service_change_tracker.go

/*
Copyright 2021 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package userspacelin

import (
	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/tools/events"
	klog "k8s.io/klog/v2"

	//	"sigs.k8s.io/kpng/backends/userspacelin/metrics"

	// "k8s.io/kubernetes/pkg/proxy/metrics"
	"sigs.k8s.io/kpng/api/localv1"
)

type userspaceServiceChange struct {
	current  *localv1.Service
	previous *localv1.Service
}

type UserspaceServiceChangeTracker struct {
	// items maps a service to its serviceChangee (which is just a map[servicePortName]servicePort)
	items map[types.NamespacedName]*userspaceServiceChange

	// processServiceMapChange processServiceMapChangeFunc
	ipFamily v1.IPFamily

	recorder events.EventRecorder
}

// Update updates given service's change map based on the <previous, current> service pair.  It returns true if items changed,
// otherwise return false.  Update can be used to add/update/delete items of ServiceChangeMap.  For example,
// Add item
//   - pass <nil, service> as the <previous, current> pair.
//
// Update item
//   - pass <oldService, service> as the <previous, current> pair.
//
// Delete item
//   - pass <service, nil> as the <previous, current> pair.
func (sct *UserspaceServiceChangeTracker) Update(current *localv1.Service) bool {
	svc := current
	if svc == nil {
		return false
	}
	//metrics.ServiceChangesTotal.Inc()
	namespacedName := types.NamespacedName{Namespace: svc.Namespace, Name: svc.Name}
	var change *userspaceServiceChange
	var ok bool
	if change, ok = sct.items[namespacedName]; !ok {
		change = &userspaceServiceChange{}
		sct.items[namespacedName] = change
	}

	rcc := &userspaceServiceChange{
		previous: sct.items[namespacedName].current,
		current:  current,
	}
	// TODO make sure i did the pointers right here?
	*change = *rcc

	// *change = sct.serviceToServiceMap(current)
	// klog.V(2).Infof("Service %s updated: %d ports", namespacedName, len(*change))
	//metrics.ServiceChangesPending.Set(float64(len(sct.items)))
	return len(sct.items) > 0
}

func (sct *UserspaceServiceChangeTracker) Delete(namespace, name string) bool {
	//metrics.ServiceChangesTotal.Inc()
	namespacedName := types.NamespacedName{Namespace: namespace, Name: name}
	sct.items[namespacedName] = nil
	klog.V(2).Infof("Service %s updated for delete", namespacedName)
	//metrics.ServiceChangesPending.Set(float64(len(sct.items)))
	return len(sct.items) > 0
}

// ServicePortName carries a namespace + name + portname.  This is the unique
// identifier for a load-balanced service.
type ServicePortName struct {
	types.NamespacedName
	Port     string
	Protocol localv1.Protocol
	PortName string // FYI Jay added this, because we needed it for the BuildPortsToEndpointsMap function by KPNG
}

/**
// serviceToServiceMap translates a single Service object to a ServiceMap.
//
// NOTE: service object should NOT be modified.
func (sct *UserspaceServiceChangeTracker) serviceToServiceMap(service *kpng.Service) userspaceServiceChange {
	if service == nil {
		return nil
	}
	clusterIP := GetClusterIPByFamily(sct.ipFamily, service)
	if clusterIP == "" {
		return nil
	}
	serviceMap := make(userspaceServiceChange)
	svcName := types.NamespacedName{Namespace: service.Namespace, Name: service.Name}
	for i := range service.Ports {
		servicePort := service.Ports[i]
		svcPortName := ServicePortName{NamespacedName: svcName, Port: servicePort.Name, Protocol: servicePort.Protocol}
		baseSvcInfo := sct.newBaseServiceInfo(servicePort, service)
		if sct.makeServiceInfo != nil {
			serviceMap[svcPortName] = sct.makeServiceInfo(servicePort, service, baseSvcInfo)
		} else {
			serviceMap[svcPortName] = baseSvcInfo
		}
	}
	return serviceMap
}
**/