/*
Copyright 2016 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 app implements a server that runs a set of active
// components.  This includes replication controllers, service endpoints and
// nodes.
//
package app

import (
	"fmt"
	"net"
	"strings"
	"time"

	"github.com/golang/glog"

	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/apimachinery/pkg/runtime/schema"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	"k8s.io/client-go/discovery"
	cacheddiscovery "k8s.io/client-go/discovery/cached"
	"k8s.io/client-go/dynamic"
	clientset "k8s.io/client-go/kubernetes"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/controller"
	endpointcontroller "k8s.io/kubernetes/pkg/controller/endpoint"
	"k8s.io/kubernetes/pkg/controller/garbagecollector"
	namespacecontroller "k8s.io/kubernetes/pkg/controller/namespace"
	nodecontroller "k8s.io/kubernetes/pkg/controller/node"
	"k8s.io/kubernetes/pkg/controller/node/ipam"
	"k8s.io/kubernetes/pkg/controller/podgc"
	replicationcontroller "k8s.io/kubernetes/pkg/controller/replication"
	resourcequotacontroller "k8s.io/kubernetes/pkg/controller/resourcequota"
	routecontroller "k8s.io/kubernetes/pkg/controller/route"
	servicecontroller "k8s.io/kubernetes/pkg/controller/service"
	serviceaccountcontroller "k8s.io/kubernetes/pkg/controller/serviceaccount"
	ttlcontroller "k8s.io/kubernetes/pkg/controller/ttl"
	"k8s.io/kubernetes/pkg/controller/volume/attachdetach"
	"k8s.io/kubernetes/pkg/controller/volume/expand"
	persistentvolumecontroller "k8s.io/kubernetes/pkg/controller/volume/persistentvolume"
	"k8s.io/kubernetes/pkg/features"
	quotainstall "k8s.io/kubernetes/pkg/quota/install"
	"k8s.io/kubernetes/pkg/util/metrics"
)

func startServiceController(ctx ControllerContext) (bool, error) {
	serviceController, err := servicecontroller.New(
		ctx.Cloud,
		ctx.ClientBuilder.ClientOrDie("service-controller"),
		ctx.InformerFactory.Core().V1().Services(),
		ctx.InformerFactory.Core().V1().Nodes(),
		ctx.Options.ClusterName,
	)
	if err != nil {
		glog.Errorf("Failed to start service controller: %v", err)
		return false, nil
	}
	go serviceController.Run(ctx.Stop, int(ctx.Options.ConcurrentServiceSyncs))
	return true, nil
}

func startNodeController(ctx ControllerContext) (bool, error) {
	var clusterCIDR *net.IPNet
	var err error
	if len(strings.TrimSpace(ctx.Options.ClusterCIDR)) != 0 {
		_, clusterCIDR, err = net.ParseCIDR(ctx.Options.ClusterCIDR)
		if err != nil {
			glog.Warningf("Unsuccessful parsing of cluster CIDR %v: %v", ctx.Options.ClusterCIDR, err)
		}
	}

	var serviceCIDR *net.IPNet
	if len(strings.TrimSpace(ctx.Options.ServiceCIDR)) != 0 {
		_, serviceCIDR, err = net.ParseCIDR(ctx.Options.ServiceCIDR)
		if err != nil {
			glog.Warningf("Unsuccessful parsing of service CIDR %v: %v", ctx.Options.ServiceCIDR, err)
		}
	}

	nodeController, err := nodecontroller.NewNodeController(
		ctx.InformerFactory.Core().V1().Pods(),
		ctx.InformerFactory.Core().V1().Nodes(),
		ctx.InformerFactory.Extensions().V1beta1().DaemonSets(),
		ctx.Cloud,
		ctx.ClientBuilder.ClientOrDie("node-controller"),
		ctx.Options.PodEvictionTimeout.Duration,
		ctx.Options.NodeEvictionRate,
		ctx.Options.SecondaryNodeEvictionRate,
		ctx.Options.LargeClusterSizeThreshold,
		ctx.Options.UnhealthyZoneThreshold,
		ctx.Options.NodeMonitorGracePeriod.Duration,
		ctx.Options.NodeStartupGracePeriod.Duration,
		ctx.Options.NodeMonitorPeriod.Duration,
		clusterCIDR,
		serviceCIDR,
		int(ctx.Options.NodeCIDRMaskSize),
		ctx.Options.AllocateNodeCIDRs,
		ipam.CIDRAllocatorType(ctx.Options.CIDRAllocatorType),
		ctx.Options.EnableTaintManager,
		utilfeature.DefaultFeatureGate.Enabled(features.TaintBasedEvictions),
		utilfeature.DefaultFeatureGate.Enabled(features.TaintNodesByCondition),
	)
	if err != nil {
		return true, err
	}
	go nodeController.Run(ctx.Stop)
	return true, nil
}

func startRouteController(ctx ControllerContext) (bool, error) {
	_, clusterCIDR, err := net.ParseCIDR(ctx.Options.ClusterCIDR)
	if err != nil {
		glog.Warningf("Unsuccessful parsing of cluster CIDR %v: %v", ctx.Options.ClusterCIDR, err)
	}
	if !ctx.Options.AllocateNodeCIDRs || !ctx.Options.ConfigureCloudRoutes {
		glog.Infof("Will not configure cloud provider routes for allocate-node-cidrs: %v, configure-cloud-routes: %v.", ctx.Options.AllocateNodeCIDRs, ctx.Options.ConfigureCloudRoutes)
		return false, nil
	}
	if ctx.Cloud == nil {
		glog.Warning("configure-cloud-routes is set, but no cloud provider specified. Will not configure cloud provider routes.")
		return false, nil
	}
	routes, ok := ctx.Cloud.Routes()
	if !ok {
		glog.Warning("configure-cloud-routes is set, but cloud provider does not support routes. Will not configure cloud provider routes.")
		return false, nil
	}
	routeController := routecontroller.New(routes, ctx.ClientBuilder.ClientOrDie("route-controller"), ctx.InformerFactory.Core().V1().Nodes(), ctx.Options.ClusterName, clusterCIDR)
	go routeController.Run(ctx.Stop, ctx.Options.RouteReconciliationPeriod.Duration)
	return true, nil
}

func startPersistentVolumeBinderController(ctx ControllerContext) (bool, error) {
	params := persistentvolumecontroller.ControllerParameters{
		KubeClient:                ctx.ClientBuilder.ClientOrDie("persistent-volume-binder"),
		SyncPeriod:                ctx.Options.PVClaimBinderSyncPeriod.Duration,
		VolumePlugins:             ProbeControllerVolumePlugins(ctx.Cloud, ctx.Options.VolumeConfiguration),
		Cloud:                     ctx.Cloud,
		ClusterName:               ctx.Options.ClusterName,
		VolumeInformer:            ctx.InformerFactory.Core().V1().PersistentVolumes(),
		ClaimInformer:             ctx.InformerFactory.Core().V1().PersistentVolumeClaims(),
		ClassInformer:             ctx.InformerFactory.Storage().V1().StorageClasses(),
		EnableDynamicProvisioning: ctx.Options.VolumeConfiguration.EnableDynamicProvisioning,
	}
	volumeController, volumeControllerErr := persistentvolumecontroller.NewController(params)
	if volumeControllerErr != nil {
		return true, fmt.Errorf("failed to construct persistentvolume controller: %v", volumeControllerErr)
	}
	go volumeController.Run(ctx.Stop)
	return true, nil
}

func startAttachDetachController(ctx ControllerContext) (bool, error) {
	if ctx.Options.ReconcilerSyncLoopPeriod.Duration < time.Second {
		return true, fmt.Errorf("Duration time must be greater than one second as set via command line option reconcile-sync-loop-period.")
	}
	attachDetachController, attachDetachControllerErr :=
		attachdetach.NewAttachDetachController(
			ctx.ClientBuilder.ClientOrDie("attachdetach-controller"),
			ctx.InformerFactory.Core().V1().Pods(),
			ctx.InformerFactory.Core().V1().Nodes(),
			ctx.InformerFactory.Core().V1().PersistentVolumeClaims(),
			ctx.InformerFactory.Core().V1().PersistentVolumes(),
			ctx.Cloud,
			ProbeAttachableVolumePlugins(),
			GetDynamicPluginProber(ctx.Options.VolumeConfiguration),
			ctx.Options.DisableAttachDetachReconcilerSync,
			ctx.Options.ReconcilerSyncLoopPeriod.Duration,
			attachdetach.DefaultTimerConfig,
		)
	if attachDetachControllerErr != nil {
		return true, fmt.Errorf("failed to start attach/detach controller: %v", attachDetachControllerErr)
	}
	go attachDetachController.Run(ctx.Stop)
	return true, nil
}

func startVolumeExpandController(ctx ControllerContext) (bool, error) {
	if utilfeature.DefaultFeatureGate.Enabled(features.ExpandPersistentVolumes) {
		expandController, expandControllerErr := expand.NewExpandController(
			ctx.ClientBuilder.ClientOrDie("expand-controller"),
			ctx.InformerFactory.Core().V1().PersistentVolumeClaims(),
			ctx.InformerFactory.Core().V1().PersistentVolumes(),
			ctx.Cloud,
			ProbeExpandableVolumePlugins(ctx.Options.VolumeConfiguration))

		if expandControllerErr != nil {
			return true, fmt.Errorf("Failed to start volume expand controller : %v", expandControllerErr)
		}
		go expandController.Run(ctx.Stop)
		return true, nil
	}
	return false, nil
}

func startEndpointController(ctx ControllerContext) (bool, error) {
	go endpointcontroller.NewEndpointController(
		ctx.InformerFactory.Core().V1().Pods(),
		ctx.InformerFactory.Core().V1().Services(),
		ctx.InformerFactory.Core().V1().Endpoints(),
		ctx.ClientBuilder.ClientOrDie("endpoint-controller"),
	).Run(int(ctx.Options.ConcurrentEndpointSyncs), ctx.Stop)
	return true, nil
}

func startReplicationController(ctx ControllerContext) (bool, error) {
	go replicationcontroller.NewReplicationManager(
		ctx.InformerFactory.Core().V1().Pods(),
		ctx.InformerFactory.Core().V1().ReplicationControllers(),
		ctx.ClientBuilder.ClientOrDie("replication-controller"),
		replicationcontroller.BurstReplicas,
	).Run(int(ctx.Options.ConcurrentRCSyncs), ctx.Stop)
	return true, nil
}

func startPodGCController(ctx ControllerContext) (bool, error) {
	go podgc.NewPodGC(
		ctx.ClientBuilder.ClientOrDie("pod-garbage-collector"),
		ctx.InformerFactory.Core().V1().Pods(),
		int(ctx.Options.TerminatedPodGCThreshold),
	).Run(ctx.Stop)
	return true, nil
}

func startResourceQuotaController(ctx ControllerContext) (bool, error) {
	resourceQuotaControllerClient := ctx.ClientBuilder.ClientOrDie("resourcequota-controller")
	resourceQuotaRegistry := quotainstall.NewRegistry(resourceQuotaControllerClient, ctx.InformerFactory)
	groupKindsToReplenish := []schema.GroupKind{
		api.Kind("Pod"),
		api.Kind("Service"),
		api.Kind("ReplicationController"),
		api.Kind("PersistentVolumeClaim"),
		api.Kind("Secret"),
		api.Kind("ConfigMap"),
	}
	resourceQuotaControllerOptions := &resourcequotacontroller.ResourceQuotaControllerOptions{
		QuotaClient:               resourceQuotaControllerClient.Core(),
		ResourceQuotaInformer:     ctx.InformerFactory.Core().V1().ResourceQuotas(),
		ResyncPeriod:              controller.StaticResyncPeriodFunc(ctx.Options.ResourceQuotaSyncPeriod.Duration),
		Registry:                  resourceQuotaRegistry,
		ControllerFactory:         resourcequotacontroller.NewReplenishmentControllerFactory(ctx.InformerFactory),
		ReplenishmentResyncPeriod: ResyncPeriod(&ctx.Options),
		GroupKindsToReplenish:     groupKindsToReplenish,
	}
	if resourceQuotaControllerClient.Core().RESTClient().GetRateLimiter() != nil {
		metrics.RegisterMetricAndTrackRateLimiterUsage("resource_quota_controller", resourceQuotaControllerClient.Core().RESTClient().GetRateLimiter())
	}

	go resourcequotacontroller.NewResourceQuotaController(
		resourceQuotaControllerOptions,
	).Run(int(ctx.Options.ConcurrentResourceQuotaSyncs), ctx.Stop)
	return true, nil
}

func startNamespaceController(ctx ControllerContext) (bool, error) {
	// TODO: should use a dynamic RESTMapper built from the discovery results.
	restMapper := api.Registry.RESTMapper()

	// the namespace cleanup controller is very chatty.  It makes lots of discovery calls and then it makes lots of delete calls
	// the ratelimiter negatively affects its speed.  Deleting 100 total items in a namespace (that's only a few of each resource
	// including events), takes ~10 seconds by default.
	nsKubeconfig := ctx.ClientBuilder.ConfigOrDie("namespace-controller")
	nsKubeconfig.QPS *= 10
	nsKubeconfig.Burst *= 10
	namespaceKubeClient := clientset.NewForConfigOrDie(nsKubeconfig)
	namespaceClientPool := dynamic.NewClientPool(nsKubeconfig, restMapper, dynamic.LegacyAPIPathResolverFunc)

	discoverResourcesFn := namespaceKubeClient.Discovery().ServerPreferredNamespacedResources

	namespaceController := namespacecontroller.NewNamespaceController(
		namespaceKubeClient,
		namespaceClientPool,
		discoverResourcesFn,
		ctx.InformerFactory.Core().V1().Namespaces(),
		ctx.Options.NamespaceSyncPeriod.Duration,
		v1.FinalizerKubernetes,
	)
	go namespaceController.Run(int(ctx.Options.ConcurrentNamespaceSyncs), ctx.Stop)

	return true, nil
}

func startServiceAccountController(ctx ControllerContext) (bool, error) {
	go serviceaccountcontroller.NewServiceAccountsController(
		ctx.InformerFactory.Core().V1().ServiceAccounts(),
		ctx.InformerFactory.Core().V1().Namespaces(),
		ctx.ClientBuilder.ClientOrDie("service-account-controller"),
		serviceaccountcontroller.DefaultServiceAccountsControllerOptions(),
	).Run(1, ctx.Stop)
	return true, nil
}

func startTTLController(ctx ControllerContext) (bool, error) {
	go ttlcontroller.NewTTLController(
		ctx.InformerFactory.Core().V1().Nodes(),
		ctx.ClientBuilder.ClientOrDie("ttl-controller"),
	).Run(5, ctx.Stop)
	return true, nil
}

func startGarbageCollectorController(ctx ControllerContext) (bool, error) {
	if !ctx.Options.EnableGarbageCollector {
		return false, nil
	}

	gcClientset := ctx.ClientBuilder.ClientOrDie("generic-garbage-collector")

	// Use a discovery client capable of being refreshed.
	discoveryClient := cacheddiscovery.NewMemCacheClient(gcClientset.Discovery())
	restMapper := discovery.NewDeferredDiscoveryRESTMapper(discoveryClient, meta.InterfacesForUnstructured)
	restMapper.Reset()

	config := ctx.ClientBuilder.ConfigOrDie("generic-garbage-collector")
	config.ContentConfig = dynamic.ContentConfig()
	// TODO: Make NewMetadataCodecFactory support arbitrary (non-compiled)
	// resource types. Otherwise we'll be storing full Unstructured data in our
	// caches for custom resources. Consider porting it to work with
	// metav1alpha1.PartialObjectMetadata.
	metaOnlyClientPool := dynamic.NewClientPool(config, restMapper, dynamic.LegacyAPIPathResolverFunc)
	clientPool := dynamic.NewClientPool(config, restMapper, dynamic.LegacyAPIPathResolverFunc)

	// Get an initial set of deletable resources to prime the garbage collector.
	deletableResources := garbagecollector.GetDeletableResources(discoveryClient)
	ignoredResources := make(map[schema.GroupResource]struct{})
	for _, r := range ctx.Options.GCIgnoredResources {
		ignoredResources[schema.GroupResource{Group: r.Group, Resource: r.Resource}] = struct{}{}
	}
	garbageCollector, err := garbagecollector.NewGarbageCollector(
		metaOnlyClientPool,
		clientPool,
		restMapper,
		deletableResources,
		ignoredResources,
		ctx.InformerFactory,
		ctx.InformersStarted,
	)
	if err != nil {
		return true, fmt.Errorf("Failed to start the generic garbage collector: %v", err)
	}

	// Start the garbage collector.
	workers := int(ctx.Options.ConcurrentGCSyncs)
	go garbageCollector.Run(workers, ctx.Stop)

	// Periodically refresh the RESTMapper with new discovery information and sync
	// the garbage collector.
	go garbageCollector.Sync(gcClientset.Discovery(), 30*time.Second, ctx.Stop)

	return true, nil
}