minio/cmd/etcd.go
2020-11-04 13:06:05 -08:00

86 lines
2.6 KiB
Go

/*
* MinIO Cloud Storage, (C) 2019 MinIO, Inc.
*
* 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 cmd
import (
"context"
"errors"
"fmt"
etcd "go.etcd.io/etcd/v3/clientv3"
)
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))
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))
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)
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 {
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
}