Implement multi-port endpoints

Instead of endpoints being a flat list, it is now a list of "subsets"
where each is a struct of {Addresses, Ports}.  To generate the list of
endpoints you need to take union of the Cartesian products of the
subsets.  This is compact in the vast majority of cases, yet still
represents named ports and corner cases (e.g. each pod has a different
port number).

This also stores subsets in a deterministic order (sorted by hash) to
avoid spurious updates and comparison problems.

This is a fully compatible change - old objects and clients will
keepworking as long as they don't need the new functionality.

This is the prep for multi-port Services, which will add API to produce
endpoints in this new structure.

pkg/registry/endpoint/etcd/etcd_test.go

@@ -50,15 +50,20 @@ func validNewEndpoints() *api.Endpoints {
 			Name:      "foo",
 			Namespace: api.NamespaceDefault,
 		},
-		Protocol:  "TCP",
-		Endpoints: []api.Endpoint{{IP: "baz"}},
+		Subsets: []api.EndpointSubset{{
+			Addresses: []api.EndpointAddress{{IP: "1.2.3.4"}},
+			Ports:     []api.EndpointPort{{Port: 80, Protocol: "TCP"}},
+		}},
 	}
 }
 
 func validChangedEndpoints() *api.Endpoints {
 	endpoints := validNewEndpoints()
 	endpoints.ResourceVersion = "1"
-	endpoints.Endpoints = []api.Endpoint{{IP: "baz"}, {IP: "bar"}}
+	endpoints.Subsets = []api.EndpointSubset{{
+		Addresses: []api.EndpointAddress{{IP: "1.2.3.4"}, {IP: "5.6.7.8"}},
+		Ports:     []api.EndpointPort{{Port: 80, Protocol: "TCP"}},
+	}}
 	return endpoints
 }
 
@@ -113,10 +118,18 @@ func TestEtcdListEndpoints(t *testing.T) {
 			Node: &etcd.Node{
 				Nodes: []*etcd.Node{
 					{
-						Value: runtime.EncodeOrDie(latest.Codec, &api.Endpoints{ObjectMeta: api.ObjectMeta{Name: "foo"}, Protocol: "TCP", Endpoints: []api.Endpoint{{IP: "127.0.0.1", Port: 8345}}}),
+						Value: runtime.EncodeOrDie(latest.Codec, &api.Endpoints{
+							ObjectMeta: api.ObjectMeta{Name: "foo"},
+							Subsets: []api.EndpointSubset{{
+								Addresses: []api.EndpointAddress{{IP: "127.0.0.1"}},
+								Ports:     []api.EndpointPort{{Port: 8345, Protocol: "TCP"}},
+							}},
+						}),
 					},
 					{
-						Value: runtime.EncodeOrDie(latest.Codec, &api.Endpoints{ObjectMeta: api.ObjectMeta{Name: "bar"}, Protocol: "TCP"}),
+						Value: runtime.EncodeOrDie(latest.Codec, &api.Endpoints{
+							ObjectMeta: api.ObjectMeta{Name: "bar"},
+						}),
 					},
 				},
 			},

pkg/registry/endpoint/rest.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	endptspkg "github.com/GoogleCloudPlatform/kubernetes/pkg/api/endpoints"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/validation"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
@@ -45,13 +46,15 @@ func (endpointsStrategy) NamespaceScoped() bool {
 
 // PrepareForCreate clears fields that are not allowed to be set by end users on creation.
 func (endpointsStrategy) PrepareForCreate(obj runtime.Object) {
-	_ = obj.(*api.Endpoints)
+	endpoints := obj.(*api.Endpoints)
+	endpoints.Subsets = endptspkg.RepackSubsets(endpoints.Subsets)
 }
 
 // PrepareForUpdate clears fields that are not allowed to be set by end users on update.
 func (endpointsStrategy) PrepareForUpdate(obj, old runtime.Object) {
-	_ = obj.(*api.Endpoints)
+	newEndpoints := obj.(*api.Endpoints)
 	_ = old.(*api.Endpoints)
+	newEndpoints.Subsets = endptspkg.RepackSubsets(newEndpoints.Subsets)
 }
 
 // Validate validates a new endpoints.

pkg/registry/etcd/etcd_test.go

@@ -539,7 +539,7 @@ func TestEtcdDeleteService(t *testing.T) {
 	key, _ := makeServiceKey(ctx, "foo")
 	fakeClient.Set(key, runtime.EncodeOrDie(latest.Codec, &api.Service{ObjectMeta: api.ObjectMeta{Name: "foo"}}), 0)
 	endpointsKey, _ := etcdgeneric.NamespaceKeyFunc(ctx, "/registry/services/endpoints", "foo")
-	fakeClient.Set(endpointsKey, runtime.EncodeOrDie(latest.Codec, &api.Endpoints{ObjectMeta: api.ObjectMeta{Name: "foo"}, Protocol: "TCP"}), 0)
+	fakeClient.Set(endpointsKey, runtime.EncodeOrDie(latest.Codec, &api.Endpoints{ObjectMeta: api.ObjectMeta{Name: "foo"}}), 0)
 
 	err := registry.DeleteService(ctx, "foo")
 	if err != nil {

pkg/registry/service/rest.go

@@ -23,6 +23,7 @@ import (
 	"net/http"
 	"net/url"
 	"strconv"
+	"strings"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
@@ -233,19 +234,43 @@ var _ = rest.Redirector(&REST{})
 
 // ResourceLocation returns a URL to which one can send traffic for the specified service.
 func (rs *REST) ResourceLocation(ctx api.Context, id string) (*url.URL, http.RoundTripper, error) {
-	eps, err := rs.endpoints.GetEndpoints(ctx, id)
+	// Allow ID as "svcname" or "svcname:port".
+	parts := strings.Split(id, ":")
+	if len(parts) > 2 {
+		return nil, nil, errors.NewBadRequest(fmt.Sprintf("invalid service request %q", id))
+	}
+	svcName := parts[0]
+	portStr := ""
+	if len(parts) == 2 {
+		portStr = parts[1]
+	}
+
+	eps, err := rs.endpoints.GetEndpoints(ctx, svcName)
 	if err != nil {
 		return nil, nil, err
 	}
-	if len(eps.Endpoints) == 0 {
-		return nil, nil, fmt.Errorf("no endpoints available for %v", id)
+	if len(eps.Subsets) == 0 {
+		return nil, nil, fmt.Errorf("no endpoints available for %q", svcName)
 	}
-	// We leave off the scheme ('http://') because we have no idea what sort of server
-	// is listening at this endpoint.
-	ep := &eps.Endpoints[rand.Intn(len(eps.Endpoints))]
-	return &url.URL{
-		Host: net.JoinHostPort(ep.IP, strconv.Itoa(ep.Port)),
-	}, nil, nil
+	// Pick a random Subset to start searching from.
+	ssSeed := rand.Intn(len(eps.Subsets))
+	// Find a Subset that has the port.
+	for ssi := 0; ssi < len(eps.Subsets); ssi++ {
+		ss := &eps.Subsets[(ssSeed+ssi)%len(eps.Subsets)]
+		for i := range ss.Ports {
+			if ss.Ports[i].Name == portStr {
+				// Pick a random address.
+				ip := ss.Addresses[rand.Intn(len(ss.Addresses))].IP
+				port := ss.Ports[i].Port
+				// We leave off the scheme ('http://') because we have no idea what sort of server
+				// is listening at this endpoint.
+				return &url.URL{
+					Host: net.JoinHostPort(ip, strconv.Itoa(port)),
+				}, nil, nil
+			}
+		}
+	}
+	return nil, nil, fmt.Errorf("no endpoints available for %q", id)
 }
 
 func (rs *REST) getLoadbalancerName(ctx api.Context, service *api.Service) string {

pkg/registry/service/rest_test.go

@@ -373,13 +373,10 @@ func TestServiceRegistryResourceLocation(t *testing.T) {
 					Name:      "foo",
 					Namespace: api.NamespaceDefault,
 				},
-				Endpoints: []api.Endpoint{
-					{
-						IP:   "100.100.100.100",
-						Port: 80,
-					},
-				},
-				Protocol: api.ProtocolTCP,
+				Subsets: []api.EndpointSubset{{
+					Addresses: []api.EndpointAddress{{IP: "1.2.3.4"}},
+					Ports:     []api.EndpointPort{{Name: "", Port: 80}, {Name: "p", Port: 93}},
+				}},
 			},
 		},
 	}
@@ -391,6 +388,8 @@ func TestServiceRegistryResourceLocation(t *testing.T) {
 		},
 	})
 	redirector := rest.Redirector(storage)
+
+	// Test a simple id.
 	location, _, err := redirector.ResourceLocation(ctx, "foo")
 	if err != nil {
 		t.Errorf("Unexpected error: %v", err)
@@ -398,10 +397,28 @@ func TestServiceRegistryResourceLocation(t *testing.T) {
 	if location == nil {
 		t.Errorf("Unexpected nil: %v", location)
 	}
-	if e, a := "//100.100.100.100:80", location.String(); e != a {
+	if e, a := "//1.2.3.4:80", location.String(); e != a {
 		t.Errorf("Expected %v, but got %v", e, a)
 	}
 
+	// Test a name + port.
+	location, _, err = redirector.ResourceLocation(ctx, "foo:p")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if location == nil {
+		t.Errorf("Unexpected nil: %v", location)
+	}
+	if e, a := "//1.2.3.4:93", location.String(); e != a {
+		t.Errorf("Expected %v, but got %v", e, a)
+	}
+
+	// Test a non-existent name + port.
+	location, _, err = redirector.ResourceLocation(ctx, "foo:q")
+	if err == nil {
+		t.Errorf("Unexpected nil error")
+	}
+
 	// Test error path
 	if _, _, err = redirector.ResourceLocation(ctx, "bar"); err == nil {
 		t.Errorf("unexpected nil error")