func startRouteController()

in app/core.go [102:146]
33 lines of code
9 McCabe index (conditional complexity)

func startRouteController(ctx context.Context, initContext ControllerInitContext, completedConfig *config.CompletedConfig, cloud cloudprovider.Interface) (controller.Interface, bool, error) {
	if !completedConfig.ComponentConfig.KubeCloudShared.ConfigureCloudRoutes {
		klog.Infof("Will not configure cloud provider routes, --configure-cloud-routes: %v", completedConfig.ComponentConfig.KubeCloudShared.ConfigureCloudRoutes)
		return nil, false, nil
	}

	// If CIDRs should be allocated for pods and set on the CloudProvider, then start the route controller
	routes, ok := cloud.Routes()
	if !ok {
		klog.Warning("--configure-cloud-routes is set, but cloud provider does not support routes. Will not configure cloud provider routes.")
		return nil, false, nil
	}

	// failure: bad cidrs in config
	clusterCIDRs, dualStack, err := processCIDRs(completedConfig.ComponentConfig.KubeCloudShared.ClusterCIDR)
	if err != nil {
		return nil, false, err
	}

	// failure: more than one cidr and dual stack is not enabled
	if len(clusterCIDRs) > 1 && !utilfeature.DefaultFeatureGate.Enabled(features.IPv6DualStack) {
		return nil, false, fmt.Errorf("len of ClusterCIDRs==%v and dualstack feature is not enabled", len(clusterCIDRs))
	}

	// failure: more than one cidr but they are not configured as dual stack
	if len(clusterCIDRs) > 1 && !dualStack {
		return nil, false, fmt.Errorf("len of ClusterCIDRs==%v and they are not configured as dual stack (at least one from each IPFamily", len(clusterCIDRs))
	}

	// failure: more than cidrs is not allowed even with dual stack
	if len(clusterCIDRs) > 2 {
		return nil, false, fmt.Errorf("length of clusterCIDRs is:%v more than max allowed of 2", len(clusterCIDRs))
	}

	routeController := routecontroller.New(
		routes,
		completedConfig.ClientBuilder.ClientOrDie(initContext.ClientName),
		completedConfig.SharedInformers.Core().V1().Nodes(),
		completedConfig.ComponentConfig.KubeCloudShared.ClusterName,
		clusterCIDRs,
	)
	go routeController.Run(ctx, completedConfig.ComponentConfig.KubeCloudShared.RouteReconciliationPeriod.Duration)

	return nil, true, nil
}