minio/cmd/config-common.go
Harshavardhana 0a28c28a8c Avoid code which looks at local files when etcd is configured (#7144)
This situation happens only in gateway nas which supports
etcd based `config.json` to support all FS mode features.

The issue was we would try to migrate something which doesn't
exist when etcd is configured which leads to inconsistent
server configs in memory.

This PR fixes this situation by properly loading config after
initialization, avoiding backend disk config migration to be
done only if etcd is not configured.
2019-01-28 13:31:35 -08:00

152 lines
4.9 KiB
Go

/*
* Minio Cloud Storage, (C) 2018 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 (
"bytes"
"context"
"errors"
"fmt"
etcd "github.com/coreos/etcd/clientv3"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/hash"
)
var errConfigNotFound = errors.New("config file not found")
func readConfig(ctx context.Context, objAPI ObjectLayer, configFile string) ([]byte, error) {
var buffer bytes.Buffer
// Read entire content by setting size to -1
if err := objAPI.GetObject(ctx, minioMetaBucket, configFile, 0, -1, &buffer, "", ObjectOptions{}); err != nil {
// Treat object not found as config not found.
if isErrObjectNotFound(err) {
return nil, errConfigNotFound
}
logger.GetReqInfo(ctx).AppendTags("configFile", configFile)
logger.LogIf(ctx, err)
return nil, err
}
// Return config not found on empty content.
if buffer.Len() == 0 {
return nil, errConfigNotFound
}
return buffer.Bytes(), nil
}
func deleteConfigEtcd(ctx context.Context, client *etcd.Client, configFile string) error {
_, err := client.Delete(ctx, configFile)
return err
}
func deleteConfig(ctx context.Context, objAPI ObjectLayer, configFile string) error {
return objAPI.DeleteObject(ctx, minioMetaBucket, configFile)
}
func saveConfigEtcd(ctx context.Context, client *etcd.Client, configFile string, data []byte) error {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
_, err := client.Put(timeoutCtx, configFile, string(data))
if err == context.DeadlineExceeded {
return fmt.Errorf("etcd setup is unreachable, please check your endpoints %s", client.Endpoints())
} else if err != nil {
return fmt.Errorf("unexpected error %s returned by etcd setup, please check your endpoints %s", err, client.Endpoints())
}
return nil
}
func saveConfig(ctx context.Context, objAPI ObjectLayer, configFile string, data []byte) error {
hashReader, err := hash.NewReader(bytes.NewReader(data), int64(len(data)), "", getSHA256Hash(data), int64(len(data)))
if err != nil {
return err
}
_, err = objAPI.PutObject(ctx, minioMetaBucket, configFile, NewPutObjReader(hashReader, nil, nil), nil, ObjectOptions{})
return err
}
func readConfigEtcd(ctx context.Context, client *etcd.Client, configFile string) ([]byte, error) {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
resp, err := client.Get(timeoutCtx, configFile)
if err != nil {
if err == context.DeadlineExceeded {
return nil, fmt.Errorf("etcd setup is unreachable, please check your endpoints %s", client.Endpoints())
}
return nil, fmt.Errorf("unexpected error %s returned by etcd setup, please check your endpoints %s", err, client.Endpoints())
}
if resp.Count == 0 {
return nil, errConfigNotFound
}
for _, ev := range resp.Kvs {
if string(ev.Key) == configFile {
return ev.Value, nil
}
}
return nil, errConfigNotFound
}
// watchConfigEtcd - watches for changes on `configFile` on etcd and loads them.
func watchConfigEtcd(objAPI ObjectLayer, configFile string, loadCfgFn func(ObjectLayer) error) {
ctx, cancel := context.WithTimeout(context.Background(), defaultContextTimeout)
defer cancel()
for watchResp := range globalEtcdClient.Watch(ctx, configFile) {
for _, event := range watchResp.Events {
if event.IsModify() || event.IsCreate() {
loadCfgFn(objAPI)
}
}
}
}
func checkConfigEtcd(ctx context.Context, client *etcd.Client, configFile string) error {
timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
defer cancel()
resp, err := client.Get(timeoutCtx, configFile)
if err != nil {
if err == context.DeadlineExceeded {
return fmt.Errorf("etcd setup is unreachable, please check your endpoints %s", client.Endpoints())
}
return fmt.Errorf("unexpected error %s returned by etcd setup, please check your endpoints %s", err, client.Endpoints())
}
if resp.Count == 0 {
return errConfigNotFound
}
return nil
}
func checkConfig(ctx context.Context, objAPI ObjectLayer, configFile string) error {
if globalEtcdClient != nil {
return checkConfigEtcd(ctx, globalEtcdClient, configFile)
}
if _, err := objAPI.GetObjectInfo(ctx, minioMetaBucket, configFile, ObjectOptions{}); err != nil {
// Treat object not found as config not found.
if isErrObjectNotFound(err) {
return errConfigNotFound
}
logger.GetReqInfo(ctx).AppendTags("configFile", configFile)
logger.LogIf(ctx, err)
return err
}
return nil
}