sigs.k8s.io/cluster-api-provider-azure@v1.17.0/exp/api/v1beta1/azuremachinepool_webhook.go

/*
Copyright 2021 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 v1beta1

import (
	"context"
	"fmt"
	"reflect"

	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/compute/armcompute/v5"
	"github.com/blang/semver"
	"github.com/pkg/errors"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	kerrors "k8s.io/apimachinery/pkg/util/errors"
	"k8s.io/apimachinery/pkg/util/intstr"
	"k8s.io/apimachinery/pkg/util/validation/field"
	infrav1 "sigs.k8s.io/cluster-api-provider-azure/api/v1beta1"
	"sigs.k8s.io/cluster-api-provider-azure/feature"
	azureutil "sigs.k8s.io/cluster-api-provider-azure/util/azure"
	capifeature "sigs.k8s.io/cluster-api/feature"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
)

// SetupAzureMachinePoolWebhookWithManager sets up and registers the webhook with the manager.
func SetupAzureMachinePoolWebhookWithManager(mgr ctrl.Manager) error {
	ampw := &azureMachinePoolWebhook{Client: mgr.GetClient()}
	return ctrl.NewWebhookManagedBy(mgr).
		For(&AzureMachinePool{}).
		WithDefaulter(ampw).
		WithValidator(ampw).
		Complete()
}

// +kubebuilder:webhook:path=/mutate-infrastructure-cluster-x-k8s-io-v1beta1-azuremachinepool,mutating=true,failurePolicy=fail,groups=infrastructure.cluster.x-k8s.io,resources=azuremachinepools,verbs=create;update,versions=v1beta1,name=default.azuremachinepool.infrastructure.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1

// azureMachinePoolWebhook implements a validating and defaulting webhook for AzureMachinePool.
type azureMachinePoolWebhook struct {
	Client client.Client
}

// Default implements webhook.Defaulter so a webhook will be registered for the type.
func (ampw *azureMachinePoolWebhook) Default(ctx context.Context, obj runtime.Object) error {
	amp, ok := obj.(*AzureMachinePool)
	if !ok {
		return apierrors.NewBadRequest("expected an AzureMachinePool")
	}
	return amp.SetDefaults(ampw.Client)
}

// +kubebuilder:webhook:verbs=create;update,path=/validate-infrastructure-cluster-x-k8s-io-v1beta1-azuremachinepool,mutating=false,failurePolicy=fail,groups=infrastructure.cluster.x-k8s.io,resources=azuremachinepools,versions=v1beta1,name=validation.azuremachinepool.infrastructure.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1

// ValidateCreate implements webhook.Validator so a webhook will be registered for the type.
func (ampw *azureMachinePoolWebhook) ValidateCreate(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
	amp, ok := obj.(*AzureMachinePool)
	if !ok {
		return nil, apierrors.NewBadRequest("expected an AzureMachinePool")
	}
	// NOTE: AzureMachinePool is behind MachinePool feature gate flag; the webhook
	// must prevent creating new objects in case the feature flag is disabled.
	if !feature.Gates.Enabled(capifeature.MachinePool) {
		return nil, field.Forbidden(
			field.NewPath("spec"),
			"can be set only if the MachinePool feature flag is enabled",
		)
	}
	return nil, amp.Validate(nil, ampw.Client)
}

// ValidateUpdate implements webhook.Validator so a webhook will be registered for the type.
func (ampw *azureMachinePoolWebhook) ValidateUpdate(ctx context.Context, oldObj, newObj runtime.Object) (admission.Warnings, error) {
	amp, ok := newObj.(*AzureMachinePool)
	if !ok {
		return nil, apierrors.NewBadRequest("expected an AzureMachinePool")
	}
	return nil, amp.Validate(oldObj, ampw.Client)
}

// ValidateDelete implements webhook.Validator so a webhook will be registered for the type.
func (ampw *azureMachinePoolWebhook) ValidateDelete(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
	return nil, nil
}

// Validate the Azure Machine Pool and return an aggregate error.
func (amp *AzureMachinePool) Validate(old runtime.Object, client client.Client) error {
	validators := []func() error{
		amp.ValidateImage,
		amp.ValidateTerminateNotificationTimeout,
		amp.ValidateSSHKey,
		amp.ValidateUserAssignedIdentity,
		amp.ValidateDiagnostics,
		amp.ValidateOrchestrationMode(client),
		amp.ValidateStrategy(),
		amp.ValidateSystemAssignedIdentity(old),
		amp.ValidateSystemAssignedIdentityRole,
		amp.ValidateNetwork,
		amp.ValidateOSDisk,
	}

	var errs []error
	for _, validator := range validators {
		if err := validator(); err != nil {
			errs = append(errs, err)
		}
	}

	return kerrors.NewAggregate(errs)
}

// ValidateNetwork of an AzureMachinePool.
func (amp *AzureMachinePool) ValidateNetwork() error {
	if (amp.Spec.Template.NetworkInterfaces != nil) && len(amp.Spec.Template.NetworkInterfaces) > 0 && amp.Spec.Template.SubnetName != "" {
		return errors.New("cannot set both NetworkInterfaces and machine SubnetName")
	}
	return nil
}

// ValidateOSDisk of an AzureMachinePool.
func (amp *AzureMachinePool) ValidateOSDisk() error {
	if errs := infrav1.ValidateOSDisk(amp.Spec.Template.OSDisk, field.NewPath("osDisk")); len(errs) > 0 {
		return errs.ToAggregate()
	}
	return nil
}

// ValidateImage of an AzureMachinePool.
func (amp *AzureMachinePool) ValidateImage() error {
	if amp.Spec.Template.Image != nil {
		image := amp.Spec.Template.Image
		if errs := infrav1.ValidateImage(image, field.NewPath("image")); len(errs) > 0 {
			return errs.ToAggregate()
		}
	}

	return nil
}

// ValidateTerminateNotificationTimeout termination notification timeout to be between 5 and 15.
func (amp *AzureMachinePool) ValidateTerminateNotificationTimeout() error {
	if amp.Spec.Template.TerminateNotificationTimeout == nil {
		return nil
	}
	if *amp.Spec.Template.TerminateNotificationTimeout < 5 {
		return errors.New("minimum timeout 5 is allowed for TerminateNotificationTimeout")
	}

	if *amp.Spec.Template.TerminateNotificationTimeout > 15 {
		return errors.New("maximum timeout 15 is allowed for TerminateNotificationTimeout")
	}

	return nil
}

// ValidateSSHKey validates an SSHKey.
func (amp *AzureMachinePool) ValidateSSHKey() error {
	if amp.Spec.Template.SSHPublicKey != "" {
		sshKey := amp.Spec.Template.SSHPublicKey
		if errs := infrav1.ValidateSSHKey(sshKey, field.NewPath("sshKey")); len(errs) > 0 {
			agg := kerrors.NewAggregate(errs.ToAggregate().Errors())
			return agg
		}
	}

	return nil
}

// ValidateUserAssignedIdentity validates the user-assigned identities list.
func (amp *AzureMachinePool) ValidateUserAssignedIdentity() error {
	fldPath := field.NewPath("userAssignedIdentities")
	if errs := infrav1.ValidateUserAssignedIdentity(amp.Spec.Identity, amp.Spec.UserAssignedIdentities, fldPath); len(errs) > 0 {
		return kerrors.NewAggregate(errs.ToAggregate().Errors())
	}

	return nil
}

// ValidateStrategy validates the strategy.
func (amp *AzureMachinePool) ValidateStrategy() func() error {
	return func() error {
		if amp.Spec.Strategy.Type == RollingUpdateAzureMachinePoolDeploymentStrategyType && amp.Spec.Strategy.RollingUpdate != nil {
			rollingUpdateStrategy := amp.Spec.Strategy.RollingUpdate
			maxSurge := rollingUpdateStrategy.MaxSurge
			maxUnavailable := rollingUpdateStrategy.MaxUnavailable
			if maxSurge.Type == intstr.Int && maxSurge.IntVal == 0 &&
				maxUnavailable.Type == intstr.Int && maxUnavailable.IntVal == 0 {
				return errors.New("rolling update strategy MaxUnavailable must not be 0 if MaxSurge is 0")
			}
		}

		return nil
	}
}

// ValidateSystemAssignedIdentity validates system-assigned identity role.
func (amp *AzureMachinePool) ValidateSystemAssignedIdentity(old runtime.Object) func() error {
	return func() error {
		var oldRole string
		if old != nil {
			oldMachinePool, ok := old.(*AzureMachinePool)
			if !ok {
				return fmt.Errorf("unexpected type for old azure machine pool object. Expected: %q, Got: %q",
					"AzureMachinePool", reflect.TypeOf(old))
			}
			if amp.Spec.SystemAssignedIdentityRole != nil {
				oldRole = oldMachinePool.Spec.SystemAssignedIdentityRole.Name
			}
		}

		roleAssignmentName := ""
		if amp.Spec.SystemAssignedIdentityRole != nil {
			roleAssignmentName = amp.Spec.SystemAssignedIdentityRole.Name
		}

		fldPath := field.NewPath("roleAssignmentName")
		if errs := infrav1.ValidateSystemAssignedIdentity(amp.Spec.Identity, oldRole, roleAssignmentName, fldPath); len(errs) > 0 {
			return kerrors.NewAggregate(errs.ToAggregate().Errors())
		}

		return nil
	}
}

// ValidateSystemAssignedIdentityRole validates the scope and roleDefinitionID for the system-assigned identity.
func (amp *AzureMachinePool) ValidateSystemAssignedIdentityRole() error {
	var allErrs field.ErrorList
	if amp.Spec.RoleAssignmentName != "" && amp.Spec.SystemAssignedIdentityRole != nil && amp.Spec.SystemAssignedIdentityRole.Name != "" {
		allErrs = append(allErrs, field.Invalid(field.NewPath("systemAssignedIdentityRole"), amp.Spec.SystemAssignedIdentityRole.Name, "cannot set both roleAssignmentName and systemAssignedIdentityRole.name"))
	}
	if amp.Spec.Identity == infrav1.VMIdentitySystemAssigned {
		if amp.Spec.SystemAssignedIdentityRole.DefinitionID == "" {
			allErrs = append(allErrs, field.Invalid(field.NewPath("systemAssignedIdentityRole", "definitionID"), amp.Spec.SystemAssignedIdentityRole.DefinitionID, "the roleDefinitionID field cannot be empty"))
		}
		if amp.Spec.SystemAssignedIdentityRole.Scope == "" {
			allErrs = append(allErrs, field.Invalid(field.NewPath("systemAssignedIdentityRole", "scope"), amp.Spec.SystemAssignedIdentityRole.Scope, "the scope field cannot be empty"))
		}
	}
	if amp.Spec.Identity != infrav1.VMIdentitySystemAssigned && amp.Spec.SystemAssignedIdentityRole != nil {
		allErrs = append(allErrs, field.Invalid(field.NewPath("systemAssignedIdentityRole"), amp.Spec.SystemAssignedIdentityRole, "systemAssignedIdentityRole can only be set when identity is set to 'SystemAssigned'"))
	}

	if len(allErrs) > 0 {
		return kerrors.NewAggregate(allErrs.ToAggregate().Errors())
	}

	return nil
}

// ValidateDiagnostics validates the Diagnostic spec.
func (amp *AzureMachinePool) ValidateDiagnostics() error {
	var allErrs field.ErrorList
	fieldPath := field.NewPath("diagnostics")

	diagnostics := amp.Spec.Template.Diagnostics

	if diagnostics != nil && diagnostics.Boot != nil {
		switch diagnostics.Boot.StorageAccountType {
		case infrav1.UserManagedDiagnosticsStorage:
			if diagnostics.Boot.UserManaged == nil {
				allErrs = append(allErrs, field.Required(fieldPath.Child("UserManaged"),
					fmt.Sprintf("userManaged must be specified when storageAccountType is '%s'", infrav1.UserManagedDiagnosticsStorage)))
			} else if diagnostics.Boot.UserManaged.StorageAccountURI == "" {
				allErrs = append(allErrs, field.Required(fieldPath.Child("StorageAccountURI"),
					fmt.Sprintf("StorageAccountURI cannot be empty when storageAccountType is '%s'", infrav1.UserManagedDiagnosticsStorage)))
			}
		case infrav1.ManagedDiagnosticsStorage:
			if diagnostics.Boot.UserManaged != nil &&
				diagnostics.Boot.UserManaged.StorageAccountURI != "" {
				allErrs = append(allErrs, field.Invalid(fieldPath.Child("StorageAccountURI"), diagnostics.Boot.UserManaged.StorageAccountURI,
					fmt.Sprintf("StorageAccountURI cannot be set when storageAccountType is '%s'",
						infrav1.ManagedDiagnosticsStorage)))
			}
		case infrav1.DisabledDiagnosticsStorage:
			if diagnostics.Boot.UserManaged != nil &&
				diagnostics.Boot.UserManaged.StorageAccountURI != "" {
				allErrs = append(allErrs, field.Invalid(fieldPath.Child("StorageAccountURI"), diagnostics.Boot.UserManaged.StorageAccountURI,
					fmt.Sprintf("StorageAccountURI cannot be set when storageAccountType is '%s'",
						infrav1.ManagedDiagnosticsStorage)))
			}
		}
	}

	if len(allErrs) > 0 {
		return kerrors.NewAggregate(allErrs.ToAggregate().Errors())
	}

	return nil
}

// ValidateOrchestrationMode validates requirements for the VMSS orchestration mode.
func (amp *AzureMachinePool) ValidateOrchestrationMode(c client.Client) func() error {
	return func() error {
		// Only Flexible orchestration mode requires validation.
		if amp.Spec.OrchestrationMode == infrav1.OrchestrationModeType(armcompute.OrchestrationModeFlexible) {
			parent, err := azureutil.FindParentMachinePoolWithRetry(amp.Name, c, 5)
			if err != nil {
				return errors.Wrap(err, "failed to find parent MachinePool")
			}
			// Kubernetes must be >= 1.26.0 for cloud-provider-azure Helm chart support.
			if parent.Spec.Template.Spec.Version == nil {
				return errors.New("could not find Kubernetes version in MachinePool")
			}
			k8sVersion, err := semver.ParseTolerant(*parent.Spec.Template.Spec.Version)
			if err != nil {
				return errors.Wrap(err, "failed to parse Kubernetes version")
			}
			if k8sVersion.LT(semver.MustParse("1.26.0")) {
				return errors.New(fmt.Sprintf("specified Kubernetes version %s must be >= 1.26.0 for Flexible orchestration mode", k8sVersion))
			}
		}

		return nil
	}
}