image_webhook.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 v1

import (
	"context"
	"errors"
	"fmt"
	"os"
	"strings"

	"github.com/go-logr/logr"
	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
)

// log is for logging in this package.
var imagelog = logf.Log.WithName("image-resource")

func (i *Image) SetupWebhookWithManager(mgr ctrl.Manager) error {
	m := &ImageMutator{Client: mgr.GetClient()}
	v := &ImageValidator{Client: mgr.GetClient()}
	return ctrl.NewWebhookManagedBy(mgr).
		For(i).
		WithDefaulter(m).
		WithValidator(v).
		Complete()
}

//+kubebuilder:webhook:path=/mutate-imagehub-sealos-io-v1-image,mutating=true,failurePolicy=fail,sideEffects=None,groups=imagehub.sealos.io,resources=images,verbs=create;update,versions=v1,name=mimage.kb.io,admissionReviewVersions=v1
//+kubebuilder:object:generate=false

type ImageMutator struct {
	client.Client
}

func (m *ImageMutator) Default(ctx context.Context, obj runtime.Object) error {
	img, ok := obj.(*Image)
	if !ok {
		return errors.New("obj convert Image is error")
	}
	imagelog.Info("default", "name", img.Name)
	img.ObjectMeta = initAnnotationAndLabels(img.ObjectMeta)
	img.ObjectMeta.Labels[SealosOrgLable] = img.Spec.Name.GetOrg()
	img.ObjectMeta.Labels[SealosRepoLabel] = img.Spec.Name.GetRepo()
	img.ObjectMeta.Labels[SealosTagLabel] = img.Spec.Name.GetTag()

	oldimg := &Image{}
	oldimg.Name = img.Name
	err := m.Get(ctx, client.ObjectKeyFromObject(oldimg), oldimg)
	if err != nil {
		return client.IgnoreNotFound(err)
	}
	// mulate image cr
	img.MulateFromOldobj(oldimg)
	return nil
}

//+kubebuilder:webhook:path=/validate-imagehub-sealos-io-v1-image,mutating=false,failurePolicy=fail,sideEffects=None,groups=imagehub.sealos.io,resources=images,verbs=create;update;delete,versions=v1,name=vimage.kb.io,admissionReviewVersions=v1
//+kubebuilder:object:generate=false

// ImageValidator will validate Images change.
type ImageValidator struct {
	client.Client
}

func (v *ImageValidator) ValidateCreate(ctx context.Context, obj runtime.Object) error {
	i, ok := obj.(*Image)
	if !ok {
		return errors.New("obj convert Image is error")
	}
	imagelog.Info("validating create", "name", i.Name)
	imagelog.Info("enter checkOption func", "name", i.Name)
	return checkOption(ctx, imagelog, v.Client, i)
}

func (v *ImageValidator) ValidateUpdate(ctx context.Context, oldObj, newObj runtime.Object) error {
	ni, ok := newObj.(*Image)
	if !ok {
		return errors.New("obj convert Image is error")
	}
	oi, ok := oldObj.(*Image)
	if !ok {
		return errors.New("obj convert Image is error")
	}
	imagelog.Info("validating update", "name", oi.Name)
	if ni.Spec.Name != oi.Spec.Name {
		return fmt.Errorf("can not change spec.name: %s", string(ni.Spec.Name))
	}
	imagelog.Info("enter checkOption func", "name", ni.Name)
	return checkOption(ctx, imagelog, v.Client, ni)
}

func (v *ImageValidator) ValidateDelete(ctx context.Context, obj runtime.Object) error {
	i, ok := obj.(*Image)
	if !ok {
		return errors.New("obj convert Image is error")
	}
	imagelog.Info("validating delete", "name", i.Name)
	imagelog.Info("enter checkOption func", "name", i.Name)
	return checkOption(ctx, imagelog, v.Client, i)
}

// default userSaGroup: system:serviceaccounts:user-system
var imagehubSaGroup, userSaGroup, kubeSystemGroup string

func init() {
	// notice: group is like: system:serviceaccounts:namespace-name
	imagehubSaGroup = fmt.Sprintf("%ss:%s", saPrefix, getImagehubNamespace())
	userSaGroup = fmt.Sprintf("%ss:%s", saPrefix, getUserNamespace())
	kubeSystemGroup = fmt.Sprintf("%ss:%s", saPrefix, kubeSystemNamespace)
}

func checkOption(ctx context.Context, logger logr.Logger, c client.Client, i Checker) error {
	logger.Info("checking label and spec name", "obj name", i.getSpecName())
	if !i.checkLabels() || !i.checkSpecName() {
		return fmt.Errorf("missing labels or obj.Spec.Name is IsLegal: %s", i.getSpecName())
	}

	logger.Info("getting req from ctx")
	req, err := admission.RequestFromContext(ctx)
	if err != nil {
		logger.Info("get request from context error when validate", "obj name", i.getName())
		return err
	}
	logger.Info("checking user", "user", req.UserInfo.Username)
	// get userName by replace "system:serviceaccount:user-system:labring-user-name" to "labring-user-name"
	userName := strings.Replace(req.UserInfo.Username, fmt.Sprintf("%s:%s:", saPrefix, getUserNamespace()), "", -1)

	for _, g := range req.UserInfo.Groups {
		switch g {
		// if user is kubernetes-admin, pass it.
		case mastersGroup:
			logger.Info("pass for kubernetes-admin")
			return nil
		case kubeSystemGroup:
			logger.Info("pass for kube-system")
			return nil
		case imagehubSaGroup:
			logger.Info("pass for imagehub controller service account")
			return nil
		case userSaGroup:
			logger.Info("checking username", "user", userName)
			managers, err := getOrgManagers(ctx, c, i)
			if err != nil {
				logger.Info("get org managers error", "org name", i.getOrgName())
				return err
			}
			for _, manager := range managers {
				if userName == manager {
					logger.Info("passed for user", "user name", userName)
					return nil
				}
			}
			// continue to check other groups
			continue
		default:
			// continue to check other groups
			continue
		}
	}
	logger.Info("denied", "obj name", i.getName())
	return fmt.Errorf("denied, you are not one of organization %s managers", i.getOrgName())
}

func getUserNamespace() string {
	userNamespace := os.Getenv("USER_NAMESPACE")
	if userNamespace == "" {
		return defaultUserNamespace
	}
	return userNamespace
}
func getImagehubNamespace() string {
	imagehubNamespace := os.Getenv("IMAGEHUB_NAMESPACE")
	if imagehubNamespace == "" {
		return defaultImagehubNamespace
	}
	return imagehubNamespace
}

func getOrgManagers(ctx context.Context, c client.Client, i Checker) (res []string, err error) {
	org := &Organization{}
	if err = c.Get(ctx, client.ObjectKey{Name: i.getOrgName()}, org); err != nil {
		if client.IgnoreNotFound(err) == nil {
			return
		}
		err = fmt.Errorf("get Organization error %s", i.getOrgName())
		return
	}
	res = org.Spec.Manager
	return
}