admission_plugin.go

/*
Copyright 2020 The Kubermatic Kubernetes Platform contributors.

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 kubernetes

import (
	"context"
	"fmt"

	"github.com/Masterminds/semver"

	kubermaticv1 "github.com/kubermatic/kubermatic/api/pkg/crd/kubermatic/v1"
	"github.com/kubermatic/kubermatic/api/pkg/provider"

	kerrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime/schema"
	ctrlruntimeclient "sigs.k8s.io/controller-runtime/pkg/client"
)

// admissionPluginsGetter is a function to retrieve admission plugins
type admissionPluginsGetter = func() ([]kubermaticv1.AdmissionPlugin, error)

// AdmissionPluginsProvider is a object to handle admission plugins
type AdmissionPluginsProvider struct {
	admissionPluginsGetter admissionPluginsGetter
	client                 ctrlruntimeclient.Client
	ctx                    context.Context
}

func NewAdmissionPluginsProvider(ctx context.Context, client ctrlruntimeclient.Client) *AdmissionPluginsProvider {
	admissionPluginsGetter := func() ([]kubermaticv1.AdmissionPlugin, error) {
		admissionPluginList := &kubermaticv1.AdmissionPluginList{}
		if err := client.List(ctx, admissionPluginList); err != nil {
			return nil, fmt.Errorf("failed to get admission plugins %v", err)
		}
		return admissionPluginList.Items, nil
	}

	return &AdmissionPluginsProvider{admissionPluginsGetter: admissionPluginsGetter, client: client, ctx: ctx}
}

func (p *AdmissionPluginsProvider) ListPluginNamesFromVersion(fromVersion string) ([]string, error) {
	if fromVersion == "" {
		return nil, fmt.Errorf("fromVersion can not be empty")
	}
	admissionPluginList, err := p.admissionPluginsGetter()
	if err != nil {
		return nil, err
	}

	plugins := []string{}
	v, err := semver.NewVersion(fromVersion)
	if err != nil {
		return nil, err
	}
	for _, plugin := range admissionPluginList {
		// all without version constrain
		if plugin.Spec.FromVersion == nil {
			plugins = append(plugins, plugin.Spec.PluginName)
			continue
		}
		// version >= plugin.version
		if v.Equal(plugin.Spec.FromVersion.Version) || v.GreaterThan(plugin.Spec.FromVersion.Version) {
			plugins = append(plugins, plugin.Spec.PluginName)
		}
	}
	return plugins, nil

}

func (p *AdmissionPluginsProvider) List(userInfo *provider.UserInfo) ([]kubermaticv1.AdmissionPlugin, error) {
	if !userInfo.IsAdmin {
		return nil, kerrors.NewForbidden(schema.GroupResource{}, userInfo.Email, fmt.Errorf("%q doesn't have admin rights", userInfo.Email))
	}
	admissionPluginList, err := p.admissionPluginsGetter()
	if err != nil {
		return nil, err
	}
	return admissionPluginList, nil
}

func (p *AdmissionPluginsProvider) Get(userInfo *provider.UserInfo, name string) (*kubermaticv1.AdmissionPlugin, error) {
	if !userInfo.IsAdmin {
		return nil, kerrors.NewForbidden(schema.GroupResource{}, userInfo.Email, fmt.Errorf("%q doesn't have admin rights", userInfo.Email))
	}
	admissionPluginList, err := p.admissionPluginsGetter()
	if err != nil {
		return nil, err
	}
	for _, plugin := range admissionPluginList {
		if plugin.Name == name {
			return &plugin, nil
		}
	}
	return nil, kerrors.NewNotFound(schema.GroupResource{}, name)
}

func (p *AdmissionPluginsProvider) Delete(userInfo *provider.UserInfo, name string) error {

	plugin, err := p.Get(userInfo, name)
	if err != nil {
		return err
	}
	if err := p.client.Delete(p.ctx, plugin); err != nil {
		return fmt.Errorf("failed to delete admission plugins %v", err)
	}
	return nil
}

func (p *AdmissionPluginsProvider) Update(userInfo *provider.UserInfo, admissionPlugin *kubermaticv1.AdmissionPlugin) (*kubermaticv1.AdmissionPlugin, error) {
	if admissionPlugin == nil {
		return nil, fmt.Errorf("the admissionPlugin can not be nil")
	}

	oldAdmissionPlugin, err := p.Get(userInfo, admissionPlugin.Name)
	if err != nil {
		return nil, err
	}
	if err := p.client.Patch(p.ctx, admissionPlugin, ctrlruntimeclient.MergeFrom(oldAdmissionPlugin)); err != nil {
		return nil, fmt.Errorf("failed to update AdmissionPlugin: %v", err)
	}

	return admissionPlugin, nil
}