appworkload_controller.go

/*
Copyright 2022.

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 (
	"context"

	korifiv1alpha1 "code.cloudfoundry.org/korifi/controllers/api/v1alpha1"
	"code.cloudfoundry.org/korifi/tools/k8s"

	"github.com/go-logr/logr"
	appsv1 "k8s.io/api/apps/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/builder"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	"sigs.k8s.io/controller-runtime/pkg/handler"
	"sigs.k8s.io/controller-runtime/pkg/predicate"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
	"sigs.k8s.io/controller-runtime/pkg/source"
)

const (
	// Environment Variable Names
	EnvPodName              = "POD_NAME"
	EnvCFInstanceIP         = "CF_INSTANCE_IP"
	EnvCFInstanceGUID       = "CF_INSTANCE_GUID"
	EnvCFInstanceInternalIP = "CF_INSTANCE_INTERNAL_IP"
	EnvCFInstanceIndex      = "CF_INSTANCE_INDEX"

	// StatefulSet Keys
	AnnotationVersion     = "korifi.cloudfoundry.org/version"
	AnnotationAppID       = "korifi.cloudfoundry.org/application-id"
	AnnotationProcessGUID = "korifi.cloudfoundry.org/process-guid"

	LabelGUID                   = "korifi.cloudfoundry.org/guid"
	LabelVersion                = "korifi.cloudfoundry.org/version"
	LabelAppGUID                = "korifi.cloudfoundry.org/app-guid"
	LabelAppWorkloadGUID        = "korifi.cloudfoundry.org/appworkload-guid"
	LabelProcessType            = "korifi.cloudfoundry.org/process-type"
	LabelStatefulSetRunnerIndex = "korifi.cloudfoundry.org/add-stsr-index"

	ApplicationContainerName  = "application"
	AppWorkloadReconcilerName = "statefulset-runner"
	ServiceAccountName        = "korifi-app"

	LivenessFailureThreshold  = 4
	ReadinessFailureThreshold = 1

	PodAffinityTermWeight = 100
)

//go:generate go run github.com/maxbrunsfeld/counterfeiter/v6 -generate
//counterfeiter:generate -o ../fake -fake-name PDB . PDB
type PDB interface {
	Update(ctx context.Context, statefulSet *appsv1.StatefulSet) error
}

//counterfeiter:generate -o ../fake -fake-name WorkloadToStatefulsetConverter . WorkloadToStatefulsetConverter
type WorkloadToStatefulsetConverter interface {
	Convert(appWorkload *korifiv1alpha1.AppWorkload) (*appsv1.StatefulSet, error)
}

// AppWorkloadReconciler reconciles a AppWorkload object
type AppWorkloadReconciler struct {
	k8sClient        client.Client
	scheme           *runtime.Scheme
	workloadsToStSet WorkloadToStatefulsetConverter
	pdb              PDB
	log              logr.Logger
}

func NewAppWorkloadReconciler(
	c client.Client,
	scheme *runtime.Scheme,
	workloadsToStSet WorkloadToStatefulsetConverter,
	pdb PDB,
	log logr.Logger,
) *k8s.PatchingReconciler[korifiv1alpha1.AppWorkload, *korifiv1alpha1.AppWorkload] {
	appWorkloadReconciler := AppWorkloadReconciler{
		k8sClient:        c,
		scheme:           scheme,
		workloadsToStSet: workloadsToStSet,
		pdb:              pdb,
		log:              log,
	}
	return k8s.NewPatchingReconciler[korifiv1alpha1.AppWorkload, *korifiv1alpha1.AppWorkload](log, c, &appWorkloadReconciler)
}

//+kubebuilder:rbac:groups=korifi.cloudfoundry.org,resources=appworkloads,verbs=get;list;watch;create;patch;delete
//+kubebuilder:rbac:groups=korifi.cloudfoundry.org,resources=appworkloads/status,verbs=get;patch
//+kubebuilder:rbac:groups=apps,resources=statefulsets,verbs=create;patch;get;list;watch
//+kubebuilder:rbac:groups=policy,resources=poddisruptionbudgets,verbs=create;patch;deletecollection

func (r *AppWorkloadReconciler) ReconcileResource(ctx context.Context, appWorkload *korifiv1alpha1.AppWorkload) (ctrl.Result, error) {
	if appWorkload.Spec.RunnerName != AppWorkloadReconcilerName {
		return ctrl.Result{}, nil
	}

	statefulSet, err := r.workloadsToStSet.Convert(appWorkload)
	// Not clear what errors this would produce, but we may use it later
	if err != nil {
		r.log.Info("error when converting AppWorkload", "reason", err)
		return ctrl.Result{}, err
	}

	orig := &appsv1.StatefulSet{
		ObjectMeta: metav1.ObjectMeta{
			Name:      statefulSet.Name,
			Namespace: statefulSet.Namespace,
		},
	}
	_, err = controllerutil.CreateOrPatch(ctx, r.k8sClient, orig, func() error {
		orig.Labels = statefulSet.Labels
		orig.Annotations = statefulSet.Annotations
		orig.OwnerReferences = statefulSet.OwnerReferences
		orig.Spec = statefulSet.Spec

		return nil
	})
	if err != nil {
		r.log.Info("error when creating or updating StatefulSet", "reason", err)
		return ctrl.Result{}, err
	}

	updatedStatefulSet := &appsv1.StatefulSet{}
	err = r.k8sClient.Get(ctx, client.ObjectKeyFromObject(statefulSet), updatedStatefulSet)
	if err != nil {
		if apierrors.IsNotFound(err) {
			return ctrl.Result{}, nil
		} else {
			r.log.Info("error when fetching StatefulSet", "StatefulSet.Name", statefulSet.Name, "StatefulSet.Namespace", statefulSet.Namespace, "reason", err)
			return ctrl.Result{}, err
		}
	}

	err = r.pdb.Update(ctx, updatedStatefulSet)
	if err != nil {
		r.log.Info("error when creating or patching pod disruption budget", "reason", err)
		return ctrl.Result{}, err
	}

	return ctrl.Result{}, nil
}

func (r *AppWorkloadReconciler) SetupWithManager(mgr ctrl.Manager) *builder.Builder {
	return ctrl.NewControllerManagedBy(mgr).
		For(&korifiv1alpha1.AppWorkload{}).
		Watches(
			&source.Kind{Type: new(appsv1.StatefulSet)},
			handler.EnqueueRequestsFromMapFunc(func(obj client.Object) []reconcile.Request {
				var requests []reconcile.Request
				if appWorkloadName, ok := obj.GetLabels()[LabelAppWorkloadGUID]; ok {
					requests = append(requests, reconcile.Request{
						NamespacedName: types.NamespacedName{
							Name:      appWorkloadName,
							Namespace: obj.GetNamespace(),
						},
					})
				}
				return requests
			})).
		WithEventFilter(predicate.NewPredicateFuncs(filterAppWorkloads))
}

func filterAppWorkloads(object client.Object) bool {
	appWorkload, ok := object.(*korifiv1alpha1.AppWorkload)
	if !ok {
		return true
	}

	return appWorkload.Spec.RunnerName == AppWorkloadReconcilerName
}