seed.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 provider

import (
	"context"
	"fmt"

	kubermaticv1 "k8c.io/kubermatic/v2/pkg/apis/kubermatic/v1"
	"k8c.io/kubermatic/v2/pkg/util/restmapper"

	corev1 "k8s.io/api/core/v1"
	kerrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	ctrlruntimeclient "sigs.k8s.io/controller-runtime/pkg/client"
)

const (
	// DefaultSeedName is the name of the Seed resource that is used
	// in the Community Edition, which is limited to a single seed.
	DefaultSeedName = "kubermatic"
)

var (
	// emptySeedMap is returned when the default seed is not present.
	emptySeedMap = map[string]*kubermaticv1.Seed{}
)

// SeedGetter is a function to retrieve a single seed.
type SeedGetter = func() (*kubermaticv1.Seed, error)

// SeedsGetter is a function to retrieve a list of seeds.
type SeedsGetter = func() (map[string]*kubermaticv1.Seed, error)

// SeedKubeconfigGetter is used to fetch the kubeconfig for a given seed.
type SeedKubeconfigGetter = func(seed *kubermaticv1.Seed) (*rest.Config, error)

// SeedClientGetter is used to get a ctrlruntimeclient for a given seed.
type SeedClientGetter = func(seed *kubermaticv1.Seed) (ctrlruntimeclient.Client, error)

// ClusterProviderGetter is used to get a clusterProvider.
type ClusterProviderGetter = func(seed *kubermaticv1.Seed) (ClusterProvider, error)

// AddonProviderGetter is used to get an AddonProvider.
type AddonProviderGetter = func(seed *kubermaticv1.Seed) (AddonProvider, error)

// ConstraintProviderGetter is used to get a ConstraintProvider.
type ConstraintProviderGetter = func(seed *kubermaticv1.Seed) (ConstraintProvider, error)

// AlertmanagerProviderGetter is used to get an AlertmanagerProvider.
type AlertmanagerProviderGetter = func(seed *kubermaticv1.Seed) (AlertmanagerProvider, error)

// RuleGroupProviderGetter is used to get an RuleGroupProvider.
type RuleGroupProviderGetter = func(seed *kubermaticv1.Seed) (RuleGroupProvider, error)

// PrivilegedMLAAdminSettingProviderGetter is used to get a PrivilegedMLAAdminSettingProvider.
type PrivilegedMLAAdminSettingProviderGetter = func(seed *kubermaticv1.Seed) (PrivilegedMLAAdminSettingProvider, error)

// ClusterTemplateInstanceProviderGetter is used to get a ClusterTemplateInstanceProvider.
type ClusterTemplateInstanceProviderGetter = func(seed *kubermaticv1.Seed) (ClusterTemplateInstanceProvider, error)

// EtcdBackupConfigProviderGetter is used to get a EtcdBackupConfigProvider.
type EtcdBackupConfigProviderGetter = func(seed *kubermaticv1.Seed) (EtcdBackupConfigProvider, error)

// EtcdBackupConfigProjectProviderGetter is used to get a EtcdBackupConfigProjectProvider.
type EtcdBackupConfigProjectProviderGetter = func(seeds map[string]*kubermaticv1.Seed) (EtcdBackupConfigProjectProvider, error)

// EtcdRestoreProviderGetter is used to get a EtcdRestoreProvider.
type EtcdRestoreProviderGetter = func(seed *kubermaticv1.Seed) (EtcdRestoreProvider, error)

// EtcdRestoreProjectProviderGetter is used to get a EtcdRestoreProjectProvider.
type EtcdRestoreProjectProviderGetter = func(seeds map[string]*kubermaticv1.Seed) (EtcdRestoreProjectProvider, error)

// BackupCredentialsProviderGetter is used to get a BackupCredentialsProvider.
type BackupCredentialsProviderGetter = func(seed *kubermaticv1.Seed) (BackupCredentialsProvider, error)

// SeedGetterFactory returns a SeedGetter. It has validation of all its arguments.
func SeedGetterFactory(ctx context.Context, client ctrlruntimeclient.Reader, seedName string, namespace string) (SeedGetter, error) {
	return func() (*kubermaticv1.Seed, error) {
		seed := &kubermaticv1.Seed{}
		if err := client.Get(ctx, types.NamespacedName{Namespace: namespace, Name: seedName}, seed); err != nil {
			// allow callers to handle this gracefully
			if kerrors.IsNotFound(err) {
				return nil, err
			}

			return nil, fmt.Errorf("failed to get seed %q: %w", seedName, err)
		}

		seed.SetDefaults()

		return seed, nil
	}, nil
}

func SeedsGetterFactory(ctx context.Context, client ctrlruntimeclient.Client, namespace string) (SeedsGetter, error) {
	return func() (map[string]*kubermaticv1.Seed, error) {
		seed := &kubermaticv1.Seed{}
		if err := client.Get(ctx, types.NamespacedName{Namespace: namespace, Name: DefaultSeedName}, seed); err != nil {
			if kerrors.IsNotFound(err) {
				// We should not fail if no seed exists and just return an
				// empty map.
				return emptySeedMap, nil
			}

			return nil, fmt.Errorf("failed to get seed %q: %w", DefaultSeedName, err)
		}

		seed.SetDefaults()

		return map[string]*kubermaticv1.Seed{
			DefaultSeedName: seed,
		}, nil
	}, nil
}

func GetSeedKubeconfigSecret(ctx context.Context, client ctrlruntimeclient.Client, seed *kubermaticv1.Seed) (*corev1.Secret, error) {
	secret := &corev1.Secret{}
	name := types.NamespacedName{
		Namespace: seed.Spec.Kubeconfig.Namespace,
		Name:      seed.Spec.Kubeconfig.Name,
	}
	if name.Namespace == "" {
		name.Namespace = seed.Namespace
	}
	if err := client.Get(ctx, name, secret); err != nil {
		return nil, fmt.Errorf("failed to get kubeconfig secret %q: %w", name.String(), err)
	}

	return secret, nil
}

func GetSeedKubeconfig(ctx context.Context, client ctrlruntimeclient.Client, seed *kubermaticv1.Seed) ([]byte, error) {
	secret, err := GetSeedKubeconfigSecret(ctx, client, seed)
	if err != nil {
		return nil, err
	}

	fieldPath := seed.Spec.Kubeconfig.FieldPath
	if len(fieldPath) == 0 {
		fieldPath = DefaultKubeconfigFieldPath
	}
	if _, exists := secret.Data[fieldPath]; !exists {
		return nil, fmt.Errorf("secret %q has no key %q", secret.Name, fieldPath)
	}

	return secret.Data[fieldPath], nil
}

func SeedKubeconfigGetterFactory(ctx context.Context, client ctrlruntimeclient.Client) (SeedKubeconfigGetter, error) {
	return func(seed *kubermaticv1.Seed) (*rest.Config, error) {
		kubeconfig, err := GetSeedKubeconfig(ctx, client, seed)
		if err != nil {
			return nil, err
		}

		cfg, err := clientcmd.RESTConfigFromKubeConfig(kubeconfig)
		if err != nil {
			return nil, fmt.Errorf("failed to load kubeconfig: %w", err)
		}

		return cfg, nil
	}, nil
}

// SeedClientGetterFactory returns a SeedClientGetter. It uses a RestMapperCache to cache
// the discovery data, which considerably speeds up client creation.
func SeedClientGetterFactory(kubeconfigGetter SeedKubeconfigGetter) SeedClientGetter {
	cache := restmapper.New()
	return func(seed *kubermaticv1.Seed) (ctrlruntimeclient.Client, error) {
		cfg, err := kubeconfigGetter(seed)
		if err != nil {
			return nil, err
		}
		return cache.Client(cfg)
	}
}