Change CreateTCPLoadBalancer -> EnsureTCPLoadBalancer; implementations auto-delete if already exists

Previously the servicecontroller would do the delete, but by having the cloudprovider
take that task on, we can later remove it from the servicecontroller, and the
cloudprovider can do something more efficient.

pkg/cloudprovider/cloud.go

@@ -80,8 +80,8 @@ type TCPLoadBalancer interface {
 	// GetTCPLoadBalancer returns whether the specified load balancer exists, and
 	// if so, what its status is.
 	GetTCPLoadBalancer(name, region string) (status *api.LoadBalancerStatus, exists bool, err error)
-	// CreateTCPLoadBalancer creates a new tcp load balancer. Returns the status of the balancer
-	CreateTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinityType api.ServiceAffinity) (*api.LoadBalancerStatus, error)
+	// EnsureTCPLoadBalancer creates a new tcp load balancer, or updates an existing one. Returns the status of the balancer
+	EnsureTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinityType api.ServiceAffinity) (*api.LoadBalancerStatus, error)
 	// UpdateTCPLoadBalancer updates hosts under the specified load balancer.
 	UpdateTCPLoadBalancer(name, region string, hosts []string) error
 	// EnsureTCPLoadBalancerDeleted deletes the specified load balancer if it

pkg/cloudprovider/providers/aws/aws.go

@@ -1584,8 +1584,23 @@ func (s *AWSCloud) createTags(request *ec2.CreateTagsInput) (*ec2.CreateTagsOutp
 // CreateTCPLoadBalancer implements TCPLoadBalancer.CreateTCPLoadBalancer
 // TODO(justinsb): This must be idempotent
 // TODO(justinsb) It is weird that these take a region.  I suspect it won't work cross-region anwyay.
-func (s *AWSCloud) CreateTCPLoadBalancer(name, region string, publicIP net.IP, ports []*api.ServicePort, hosts []string, affinity api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
-	glog.V(2).Infof("CreateTCPLoadBalancer(%v, %v, %v, %v, %v)", name, region, publicIP, ports, hosts)
+func (s *AWSCloud) EnsureTCPLoadBalancer(name, region string, publicIP net.IP, ports []*api.ServicePort, hosts []string, affinity api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
+	glog.V(2).Infof("EnsureTCPLoadBalancer(%v, %v, %v, %v, %v)", name, region, publicIP, ports, hosts)
+
+	glog.V(2).Info("Checking if load balancer already exists: %s", name)
+	_, exists, err := s.GetTCPLoadBalancer(name, region)
+	if err != nil {
+		return nil, fmt.Errorf("error checking if AWS load balancer already exists: %v", err)
+	}
+
+	// TODO: Implement a more efficient update strategy for common changes than delete & create
+	// In particular, if we implement hosts update, we can get rid of UpdateHosts
+	if exists {
+		err := s.EnsureTCPLoadBalancerDeleted(name, region)
+		if err != nil {
+			return nil, fmt.Errorf("error deleting existing AWS load balancer: %v", err)
+		}
+	}
 
 	elbClient, err := s.getELBClient(region)
 	if err != nil {

pkg/cloudprovider/providers/fake/fake.go

@@ -56,7 +56,7 @@ type FakeCloud struct {
 	ClusterList   []string
 	MasterName    string
 	ExternalIP    net.IP
-	Balancers     []FakeBalancer
+	Balancers     map[string]FakeBalancer
 	UpdateCalls   []FakeUpdateBalancerCall
 	RouteMap      map[string]*FakeRoute
 	Lock          sync.Mutex
@@ -123,11 +123,14 @@ func (f *FakeCloud) GetTCPLoadBalancer(name, region string) (*api.LoadBalancerSt
 	return status, f.Exists, f.Err
 }
 
-// CreateTCPLoadBalancer is a test-spy implementation of TCPLoadBalancer.CreateTCPLoadBalancer.
+// EnsureTCPLoadBalancer is a test-spy implementation of TCPLoadBalancer.EnsureTCPLoadBalancer.
 // It adds an entry "create" into the internal method call record.
-func (f *FakeCloud) CreateTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinityType api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
+func (f *FakeCloud) EnsureTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinityType api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
 	f.addCall("create")
-	f.Balancers = append(f.Balancers, FakeBalancer{name, region, externalIP, ports, hosts})
+	if f.Balancers == nil {
+		f.Balancers = make(map[string]FakeBalancer)
+	}
+	f.Balancers[name] = FakeBalancer{name, region, externalIP, ports, hosts}
 
 	status := &api.LoadBalancerStatus{}
 	status.Ingress = []api.LoadBalancerIngress{{IP: f.ExternalIP.String()}}

pkg/cloudprovider/providers/gce/gce.go

@@ -348,11 +348,26 @@ func makeFirewallName(name string) string {
 	return fmt.Sprintf("k8s-fw-%s", name)
 }
 
-// CreateTCPLoadBalancer is an implementation of TCPLoadBalancer.CreateTCPLoadBalancer.
+// EnsureTCPLoadBalancer is an implementation of TCPLoadBalancer.EnsureTCPLoadBalancer.
 // TODO(a-robinson): Don't just ignore specified IP addresses. Check if they're
 // owned by the project and available to be used, and use them if they are.
-func (gce *GCECloud) CreateTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinityType api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
-	err := gce.makeTargetPool(name, region, hosts, translateAffinityType(affinityType))
+func (gce *GCECloud) EnsureTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinityType api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
+	glog.V(2).Info("Checking if load balancer already exists: %s", name)
+	_, exists, err := gce.GetTCPLoadBalancer(name, region)
+	if err != nil {
+		return nil, fmt.Errorf("error checking if GCE load balancer already exists: %v", err)
+	}
+
+	// TODO: Implement a more efficient update strategy for common changes than delete & create
+	// In particular, if we implement hosts update, we can get rid of UpdateHosts
+	if exists {
+		err := gce.EnsureTCPLoadBalancerDeleted(name, region)
+		if err != nil {
+			return nil, fmt.Errorf("error deleting existing GCE load balancer: %v", err)
+		}
+	}
+
+	err = gce.makeTargetPool(name, region, hosts, translateAffinityType(affinityType))
 	if err != nil {
 		if !isHTTPErrorCode(err, http.StatusConflict) {
 			return nil, err

pkg/cloudprovider/providers/openstack/openstack.go

@@ -521,8 +521,8 @@ func (lb *LoadBalancer) GetTCPLoadBalancer(name, region string) (*api.LoadBalanc
 // a list of regions (from config) and query/create loadbalancers in
 // each region.
 
-func (lb *LoadBalancer) CreateTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinity api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
-	glog.V(4).Infof("CreateTCPLoadBalancer(%v, %v, %v, %v, %v, %v)", name, region, externalIP, ports, hosts, affinity)
+func (lb *LoadBalancer) EnsureTCPLoadBalancer(name, region string, externalIP net.IP, ports []*api.ServicePort, hosts []string, affinity api.ServiceAffinity) (*api.LoadBalancerStatus, error) {
+	glog.V(4).Infof("EnsureTCPLoadBalancer(%v, %v, %v, %v, %v, %v)", name, region, externalIP, ports, hosts, affinity)
 
 	if len(ports) > 1 {
 		return nil, fmt.Errorf("multiple ports are not yet supported in openstack load balancers")
@@ -538,6 +538,21 @@ func (lb *LoadBalancer) CreateTCPLoadBalancer(name, region string, externalIP ne
 		return nil, fmt.Errorf("unsupported load balancer affinity: %v", affinity)
 	}
 
+	glog.V(2).Info("Checking if openstack load balancer already exists: %s", name)
+	_, exists, err := lb.GetTCPLoadBalancer(name, region)
+	if err != nil {
+		return nil, fmt.Errorf("error checking if openstack load balancer already exists: %v", err)
+	}
+
+	// TODO: Implement a more efficient update strategy for common changes than delete & create
+	// In particular, if we implement hosts update, we can get rid of UpdateHosts
+	if exists {
+		err := lb.EnsureTCPLoadBalancerDeleted(name, region)
+		if err != nil {
+			return nil, fmt.Errorf("error deleting existing openstack load balancer: %v", err)
+		}
+	}
+
 	lbmethod := lb.opts.LBMethod
 	if lbmethod == "" {
 		lbmethod = pools.LBMethodRoundRobin

pkg/controller/service/servicecontroller.go

@@ -335,7 +335,7 @@ func (s *ServiceController) createLoadBalancerIfNeeded(namespacedName types.Name
 			return fmt.Errorf("Failed to persist updated status to apiserver, even after retries. Giving up: %v", err), notRetryable
 		}
 	} else {
-		glog.Infof("Not persisting unchanged LoadBalancerStatus to registry.")
+		glog.V(2).Infof("Not persisting unchanged LoadBalancerStatus to registry.")
 	}
 
 	return nil, notRetryable
@@ -383,7 +383,7 @@ func (s *ServiceController) createExternalLoadBalancer(service *api.Service) err
 		for _, publicIP := range service.Spec.DeprecatedPublicIPs {
 			// TODO: Make this actually work for multiple IPs by using different
 			// names for each. For now, we'll just create the first and break.
-			status, err := s.balancer.CreateTCPLoadBalancer(name, s.zone.Region, net.ParseIP(publicIP),
+			status, err := s.balancer.EnsureTCPLoadBalancer(name, s.zone.Region, net.ParseIP(publicIP),
 				ports, hostsFromNodeList(&nodes), service.Spec.SessionAffinity)
 			if err != nil {
 				return err
@@ -393,7 +393,7 @@ func (s *ServiceController) createExternalLoadBalancer(service *api.Service) err
 			break
 		}
 	} else {
-		status, err := s.balancer.CreateTCPLoadBalancer(name, s.zone.Region, nil,
+		status, err := s.balancer.EnsureTCPLoadBalancer(name, s.zone.Region, nil,
 			ports, hostsFromNodeList(&nodes), service.Spec.SessionAffinity)
 		if err != nil {
 			return err

pkg/controller/service/servicecontroller_test.go

@@ -110,12 +110,22 @@ func TestCreateExternalLoadBalancer(t *testing.T) {
 				t.Errorf("unexpected client actions: %v", actions)
 			}
 		} else {
-			if len(cloud.Balancers) != 1 {
-				t.Errorf("expected one load balancer to be created, got %v", cloud.Balancers)
-			} else if cloud.Balancers[0].Name != controller.loadBalancerName(item.service) ||
-				cloud.Balancers[0].Region != region ||
-				cloud.Balancers[0].Ports[0].Port != item.service.Spec.Ports[0].Port {
-				t.Errorf("created load balancer has incorrect parameters: %v", cloud.Balancers[0])
+			var balancer *fake_cloud.FakeBalancer
+			for k := range cloud.Balancers {
+				if balancer == nil {
+					b := cloud.Balancers[k]
+					balancer = &b
+				} else {
+					t.Errorf("expected one load balancer to be created, got %v", cloud.Balancers)
+					break
+				}
+			}
+			if balancer == nil {
+				t.Errorf("expected one load balancer to be created, got none")
+			} else if balancer.Name != controller.loadBalancerName(item.service) ||
+				balancer.Region != region ||
+				balancer.Ports[0].Port != item.service.Spec.Ports[0].Port {
+				t.Errorf("created load balancer has incorrect parameters: %v", balancer)
 			}
 			actionFound := false
 			for _, action := range actions {