ContainerImage.Pinniped/internal/controller/supervisorconfig/secretgenerator/secretgenerator.go

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// Copyright 2020 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package secretgenerator provides a controller that can ensure existence of a generated secret.
package secretgenerator
import (
"context"
"crypto/rand"
"fmt"
corev1 "k8s.io/api/core/v1"
k8serrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
corev1informers "k8s.io/client-go/informers/core/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/util/retry"
"k8s.io/klog/v2"
pinnipedcontroller "go.pinniped.dev/internal/controller"
"go.pinniped.dev/internal/controllerlib"
"go.pinniped.dev/internal/plog"
)
const (
symmetricKeySecretType = "secrets.pinniped.dev/symmetric"
symmetricKeySecretDataKey = "key"
symmetricKeySize = 32 // TODO: what should this be?
)
// generateKey is stubbed out for the purpose of testing. The default behavior is to generate a symmetric key.
//nolint:gochecknoglobals
var generateKey = generateSymmetricKey
func generateSymmetricKey() ([]byte, error) {
b := make([]byte, symmetricKeySize)
if _, err := rand.Read(b); err != nil {
return nil, err
}
return b, nil
}
type controller struct {
secretNamePrefix string
client kubernetes.Interface
secrets corev1informers.SecretInformer
}
// New instantiates a new controllerlib.Controller which will ensure existence of a generated secret.
func New(secretNamePrefix string, client kubernetes.Interface, secrets corev1informers.SecretInformer) controllerlib.Controller {
c := controller{
secretNamePrefix: secretNamePrefix,
client: client,
secrets: secrets,
}
filter := pinnipedcontroller.SimpleFilterWithSingletonQueue(isOwnee)
return controllerlib.New(
controllerlib.Config{Name: secretNamePrefix + "-secrets-generator", Syncer: &c},
controllerlib.WithInformer(secrets, filter, controllerlib.InformerOption{}),
)
}
// Sync implements controllerlib.Syncer.Sync().
func (c *controller) Sync(ctx controllerlib.Context) error {
secret, err := c.secrets.Lister().Secrets(ctx.Key.Namespace).Get(ctx.Key.Name)
isNotFound := k8serrors.IsNotFound(err)
if !isNotFound && err != nil {
return fmt.Errorf("failed to list secret %s/%s: %w", ctx.Key.Namespace, ctx.Key.Name, err)
}
secretNeedsUpdate := isNotFound || !c.isValid(secret)
if !secretNeedsUpdate {
plog.Debug("secret is up to date", "secret", klog.KObj(secret))
return nil
}
newSecret, err := c.generateSecret(ctx.Key.Namespace)
if err != nil {
return fmt.Errorf("failed to generate secret: %w", err)
}
if isNotFound {
err = c.createSecret(ctx.Context, newSecret)
} else {
err = c.updateSecret(ctx.Context, newSecret, ctx.Key.Name)
}
if err != nil {
return fmt.Errorf("failed to create/update secret %s/%s: %w", ctx.Key.Namespace, ctx.Key.Name, err)
}
return nil
}
func (c *controller) isValid(secret *corev1.Secret) bool {
if secret.Type != symmetricKeySecretType {
return false
}
data, ok := secret.Data[symmetricKeySecretDataKey]
if !ok {
return false
}
if len(data) != symmetricKeySize {
return false
}
return true
}
func (c *controller) generateSecret(namespace string) (*corev1.Secret, error) {
symmetricKey, err := generateKey()
if err != nil {
return nil, err
}
return &corev1.Secret{
ObjectMeta: metav1.ObjectMeta{
GenerateName: c.secretNamePrefix,
Namespace: namespace,
},
Type: symmetricKeySecretType,
Data: map[string][]byte{
symmetricKeySecretDataKey: symmetricKey,
},
}, nil
}
func (c *controller) createSecret(ctx context.Context, newSecret *corev1.Secret) error {
_, err := c.client.CoreV1().Secrets(newSecret.Namespace).Create(ctx, newSecret, metav1.CreateOptions{})
return err
}
func (c *controller) updateSecret(ctx context.Context, newSecret *corev1.Secret, secretName string) error {
secrets := c.client.CoreV1().Secrets(newSecret.Namespace)
return retry.RetryOnConflict(retry.DefaultBackoff, func() error {
currentSecret, err := secrets.Get(ctx, secretName, metav1.GetOptions{})
isNotFound := k8serrors.IsNotFound(err)
if !isNotFound && err != nil {
return fmt.Errorf("failed to get secret: %w", err)
}
if isNotFound {
if err := c.createSecret(ctx, newSecret); err != nil {
return fmt.Errorf("failed to create secret: %w", err)
}
return nil
}
if c.isValid(currentSecret) {
return nil
}
currentSecret.Type = newSecret.Type
currentSecret.Data = newSecret.Data
_, err = secrets.Update(ctx, currentSecret, metav1.UpdateOptions{})
return err
})
}
// isOwnee returns whether the provided obj is owned by this controller.
func isOwnee(obj metav1.Object) bool {
// TODO: how do we say we are owned by our Deployment?
return true
}