managedseed.go

// Copyright (c) 2021 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the LICENSE file
//
// 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 managedseed

import (
	"context"
	"fmt"
	"sync"
	"time"

	gardencorev1beta1 "github.com/gardener/gardener/pkg/apis/core/v1beta1"
	gardencorev1beta1constants "github.com/gardener/gardener/pkg/apis/core/v1beta1/constants"
	seedmanagementv1alpha1 "github.com/gardener/gardener/pkg/apis/seedmanagement/v1alpha1"
	"github.com/gardener/gardener/pkg/client/kubernetes"
	"github.com/gardener/gardener/pkg/client/kubernetes/clientmap"
	"github.com/gardener/gardener/pkg/client/kubernetes/clientmap/keys"
	"github.com/gardener/gardener/pkg/controllerutils"
	"github.com/gardener/gardener/pkg/gardenlet/apis/config"
	confighelper "github.com/gardener/gardener/pkg/gardenlet/apis/config/helper"
	"github.com/gardener/gardener/pkg/utils/imagevector"
	kutils "github.com/gardener/gardener/pkg/utils/kubernetes"

	"github.com/go-logr/logr"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/client-go/tools/cache"
	"k8s.io/client-go/tools/record"
	"k8s.io/client-go/util/workqueue"
	"k8s.io/utils/pointer"
	runtimecache "sigs.k8s.io/controller-runtime/pkg/cache"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
)

const (
	// ControllerName is the name of this controller.
	ControllerName = "managedseed"

	// GardenletDefaultKubeconfigSecretName is the default name for the field in the Gardenlet component configuration
	// .gardenClientConnection.KubeconfigSecret.Name
	GardenletDefaultKubeconfigSecretName = "gardenlet-kubeconfig"
	// GardenletDefaultKubeconfigBootstrapSecretName is the default name for the field in the Gardenlet component configuration
	// .gardenClientConnection.BootstrapKubeconfig.Name
	GardenletDefaultKubeconfigBootstrapSecretName = "gardenlet-kubeconfig-bootstrap"
)

// Controller controls ManagedSeeds.
type Controller struct {
	log logr.Logger

	gardenClient kubernetes.Interface
	config       *config.GardenletConfiguration
	reconciler   reconcile.Reconciler

	managedSeedInformer runtimecache.Informer
	seedInformer        runtimecache.Informer

	managedSeedQueue workqueue.RateLimitingInterface

	numberOfRunningWorkers int
	workerCh               chan int
}

// NewManagedSeedController creates a new Gardener controller for ManagedSeeds.
func NewManagedSeedController(
	ctx context.Context,
	log logr.Logger,
	clientMap clientmap.ClientMap,
	config *config.GardenletConfiguration,
	imageVector imagevector.ImageVector,
	recorder record.EventRecorder,
) (
	*Controller,
	error,
) {
	log = log.WithName(ControllerName)

	gardenClient, err := clientMap.GetClient(ctx, keys.ForGarden())
	if err != nil {
		return nil, fmt.Errorf("could not get garden client: %w", err)
	}

	managedSeedInformer, err := gardenClient.Cache().GetInformer(ctx, &seedmanagementv1alpha1.ManagedSeed{})
	if err != nil {
		return nil, fmt.Errorf("could not get ManagedSeed informer: %w", err)
	}

	seedInformer, err := gardenClient.Cache().GetInformer(ctx, &gardencorev1beta1.Seed{})
	if err != nil {
		return nil, fmt.Errorf("could not get Seed informer: %w", err)
	}

	var (
		valuesHelper = NewValuesHelper(config, imageVector)
		actuator     = newActuator(gardenClient, clientMap, valuesHelper, recorder)
	)

	return &Controller{
		log:                 log,
		gardenClient:        gardenClient,
		config:              config,
		reconciler:          newReconciler(gardenClient, actuator, config.Controllers.ManagedSeed),
		managedSeedInformer: managedSeedInformer,
		seedInformer:        seedInformer,
		managedSeedQueue:    workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "ManagedSeed"),
		workerCh:            make(chan int),
	}, nil
}

// Run runs the Controller until the given context is cancelled.
func (c *Controller) Run(ctx context.Context, workers int) {
	var waitGroup sync.WaitGroup

	c.managedSeedInformer.AddEventHandler(cache.FilteringResourceEventHandler{
		FilterFunc: controllerutils.ManagedSeedFilterFunc(ctx, c.gardenClient.Cache(), confighelper.SeedNameFromSeedConfig(c.config.SeedConfig)),
		Handler: cache.ResourceEventHandlerFuncs{
			AddFunc:    c.managedSeedAdd,
			UpdateFunc: c.managedSeedUpdate,
			DeleteFunc: c.managedSeedDelete,
		},
	})

	// Add event handler for controlled seeds
	c.seedInformer.AddEventHandler(cache.FilteringResourceEventHandler{
		FilterFunc: controllerutils.SeedOfManagedSeedFilterFunc(ctx, c.gardenClient.Cache(), confighelper.SeedNameFromSeedConfig(c.config.SeedConfig)),
		Handler: &kutils.ControlledResourceEventHandler{
			ControllerTypes: []kutils.ControllerType{
				{
					Type:      &seedmanagementv1alpha1.ManagedSeed{},
					Namespace: pointer.String(gardencorev1beta1constants.GardenNamespace),
					NameFunc:  func(obj client.Object) string { return obj.GetName() },
				},
			},
			Ctx:                        ctx,
			Reader:                     c.gardenClient.Cache(),
			ControllerPredicateFactory: kutils.ControllerPredicateFactoryFunc(c.filterSeed),
			Enqueuer:                   kutils.EnqueuerFunc(func(obj client.Object) { c.managedSeedAdd(obj) }),
			Scheme:                     kubernetes.GardenScheme,
			Logger:                     c.log,
		},
	})

	if !cache.WaitForCacheSync(ctx.Done(), c.managedSeedInformer.HasSynced, c.seedInformer.HasSynced) {
		c.log.Error(wait.ErrWaitTimeout, "Timed out waiting for caches to sync")
		return
	}

	// Count number of running workers
	go func() {
		for res := range c.workerCh {
			c.numberOfRunningWorkers += res
		}
	}()

	c.log.Info("ManagedSeed controller initialized")

	for i := 0; i < workers; i++ {
		controllerutils.CreateWorker(ctx, c.managedSeedQueue, "ManagedSeed", c.reconciler, &waitGroup, c.workerCh, controllerutils.WithLogger(c.log))
	}

	// Shutdown handling
	<-ctx.Done()
	c.managedSeedQueue.ShutDown()

	for {
		if c.managedSeedQueue.Len() == 0 && c.numberOfRunningWorkers == 0 {
			c.log.V(1).Info("No running ManagedSeed worker and no items left in the queues. Terminated ManagedSeed controller")
			break
		}
		c.log.V(1).Info("Waiting for ManagedSeed workers to finish", "numberOfRunningWorkers", c.numberOfRunningWorkers, "queueLength", c.managedSeedQueue.Len())
		time.Sleep(5 * time.Second)
	}

	waitGroup.Wait()
}