Move the logic for reconciling the host targets of external load balancers

from the node controller to the service controller before impending changes
to the node controller make it not fit there anymore.

pkg/cloudprovider/servicecontroller/servicecontroller_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package servicecontroller
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
@@ -27,6 +28,10 @@ import (
 
 const region = "us-central"
 
+func newService(name string, uid types.UID, external bool) *api.Service {
+	return &api.Service{ObjectMeta: api.ObjectMeta{Name: name, Namespace: "namespace", UID: uid}, Spec: api.ServiceSpec{CreateExternalLoadBalancer: external}}
+}
+
 func TestCreateExternalLoadBalancer(t *testing.T) {
 	table := []struct {
 		service             *api.Service
@@ -124,4 +129,82 @@ func TestCreateExternalLoadBalancer(t *testing.T) {
 	}
 }
 
+// TODO: Finish converting and update comments
+func TestUpdateNodesInExternalLoadBalancer(t *testing.T) {
+	hosts := []string{"node0", "node1", "node73"}
+	table := []struct {
+		services            []*api.Service
+		expectedUpdateCalls []fake_cloud.FakeUpdateBalancerCall
+	}{
+		{
+			// No services present: no calls should be made.
+			services:            []*api.Service{},
+			expectedUpdateCalls: nil,
+		},
+		{
+			// Services do not have external load balancers: no calls should be made.
+			services: []*api.Service{
+				newService("s0", "111", false),
+				newService("s1", "222", false),
+			},
+			expectedUpdateCalls: nil,
+		},
+		{
+			// Services does have an external load balancer: one call should be made.
+			services: []*api.Service{
+				newService("s0", "333", true),
+			},
+			expectedUpdateCalls: []fake_cloud.FakeUpdateBalancerCall{
+				{Name: "a333", Region: region, Hosts: []string{"node0", "node1", "node73"}},
+			},
+		},
+		{
+			// Three services have an external load balancer: three calls.
+			services: []*api.Service{
+				newService("s0", "444", true),
+				newService("s1", "555", true),
+				newService("s2", "666", true),
+			},
+			expectedUpdateCalls: []fake_cloud.FakeUpdateBalancerCall{
+				{Name: "a444", Region: region, Hosts: []string{"node0", "node1", "node73"}},
+				{Name: "a555", Region: region, Hosts: []string{"node0", "node1", "node73"}},
+				{Name: "a666", Region: region, Hosts: []string{"node0", "node1", "node73"}},
+			},
+		},
+		{
+			// Two services have an external load balancer and two don't: two calls.
+			services: []*api.Service{
+				newService("s0", "777", false),
+				newService("s1", "888", true),
+				newService("s3", "999", true),
+				newService("s4", "123", false),
+			},
+			expectedUpdateCalls: []fake_cloud.FakeUpdateBalancerCall{
+				{Name: "a888", Region: region, Hosts: []string{"node0", "node1", "node73"}},
+				{Name: "a999", Region: region, Hosts: []string{"node0", "node1", "node73"}},
+			},
+		},
+	}
+	for _, item := range table {
+		cloud := &fake_cloud.FakeCloud{}
+
+		cloud.Region = region
+		client := &testclient.Fake{}
+		controller := New(cloud, client, "test-cluster2")
+		controller.init()
+		cloud.Calls = nil // ignore any cloud calls made in init()
+
+		var services []*cachedService
+		for _, service := range item.services {
+			services = append(services, &cachedService{service: service})
+		}
+		if err := controller.updateLoadBalancerHosts(services, hosts); err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if !reflect.DeepEqual(item.expectedUpdateCalls, cloud.UpdateCalls) {
+			t.Errorf("expected update calls mismatch, expected %+v, got %+v", item.expectedUpdateCalls, cloud.UpdateCalls)
+		}
+	}
+}
+
 // TODO(a-robinson): Add tests for update/sync/delete.