trainer/pkg/webhooks/trainingruntime_webhook.go

/*
Copyright 2024 The Kubeflow 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 webhooks

import (
	"context"
	"fmt"

	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/apimachinery/pkg/util/validation/field"
	"k8s.io/klog/v2"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
	jobsetv1alpha2 "sigs.k8s.io/jobset/api/jobset/v1alpha2"

	trainer "github.com/kubeflow/trainer/v2/pkg/apis/trainer/v1alpha1"
	"github.com/kubeflow/trainer/v2/pkg/constants"
)

const (
	rJobReplicasErrorMsg       = "always must be 1"
	rJobContainerNamesErrorMsg = "must contain the required container for the ancestor: %s"
)

var (
	expectedContainerNames = map[string]string{
		constants.AncestorTrainer:    constants.Node,
		constants.ModelInitializer:   constants.ModelInitializer,
		constants.DatasetInitializer: constants.DatasetInitializer,
	}
)

// +kubebuilder:webhook:path=/validate-trainer-kubeflow-org-v1alpha1-trainingruntime,mutating=false,failurePolicy=fail,sideEffects=None,groups=trainer.kubeflow.org,resources=trainingruntimes,verbs=create;update,versions=v1alpha1,name=validator.trainingruntime.trainer.kubeflow.org,admissionReviewVersions=v1

// TrainingRuntimeValidator validates TrainingRuntimes
type TrainingRuntimeValidator struct{}

var _ admission.Validator[*trainer.TrainingRuntime] = (*TrainingRuntimeValidator)(nil)

func setupWebhookForTrainingRuntime(mgr ctrl.Manager) error {
	return ctrl.NewWebhookManagedBy(mgr, &trainer.TrainingRuntime{}).
		WithValidator(&TrainingRuntimeValidator{}).
		Complete()
}

func (w *TrainingRuntimeValidator) ValidateCreate(ctx context.Context, obj *trainer.TrainingRuntime) (admission.Warnings, error) {
	log := ctrl.LoggerFrom(ctx).WithName("trainingruntime-webhook")
	log.V(5).Info("Validating create", "trainingRuntime", klog.KObj(obj))
	return nil, validateReplicatedJobs(obj.Spec.Template.Spec.ReplicatedJobs).ToAggregate()
}

func validateReplicatedJobs(rJobs []jobsetv1alpha2.ReplicatedJob) field.ErrorList {
	ancestors := sets.New(constants.AncestorTrainer, constants.ModelInitializer, constants.DatasetInitializer)
	rJobsPath := field.NewPath("spec").
		Child("template").
		Child("spec").
		Child("replicatedJobs")
	var allErrs field.ErrorList
	for idx, rJob := range rJobs {
		if rJob.Template.Labels == nil {
			continue
		}

		if labelAncestor, ok := rJob.Template.Labels[constants.LabelTrainJobAncestor]; ok && ancestors.Has(labelAncestor) {
			if rJob.Replicas != 1 {
				allErrs = append(allErrs, field.Invalid(rJobsPath.Index(idx).Child("replicas"), rJob.Replicas, rJobReplicasErrorMsg))
			}

			// Validate replicated job contains the required containers.
			// Mapping of the ancestor labels to the containers:
			// 1. dataset-initializer - dataset-initializer
			// 2. model-initializer - model-initializer
			// 3. trainer - node
			hasRequiredContainer := false
			for _, container := range rJob.Template.Spec.Template.Spec.Containers {
				if container.Name == expectedContainerNames[labelAncestor] {
					hasRequiredContainer = true
					break
				}
			}
			if !hasRequiredContainer {
				allErrs = append(allErrs, field.Invalid(
					rJobsPath.Index(idx).Child("template").Child("spec").Child("template").Child("spec").Child("containers"),
					rJob.Template.Spec.Template.Spec.Containers,
					fmt.Sprintf(rJobContainerNamesErrorMsg, labelAncestor),
				))
			}
		}
	}
	return allErrs
}

func (w *TrainingRuntimeValidator) ValidateUpdate(ctx context.Context, oldObj, newObj *trainer.TrainingRuntime) (admission.Warnings, error) {
	return nil, nil
}

func (w *TrainingRuntimeValidator) ValidateDelete(ctx context.Context, obj *trainer.TrainingRuntime) (admission.Warnings, error) {
	return nil, nil
}