Ensure health check exists before creating target pool

pkg/cloudprovider/providers/gce/gce.go

@@ -608,6 +608,8 @@ func (gce *GCECloud) EnsureLoadBalancer(clusterName string, apiService *api.Serv
 	// an IP, we assume they are managing it themselves.  Otherwise, we will
 	// release the IP in case of early-terminating failure or upon successful
 	// creating of the LB.
+	// TODO(#36535): boil this logic down into a set of component functions
+	// and key the flag values off of errors returned.
 	isUserOwnedIP := false // if this is set, we never release the IP
 	isSafeToReleaseIP := false
 	defer func() {
@@ -735,7 +737,7 @@ func (gce *GCECloud) EnsureLoadBalancer(clusterName string, apiService *api.Serv
 		return nil, fmt.Errorf("Error checking HTTP health check %s: %v", loadBalancerName, err)
 	}
 	if path, healthCheckNodePort := apiservice.GetServiceHealthCheckPathPort(apiService); path != "" {
-		glog.V(4).Infof("service %v needs health checks on :%d/%s)", apiService.Name, healthCheckNodePort, path)
+		glog.V(4).Infof("service %v (%v) needs health checks on :%d%s)", apiService.Name, loadBalancerName, healthCheckNodePort, path)
 		if err != nil {
 			// This logic exists to detect a transition for a pre-existing service and turn on
 			// the tpNeedsUpdate flag to delete/recreate fwdrule/tpool adding the health check
@@ -1080,13 +1082,18 @@ func (gce *GCECloud) createTargetPool(name, serviceName, region string, hosts []
 	for _, host := range hosts {
 		instances = append(instances, makeHostURL(gce.projectID, host.Zone, host.Name))
 	}
+	// health check management is coupled with targetPools to prevent leaks. A
+	// target pool is the only thing that requires a health check, so we delete
+	// associated checks on teardown, and ensure checks on setup.
 	hcLinks := []string{}
 	if hc != nil {
+		var err error
+		if hc, err = gce.ensureHttpHealthCheck(name, hc.RequestPath, int32(hc.Port)); err != nil || hc == nil {
+			return fmt.Errorf("Failed to ensure health check for %v port %d path %v: %v", name, hc.Port, hc.RequestPath, err)
+		}
 		hcLinks = append(hcLinks, hc.SelfLink)
 	}
-	if len(hcLinks) > 0 {
-		glog.Infof("Creating targetpool %v with healthchecking", name)
-	}
+	glog.Infof("Creating targetpool %v with %d healthchecks", name, len(hcLinks))
 	pool := &compute.TargetPool{
 		Name:            name,
 		Description:     fmt.Sprintf(`{"kubernetes.io/service-name":"%s"}`, serviceName),