minio/cmd/etcd.go

93 lines
2.9 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"context"
"errors"
"fmt"
"github.com/minio/minio/internal/logger"
etcd "go.etcd.io/etcd/client/v3"
)
var errEtcdUnreachable = errors.New("etcd is unreachable, please check your endpoints")
func etcdErrToErr(err error, etcdEndpoints []string) error {
if err == nil {
return nil
}
switch err {
case context.DeadlineExceeded:
return fmt.Errorf("%w %s", errEtcdUnreachable, etcdEndpoints)
default:
return fmt.Errorf("unexpected error %w from etcd, please check your endpoints %s", err, etcdEndpoints)
}
}
func saveKeyEtcdWithTTL(ctx context.Context, client *etcd.Client, key string, data []byte, ttl int64) error {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
lease, err := client.Grant(timeoutCtx, ttl)
if err != nil {
return etcdErrToErr(err, client.Endpoints())
}
_, err = client.Put(timeoutCtx, key, string(data), etcd.WithLease(lease.ID))
logger.LogIf(ctx, err)
return etcdErrToErr(err, client.Endpoints())
}
func saveKeyEtcd(ctx context.Context, client *etcd.Client, key string, data []byte, opts ...options) error {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
if len(opts) > 0 {
return saveKeyEtcdWithTTL(ctx, client, key, data, opts[0].ttl)
}
_, err := client.Put(timeoutCtx, key, string(data))
logger.LogIf(ctx, err)
return etcdErrToErr(err, client.Endpoints())
}
func deleteKeyEtcd(ctx context.Context, client *etcd.Client, key string) error {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
_, err := client.Delete(timeoutCtx, key)
logger.LogIf(ctx, err)
return etcdErrToErr(err, client.Endpoints())
}
func readKeyEtcd(ctx context.Context, client *etcd.Client, key string) ([]byte, error) {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
resp, err := client.Get(timeoutCtx, key)
if err != nil {
logger.LogIf(ctx, err)
return nil, etcdErrToErr(err, client.Endpoints())
}
if resp.Count == 0 {
return nil, errConfigNotFound
}
for _, ev := range resp.Kvs {
if string(ev.Key) == key {
return ev.Value, nil
}
}
return nil, errConfigNotFound
}