r, ok := options.Context.Value(routerKey{}).(router.Router)
+	if !ok {
+		// TODO: Use router.DefaultRouter?
+		r = router.NewRouter(
+			router.Registry(options.Registry),
+		)
+	}
+
+	// start the router advertisements
+	r.Advertise()
+
+	return &routerSelector{
+		opts: options,
+		r:    r,
+	}
+}
+
+// WithRouter sets the router as an option
+func WithRouter(r router.Router) selector.Option {
+	return func(o *selector.Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, routerKey{}, r)
+	}
+}

config/cmd/cmd.go

@@ -34,6 +34,7 @@ import (
 	// selectors
 	"github.com/micro/go-micro/client/selector"
 	"github.com/micro/go-micro/client/selector/dns"
+	"github.com/micro/go-micro/client/selector/router"
 	"github.com/micro/go-micro/client/selector/static"
 
 	// transports
@@ -196,6 +197,7 @@ var (
 		"default": selector.NewSelector,
 		"dns":     dns.NewSelector,
 		"cache":   selector.NewSelector,
+		"router":  router.NewSelector,
 		"static":  static.NewSelector,
 	}
 

network/default.go

@@ -0,0 +1,95 @@
+package network
+
+import (
+	"sync"
+
+	"github.com/micro/go-micro/config/options"
+	"github.com/micro/go-micro/network/router"
+	"github.com/micro/go-micro/network/proxy"
+)
+
+type network struct {
+	options.Options
+
+	// router
+	r router.Router
+
+	// proxy
+	p proxy.Proxy
+
+	// id of this network
+	id string
+
+	// links maintained for this network
+	mtx sync.RWMutex
+	links []Link
+}
+
+type node struct {
+	*network
+
+	// address of this node
+	address string
+}
+
+
+type link struct {
+	// the embedded node
+	*node
+
+	// length and weight of the link
+	mtx sync.RWMutex
+	length, weight int
+}
+
+// network methods
+
+func (n *network) Id() string {
+	return n.id
+}
+
+func (n *network) Connect() (Node, error) {
+	return nil, nil
+}
+
+func (n *network) Peer(Network) (Link, error) {
+	return nil, nil
+}
+
+func (n *network) Links() ([]Link, error) {
+	n.mtx.RLock()
+	defer n.mtx.RUnlock()
+	return n.links, nil
+}
+
+// node methods
+
+func (n *node) Address() string {
+	return n.address
+}
+
+func (n *node) Close() error {
+	return nil
+}
+
+func (n *node) Accept() (*Message, error) {
+	return nil, nil
+}
+
+func (n *node) Send(*Message) error {
+	return nil
+}
+
+// link methods
+
+func (l *link) Length() int {
+	l.mtx.RLock()
+	defer l.mtx.RUnlock()
+	return l.length
+}
+
+func (l *link) Weight() int {
+	l.mtx.RLock()
+	defer l.mtx.RUnlock()
+	return l.weight
+}

network/network.go

@@ -51,6 +51,25 @@ type Message struct {
 }
 
 var (
-	// TODO: set default network
-	DefaultNetwork Network
+	// The default network ID is local
+	DefaultNetworkId = "local"
+
+	// just the standard network element
+	DefaultNetwork = NewNetwork()
 )
+
+// NewNetwork returns a new network
+func NewNetwork(opts ...options.Option) Network {
+	options := options.NewOptions(opts...)
+
+	// get router
+
+	// get proxy
+
+	return &network{
+		Options: options,
+		// fill the blanks
+		// router: r,
+		// proxy: p,
+	}
+}

network/proxy/mucp/mucp.go

@@ -7,10 +7,12 @@ import (
 	"strings"
 
 	"github.com/micro/go-micro/client"
+	rselect "github.com/micro/go-micro/client/selector/router"
 	"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"
 )
 
@@ -162,5 +164,18 @@ func NewProxy(opts ...options.Option) proxy.Proxy {
 		p.Client = c.(client.Client)
 	}
 
+	// 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)),
+			)),
+		)
+	}
+
 	return p
 }

network/proxy/proxy.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/micro/go-micro/client"
 	"github.com/micro/go-micro/config/options"
+	"github.com/micro/go-micro/network/router"
 	"github.com/micro/go-micro/server"
 )
 
@@ -29,3 +30,8 @@ func WithEndpoint(e string) options.Option {
 func WithClient(c client.Client) options.Option {
 	return options.WithValue("proxy.client", c)
 }
+
+// WithRouter specifies the router to use
+func WithRouter(r router.Router) options.Option {
+	return options.WithValue("proxy.router", r)
+}