Annotation for opting into backend sharing; Use hash suffix for sharing; Fix resource GC

pkg/cloudprovider/providers/gce/gce_annotations.go

@@ -21,12 +21,17 @@ import "k8s.io/kubernetes/pkg/api/v1"
 type LoadBalancerType string
 
 const (
-	// ServiceAnnotationLoadBalancerType is the annotation used on a service with type LoadBalancer
+	// ServiceAnnotationLoadBalancerType is annotated on a service with type LoadBalancer
 	// dictates what specific kind of GCP LB should be assembled.
 	// Currently, only "internal" is supported.
 	ServiceAnnotationLoadBalancerType = "cloud.google.com/load-balancer-type"
 
 	LBTypeInternal LoadBalancerType = "internal"
+
+	// ServiceAnnotationInternalBackendShare is annotated on a service with "true" when users
+	// want to share GCP Backend Services for a set of internal load balancers.
+	// ALPHA feature - this may be removed in a future release.
+	ServiceAnnotationILBBackendShare = "cloud.google.com/load-balancer-backend-share"
 )
 
 // GetLoadBalancerAnnotationType returns the type of GCP load balancer which should be assembled.
@@ -49,3 +54,12 @@ func GetLoadBalancerAnnotationType(service *v1.Service) (LoadBalancerType, bool)
 		return v, false
 	}
 }
+
+func GetLoadBalancerAnnotationBackendShare(service *v1.Service) bool {
+	l, exists := service.Annotations[ServiceAnnotationILBBackendShare]
+	if exists && l == "true" {
+		return true
+	}
+
+	return false
+}

pkg/cloudprovider/providers/gce/gce_loadbalancer_naming.go

@@ -17,6 +17,8 @@ limitations under the License.
 package gce
 
 import (
+	"crypto/sha1"
+	"encoding/hex"
 	"fmt"
 	"strings"
 
@@ -33,15 +35,16 @@ func makeInstanceGroupName(clusterID string) string {
 
 func makeBackendServiceName(loadBalancerName, clusterID string, shared bool, scheme lbScheme, protocol v1.Protocol, svcAffinity v1.ServiceAffinity) string {
 	if shared {
-		affinity := ""
-		switch svcAffinity {
-		case v1.ServiceAffinityClientIP:
-			affinity = "clientip"
-		default:
-			affinity = "noaffinity"
-		}
-
-		return fmt.Sprintf("k8s-%s-%s-%s-%s", clusterID, strings.ToLower(string(scheme)), strings.ToLower(string(protocol)), affinity)
+		hash := sha1.New()
+
+		// For every non-nil option, hash its value. Currently, only service affinity is relevant.
+		hash.Write([]byte(string(svcAffinity)))
+
+		hashed := hex.EncodeToString(hash.Sum(nil))
+		hashed = hashed[:16]
+
+		// 3 + 1 + 16 + 1 + 8 + 1 + 3 + 16
+		return fmt.Sprintf("k8s-%s-%s-%s-nmv1-%s", clusterID, strings.ToLower(string(scheme)), strings.ToLower(string(protocol)), hashed)
 	}
 	return loadBalancerName
 }
@@ -54,11 +57,11 @@ func makeHealthCheckName(loadBalancerName, clusterID string, shared bool) string
 	return loadBalancerName
 }
 
-func makeHealthCheckFirewallkNameFromHC(healthCheckName string) string {
+func makeHealthCheckFirewallNameFromHC(healthCheckName string) string {
 	return healthCheckName + "-hc"
 }
 
-func makeHealthCheckFirewallkName(loadBalancerName, clusterID string, shared bool) string {
+func makeHealthCheckFirewallName(loadBalancerName, clusterID string, shared bool) string {
 	if shared {
 		return fmt.Sprintf("k8s-%s-node-hc", clusterID)
 	}