k3s/pkg/cluster/storage.go
Vitor Savian 5d69d6e782 Add tls for kine
Signed-off-by: Vitor Savian <vitor.savian@suse.com>

Bump kine

Signed-off-by: Vitor Savian <vitor.savian@suse.com>

Add integration tests for kine with tls

Signed-off-by: Vitor Savian <vitor.savian@suse.com>
2024-03-28 11:12:07 -03:00

360 lines
12 KiB
Go

package cluster
import (
"bytes"
"context"
"errors"
"time"
"github.com/k3s-io/k3s/pkg/bootstrap"
"github.com/k3s-io/k3s/pkg/daemons/config"
"github.com/k3s-io/k3s/pkg/util"
"github.com/k3s-io/kine/pkg/client"
"github.com/sirupsen/logrus"
"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
"k8s.io/apimachinery/pkg/util/wait"
)
// maxBootstrapWaitAttempts is the number of iterations to wait for another node to populate an empty bootstrap key.
// After this many attempts, the lock is deleted and the counter reset.
const maxBootstrapWaitAttempts = 5
func RotateBootstrapToken(ctx context.Context, config *config.Control, oldToken string) error {
token, err := util.ReadTokenFromFile(config.Runtime.ServerToken, config.Runtime.ServerCA, config.DataDir)
if err != nil {
return err
}
normalizedToken, err := util.NormalizeToken(token)
if err != nil {
return err
}
storageClient, err := client.New(config.Runtime.EtcdConfig)
if err != nil {
return err
}
defer storageClient.Close()
tokenKey := storageKey(normalizedToken)
var bootstrapList []client.Value
if err := wait.PollImmediateUntilWithContext(ctx, 5*time.Second, func(ctx context.Context) (bool, error) {
bootstrapList, err = storageClient.List(ctx, "/bootstrap", 0)
if err != nil {
return false, err
}
return true, nil
}); err != nil {
return err
}
normalizedOldToken, err := util.NormalizeToken(oldToken)
if err != nil {
return err
}
// reuse the existing migration function to reencrypt bootstrap data with new token
if err := migrateTokens(ctx, bootstrapList, storageClient, "", tokenKey, normalizedToken, normalizedOldToken); err != nil {
return err
}
return nil
}
// Save writes the current ControlRuntimeBootstrap data to the datastore. This contains a complete
// snapshot of the cluster's CA certs and keys, encryption passphrases, etc - encrypted with the join token.
// This is used when bootstrapping a cluster from a managed database or external etcd cluster.
// This is NOT used with embedded etcd, which bootstraps over HTTP.
func Save(ctx context.Context, config *config.Control, override bool) error {
logrus.Info("Saving cluster bootstrap data to datastore")
buf := &bytes.Buffer{}
if err := bootstrap.ReadFromDisk(buf, &config.Runtime.ControlRuntimeBootstrap); err != nil {
return err
}
token := config.Token
if token == "" {
tokenFromFile, err := util.ReadTokenFromFile(config.Runtime.ServerToken, config.Runtime.ServerCA, config.DataDir)
if err != nil {
return err
}
token = tokenFromFile
}
normalizedToken, err := util.NormalizeToken(token)
if err != nil {
return err
}
data, err := encrypt(normalizedToken, buf.Bytes())
if err != nil {
return err
}
storageClient, err := client.New(config.Runtime.EtcdConfig)
if err != nil {
return err
}
defer storageClient.Close()
currentKey, _, err := getBootstrapKeyFromStorage(ctx, storageClient, normalizedToken, token)
if err != nil {
return err
}
// If there's an empty bootstrap key, then we've locked it and can override.
if currentKey != nil && len(currentKey.Data) == 0 {
logrus.Info("Bootstrap key lock is held")
override = true
}
if err := storageClient.Create(ctx, storageKey(normalizedToken), data); err != nil {
if err.Error() == "key exists" {
if override {
bsd, err := bootstrapKeyData(ctx, storageClient)
if err != nil {
return err
}
return storageClient.Update(ctx, storageKey(normalizedToken), bsd.Modified, data)
}
logrus.Warn("Bootstrap key already exists")
return nil
} else if errors.Is(err, rpctypes.ErrGPRCNotSupportedForLearner) {
logrus.Debug("Skipping bootstrap data save on learner")
return nil
}
return err
}
return nil
}
// bootstrapKeyData lists keys stored in the datastore with the prefix "/bootstrap", and
// will return the first such key. It will return an error if not exactly one key is found.
func bootstrapKeyData(ctx context.Context, storageClient client.Client) (*client.Value, error) {
bootstrapList, err := storageClient.List(ctx, "/bootstrap", 0)
if err != nil {
return nil, err
}
if len(bootstrapList) == 0 {
return nil, errors.New("no bootstrap data found")
}
if len(bootstrapList) > 1 {
return nil, errors.New("found multiple bootstrap keys in storage")
}
return &bootstrapList[0], nil
}
// storageBootstrap loads data from the datastore's bootstrap key into the
// ControlRuntimeBootstrap struct. The storage key and encryption passphrase are both derived
// from the join token. If no bootstrap key exists, indicating that data needs to be written
// back to the datastore, this function will set c.saveBootstrap to true and create an empty
// bootstrap key as a lock. This function will not return successfully until either the
// bootstrap key has been locked, or data is read into the struct.
func (c *Cluster) storageBootstrap(ctx context.Context) error {
if c.config.KineTLS {
bootstrapCtx, cancel := context.WithCancel(ctx)
defer func() {
time.Sleep(time.Second)
cancel()
}()
logrus.Info("Starting temporary kine to reconcile with datastore")
if err := c.startStorage(bootstrapCtx, true); err != nil {
return err
}
} else {
if err := c.startStorage(ctx, true); err != nil {
return err
}
}
storageClient, err := client.New(c.config.Runtime.EtcdConfig)
if err != nil {
return err
}
defer storageClient.Close()
token := c.config.Token
if token == "" {
tokenFromFile, err := util.ReadTokenFromFile(c.config.Runtime.ServerToken, c.config.Runtime.ServerCA, c.config.DataDir)
if err != nil {
return err
}
if tokenFromFile == "" {
// No token on disk or from CLI, but we don't know if there's data in the datastore.
// Return here and generate new CA certs and tokens. Note that startup will fail
// later when saving to the datastore if there's already a bootstrap key - but
// that's AFTER generating CA certs and tokens. If the config is updated to set the
// matching key, further startups will still be blocked pending cleanup of the
// "newer" files as per the bootstrap reconciliation code.
c.saveBootstrap = true
return nil
}
token = tokenFromFile
}
normalizedToken, err := util.NormalizeToken(token)
if err != nil {
return err
}
attempts := 0
tokenKey := storageKey(normalizedToken)
return wait.PollImmediateUntilWithContext(ctx, time.Second, func(ctx context.Context) (bool, error) {
attempts++
value, saveBootstrap, err := getBootstrapKeyFromStorage(ctx, storageClient, normalizedToken, token)
c.saveBootstrap = saveBootstrap
if err != nil {
return false, err
}
if value == nil {
// No bootstrap keys found in the datastore - create an empty bootstrap key as a lock to
// ensure that no other node races us to populate it. If we fail to create the key, then
// some other node beat us to it and we should just wait for them to finish.
if err := storageClient.Create(ctx, tokenKey, []byte{}); err != nil {
if err.Error() == "key exists" {
logrus.Info("Bootstrap key already locked - waiting for data to be populated by another server")
return false, nil
}
return false, err
}
logrus.Info("Bootstrap key locked for initial create")
return true, nil
}
if len(value.Data) == 0 {
// Empty (locked) bootstrap key found - check to see if we should continue waiting, or
// delete it and attempt to retake the lock on the next iteration (assuming that the
// other node failed while holding the lock).
if attempts >= maxBootstrapWaitAttempts {
logrus.Info("Bootstrap key lock timed out - deleting lock and retrying")
attempts = 0
if err := storageClient.Delete(ctx, tokenKey, value.Modified); err != nil {
return false, err
}
} else {
logrus.Infof("Bootstrap key is locked - waiting for data to be populated by another server")
}
return false, nil
}
data, err := decrypt(normalizedToken, value.Data)
if err != nil {
return false, err
}
return true, c.ReconcileBootstrapData(ctx, bytes.NewReader(data), &c.config.Runtime.ControlRuntimeBootstrap, false)
})
}
// getBootstrapKeyFromStorage will list all keys that has prefix /bootstrap and will check for key that is
// hashed with empty string and will check for any key that is hashed by different token than the one
// passed to it, it will return error if it finds a key that is hashed with different token and will return
// value if it finds the key hashed by passed token or empty string.
// Upon receiving a "not supported for learner" error from etcd, this function will retry until the context is cancelled.
func getBootstrapKeyFromStorage(ctx context.Context, storageClient client.Client, normalizedToken, oldToken string) (*client.Value, bool, error) {
emptyStringKey := storageKey("")
tokenKey := storageKey(normalizedToken)
var bootstrapList []client.Value
var err error
if err := wait.PollImmediateUntilWithContext(ctx, 5*time.Second, func(ctx context.Context) (bool, error) {
bootstrapList, err = storageClient.List(ctx, "/bootstrap", 0)
if err != nil {
if errors.Is(err, rpctypes.ErrGPRCNotSupportedForLearner) {
return false, nil
}
return false, err
}
return true, nil
}); err != nil {
return nil, false, err
}
if len(bootstrapList) == 0 {
return nil, true, nil
}
if len(bootstrapList) > 1 {
logrus.Warn("found multiple bootstrap keys in storage")
}
// check for empty string key and for old token format with k10 prefix
if err := migrateTokens(ctx, bootstrapList, storageClient, emptyStringKey, tokenKey, normalizedToken, oldToken); err != nil {
return nil, false, err
}
// getting the list of bootstrap again after migrating the empty key
bootstrapList, err = storageClient.List(ctx, "/bootstrap", 0)
if err != nil {
return nil, false, err
}
for _, bootstrapKV := range bootstrapList {
// ensure bootstrap is stored in the current token's key
logrus.Debugf("checking bootstrap key %s against %s", string(bootstrapKV.Key), tokenKey)
if string(bootstrapKV.Key) == tokenKey {
return &bootstrapKV, false, nil
}
}
return nil, false, errors.New("bootstrap data already found and encrypted with different token")
}
// migrateTokens will list all keys that has prefix /bootstrap and will check for key that is
// hashed with empty string and keys that is hashed with old token format before normalizing
// then migrate those and resave only with the normalized token
func migrateTokens(ctx context.Context, bootstrapList []client.Value, storageClient client.Client, emptyStringKey, tokenKey, token, oldToken string) error {
oldTokenKey := storageKey(oldToken)
for _, bootstrapKV := range bootstrapList {
// checking for empty string bootstrap key
logrus.Debug("Comparing ", string(bootstrapKV.Key), " to ", oldTokenKey)
if string(bootstrapKV.Key) == emptyStringKey {
logrus.Warn("Bootstrap data encrypted with empty string, deleting and resaving with token")
if err := doMigrateToken(ctx, storageClient, bootstrapKV, "", emptyStringKey, token, tokenKey); err != nil {
return err
}
} else if string(bootstrapKV.Key) == oldTokenKey && oldTokenKey != tokenKey {
if emptyStringKey != "" {
logrus.Warn("bootstrap data encrypted with old token format string, deleting and resaving with token")
}
if err := doMigrateToken(ctx, storageClient, bootstrapKV, oldToken, oldTokenKey, token, tokenKey); err != nil {
return err
}
}
}
return nil
}
func doMigrateToken(ctx context.Context, storageClient client.Client, keyValue client.Value, oldToken, oldTokenKey, newToken, newTokenKey string) error {
// make sure that the process is non-destructive by decrypting/re-encrypting/storing the data before deleting the old key
data, err := decrypt(oldToken, keyValue.Data)
if err != nil {
return err
}
encryptedData, err := encrypt(newToken, data)
if err != nil {
return err
}
// saving the new encrypted data with the right token key
if err := storageClient.Create(ctx, newTokenKey, encryptedData); err != nil {
if err.Error() == "key exists" {
logrus.Warn("bootstrap key exists")
} else if errors.Is(err, rpctypes.ErrGPRCNotSupportedForLearner) {
logrus.Debug("skipping bootstrap data save on learner")
return nil
} else {
return err
}
}
logrus.Infof("created bootstrap key %s", newTokenKey)
// deleting the old key
if err := storageClient.Delete(ctx, oldTokenKey, keyValue.Modified); err != nil {
logrus.Warnf("failed to delete old bootstrap key %s", oldTokenKey)
}
return nil
}