ingress_pod_controller.go

/*
SPDX-License-Identifier: Apache-2.0

Copyright Contributors to the Submariner project.

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 controllers

import (
	"fmt"

	"github.com/pkg/errors"
	"github.com/submariner-io/admiral/pkg/federate"
	"github.com/submariner-io/admiral/pkg/syncer"
	"github.com/submariner-io/admiral/pkg/util"
	submarinerv1 "github.com/submariner-io/submariner/pkg/apis/submariner.io/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/client-go/tools/cache"
	"k8s.io/utils/set"
)

func startIngressPodController(svc *corev1.Service, config *syncer.ResourceSyncerConfig) (*ingressPodController, error) {
	var err error

	_, gvr, err := util.ToUnstructuredResource(&submarinerv1.GlobalIngressIP{}, config.RestMapper)
	if err != nil {
		return nil, errors.Wrap(err, "error converting resource")
	}

	controller := &ingressPodController{
		baseSyncerController:     newBaseSyncerController(),
		svcName:                  svc.Name,
		namespace:                svc.Namespace,
		publishNotReadyAddresses: svc.Spec.PublishNotReadyAddresses,
		ingressIPMap:             set.New[string](),
	}

	labelSelector := labels.Set(svc.Spec.Selector).AsSelector().String()

	controller.resourceSyncer, err = syncer.NewResourceSyncer(&syncer.ResourceSyncerConfig{
		Name:                "Ingress Pod syncer",
		ResourceType:        &corev1.Pod{},
		SourceClient:        config.SourceClient,
		SourceNamespace:     svc.Namespace,
		RestMapper:          config.RestMapper,
		Federator:           federate.NewCreateFederator(config.SourceClient, config.RestMapper, corev1.NamespaceAll),
		Scheme:              config.Scheme,
		Transform:           controller.process,
		SourceLabelSelector: labelSelector,
		ResourcesEquivalent: arePodsEqual,
	})
	if err != nil {
		return nil, errors.Wrap(err, "error creating the syncer")
	}

	if err := controller.Start(); err != nil {
		return nil, errors.Wrap(err, "error starting the syncer")
	}

	selector := map[string]string{
		ServiceRefLabel: svc.Name,
	}

	ingressIPSelector := labels.Set(selector).AsSelector().String()
	ingressIPs := config.SourceClient.Resource(*gvr).Namespace(corev1.NamespaceAll)
	controller.reconcile(ingressIPs, ingressIPSelector, "" /* fieldSelector*/, func(obj *unstructured.Unstructured) runtime.Object {
		podName, exists, _ := unstructured.NestedString(obj.Object, "spec", "podRef", "name")
		if exists {
			return &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name:      podName,
					Namespace: obj.GetNamespace(),
				},
			}
		}

		return nil
	})

	logger.Infof("Created Pod controller for (%s/%s) with selector %q", svc.Namespace, svc.Name, labelSelector)

	return controller, nil
}

func (c *ingressPodController) process(from runtime.Object, _ int, op syncer.Operation) (runtime.Object, bool) {
	pod := from.(*corev1.Pod)
	key, _ := cache.MetaNamespaceKeyFunc(pod)

	ingressIP := &submarinerv1.GlobalIngressIP{
		ObjectMeta: metav1.ObjectMeta{
			Name:      fmt.Sprintf("pod-%.59s", pod.Name),
			Namespace: pod.Namespace,
			Labels: map[string]string{
				ServiceRefLabel: c.svcName,
			},
		},
	}

	if op == syncer.Delete {
		c.ingressIPMap.Delete(ingressIP.Name)
		logger.Infof("ingress Pod %s for service %s deleted", key, c.svcName)

		return ingressIP, false
	}

	if c.ingressIPMap.Has(ingressIP.Name) || pod.Status.PodIP == "" ||
		(!c.publishNotReadyAddresses && pod.Status.Phase != corev1.PodRunning) {
		// Avoid assigning ingressIPs to pods that are not ready with an endpoint IP
		return nil, false
	}

	logger.Infof("%q ingress Pod %s for service %s", op, key, c.svcName)

	ingressIP.ObjectMeta.Annotations = map[string]string{
		headlessSvcPodIP: pod.Status.PodIP,
	}

	ingressIP.Spec = submarinerv1.GlobalIngressIPSpec{
		Target:     submarinerv1.HeadlessServicePod,
		ServiceRef: &corev1.LocalObjectReference{Name: c.svcName},
		PodRef:     &corev1.LocalObjectReference{Name: pod.Name},
	}

	c.ingressIPMap.Insert(ingressIP.Name)

	return ingressIP, false
}

func arePodsEqual(obj1, obj2 *unstructured.Unstructured) bool {
	phase1, _, _ := unstructured.NestedString(obj1.Object, "status", "phase")
	phase2, _, _ := unstructured.NestedString(obj2.Object, "status", "phase")
	podIP1, _, _ := unstructured.NestedString(obj1.Object, "status", "podIP")
	podIP2, _, _ := unstructured.NestedString(obj2.Object, "status", "podIP")

	return phase1 == phase2 && podIP1 == podIP2
}