minio/cmd/config.go
Harshavardhana b7226f4c82 Add transaction lock when migrating configs (#6878)
When migrating configs it happens often that some
servers fail to start due to version mismatch etc.

Hold a transaction lock such that all servers get
serialized.
2018-11-28 17:38:23 -08:00

215 lines
5.3 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"
"encoding/json"
"os"
"path"
"runtime"
"strings"
"time"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/quick"
)
const (
minioConfigPrefix = "config"
// Minio configuration file.
minioConfigFile = "config.json"
// Minio backup file
minioConfigBackupFile = minioConfigFile + ".backup"
)
func saveServerConfig(ctx context.Context, objAPI ObjectLayer, config *serverConfig) error {
if err := quick.CheckData(config); err != nil {
return err
}
data, err := json.MarshalIndent(config, "", "\t")
if err != nil {
return err
}
configFile := path.Join(minioConfigPrefix, minioConfigFile)
if globalEtcdClient != nil {
timeoutCtx, cancel := context.WithTimeout(ctx, 5*time.Minute)
_, err = globalEtcdClient.Put(timeoutCtx, configFile, string(data))
defer cancel()
return err
}
// Create a backup of the current config
oldData, err := readConfig(ctx, objAPI, configFile)
if err == nil {
backupConfigFile := path.Join(minioConfigPrefix, minioConfigBackupFile)
if err = saveConfig(ctx, objAPI, backupConfigFile, oldData); err != nil {
return err
}
} else {
if err != errConfigNotFound {
return err
}
}
// Save the new config in the std config path
return saveConfig(ctx, objAPI, configFile, data)
}
func readServerConfig(ctx context.Context, objAPI ObjectLayer) (*serverConfig, error) {
var configData []byte
var err error
configFile := path.Join(minioConfigPrefix, minioConfigFile)
if globalEtcdClient != nil {
configData, err = readConfigEtcd(ctx, globalEtcdClient, configFile)
} else {
configData, err = readConfig(ctx, objAPI, configFile)
}
if err != nil {
return nil, err
}
if runtime.GOOS == "windows" {
configData = bytes.Replace(configData, []byte("\r\n"), []byte("\n"), -1)
}
if err = quick.CheckDuplicateKeys(string(configData)); err != nil {
return nil, err
}
var config = &serverConfig{}
if err = json.Unmarshal(configData, config); err != nil {
return nil, err
}
if err = quick.CheckData(config); err != nil {
return nil, err
}
return config, nil
}
// ConfigSys - config system.
type ConfigSys struct{}
// Load - load config.json.
func (sys *ConfigSys) Load(objAPI ObjectLayer) error {
return sys.Init(objAPI)
}
// Init - initializes config system from config.json.
func (sys *ConfigSys) Init(objAPI ObjectLayer) error {
if objAPI == nil {
return errInvalidArgument
}
doneCh := make(chan struct{})
defer close(doneCh)
// Initializing configuration needs a retry mechanism for
// the following reasons:
// - Read quorum is lost just after the initialization
// of the object layer.
// - Write quorum not met when upgrading configuration
// version is needed.
retryTimerCh := newRetryTimerSimple(doneCh)
for {
select {
case _ = <-retryTimerCh:
err := initConfig(objAPI)
if err != nil {
if strings.Contains(err.Error(), InsufficientReadQuorum{}.Error()) ||
strings.Contains(err.Error(), InsufficientWriteQuorum{}.Error()) {
logger.Info("Waiting for configuration to be initialized..")
continue
}
return err
}
return nil
}
}
}
// NewConfigSys - creates new config system object.
func NewConfigSys() *ConfigSys {
return &ConfigSys{}
}
// Initialize and load config from remote etcd or local config directory
func initConfig(objAPI ObjectLayer) error {
if objAPI == nil {
return errServerNotInitialized
}
if globalEtcdClient != nil {
ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
resp, err := globalEtcdClient.Get(ctx, getConfigFile())
cancel()
if err == nil && resp.Count > 0 {
if err = migrateConfig(); err != nil {
return err
}
// Migrates etcd ${HOME}/.minio/config.json to '/config/config.json'
if err := migrateConfigToMinioSys(objAPI); err != nil {
return err
}
}
} else {
if isFile(getConfigFile()) {
if err := migrateConfig(); err != nil {
return err
}
}
// Migrates ${HOME}/.minio/config.json or config.json.deprecated
// to '<export_path>/.minio.sys/config/config.json'
// ignore if the file doesn't exist.
if err := migrateConfigToMinioSys(objAPI); err != nil && !os.IsNotExist(err) {
return err
}
}
configFile := path.Join(minioConfigPrefix, minioConfigFile)
// Watch config for changes and reloads them in-memory.
go watchConfig(objAPI, configFile, loadConfig)
if err := checkConfig(context.Background(), objAPI, configFile); err != nil {
if err == errConfigNotFound {
// Config file does not exist, we create it fresh and return upon success.
if err = newSrvConfig(objAPI); err != nil {
return err
}
} else {
return err
}
}
if err := migrateMinioSysConfig(objAPI); err != nil {
return err
}
return loadConfig(objAPI)
}