blob: 24988bea7cf79e1989119a6245efcf97edc586ec [file] [log] [blame]
* Copyright 2018-present Open Networking Foundation
* 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
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
package config
import (
const (
defaultkvStoreConfigPath = "config"
defaultkvStoreDataPathPrefix = "service/voltha"
kvStorePathSeparator = "/"
// ConfigType represents the type for which config is created inside the kvstore
// For example, loglevel
type ConfigType int
const (
ConfigTypeLogLevel ConfigType = iota
func (c ConfigType) String() string {
return [...]string{"loglevel", "metadata", "kafka"}[c]
// ChangeEvent represents the event recieved from watch
// For example, Put Event
type ChangeEvent int
const (
Put ChangeEvent = iota
func (ce ChangeEvent) String() string {
return [...]string{"Put", "Delete"}[ce]
// ConfigChangeEvent represents config for the events recieved from watch
// For example,ChangeType is Put ,ConfigAttribute default
type ConfigChangeEvent struct {
ChangeType ChangeEvent
ConfigAttribute string
// ConfigManager is a wrapper over Backend to maintain Configuration of voltha components
// in kvstore based persistent storage
type ConfigManager struct {
Backend *db.Backend
KVStoreConfigPrefix string
KVStoreDataPathPrefix string
// ComponentConfig represents a category of configuration for a specific VOLTHA component type
// stored in a persistent storage pointed to by Config Manager
// For example, one ComponentConfig instance will be created for loglevel config type for rw-core
// component while another ComponentConfig instance will refer to connection config type for same
// rw-core component. So, there can be multiple ComponentConfig instance created per component
// pointing to different category of configuration.
// Configuration pointed to be by ComponentConfig is stored in kvstore as a list of key/value pairs
// under the hierarchical tree with following base path
// <Backend Prefix Path>/<Config Prefix>/<Component Name>/<Config Type>/
// For example, rw-core ComponentConfig for loglevel config entries will be stored under following path
// /voltha/service/config/rw-core/loglevel/
type ComponentConfig struct {
cManager *ConfigManager
componentLabel string
configType ConfigType
changeEventChan chan *ConfigChangeEvent
kvStoreEventChan chan *kvstore.Event
func NewConfigManager(kvClient kvstore.Client, kvStoreType, kvStoreAddress string, kvStoreTimeout time.Duration) *ConfigManager {
var kvStorePrefix string
if prefix, present := os.LookupEnv("KV_STORE_DATAPATH_PREFIX"); present {
kvStorePrefix = prefix
logger.Infow("KV_STORE_DATAPATH_PREFIX env variable is set, ", log.Fields{"kvStoreDataPathPrefix": kvStorePrefix})
} else {
kvStorePrefix = defaultkvStoreDataPathPrefix
logger.Infow("KV_STORE_DATAPATH_PREFIX env variable is not set, using default", log.Fields{"kvStoreDataPathPrefix": defaultkvStoreDataPathPrefix})
return &ConfigManager{
KVStoreConfigPrefix: defaultkvStoreConfigPath,
KVStoreDataPathPrefix: kvStorePrefix,
Backend: &db.Backend{
Client: kvClient,
StoreType: kvStoreType,
Address: kvStoreAddress,
Timeout: kvStoreTimeout,
PathPrefix: kvStorePrefix,
// RetrieveComponentList list the component Names for which loglevel is stored in kvstore
func (c *ConfigManager) RetrieveComponentList(ctx context.Context, configType ConfigType) ([]string, error) {
data, err := c.Backend.List(ctx, c.KVStoreConfigPrefix)
if err != nil {
return nil, err
// Looping through the data recieved from the Backend for config
// Trimming and Splitting the required key and value from data and storing as componentName,PackageName and Level
// For Example, recieved key would be <Backend Prefix Path>/<Config Prefix>/<Component Name>/<Config Type>/default and value \"DEBUG\"
// Then in default will be stored as PackageName,componentName as <Component Name> and DEBUG will be stored as value in List struct
ccPathPrefix := kvStorePathSeparator + configType.String() + kvStorePathSeparator
pathPrefix := c.KVStoreDataPathPrefix + kvStorePathSeparator + c.KVStoreConfigPrefix + kvStorePathSeparator
var list []string
keys := make(map[string]interface{})
for attr := range data {
cname := strings.TrimPrefix(attr, pathPrefix)
cName := strings.SplitN(cname, ccPathPrefix, 2)
if len(cName) != 2 {
if _, exist := keys[cName[0]]; !exist {
keys[cName[0]] = nil
list = append(list, cName[0])
return list, nil
// Initialize the component config
func (cm *ConfigManager) InitComponentConfig(componentLabel string, configType ConfigType) *ComponentConfig {
return &ComponentConfig{
componentLabel: componentLabel,
configType: configType,
cManager: cm,
changeEventChan: nil,
kvStoreEventChan: nil,
func (c *ComponentConfig) makeConfigPath() string {
cType := c.configType.String()
return c.cManager.KVStoreConfigPrefix + kvStorePathSeparator +
c.componentLabel + kvStorePathSeparator + cType
// MonitorForConfigChange watch on the subkeys for the given key
// Any changes to the subkeys for the given key will return an event channel
// Then Event channel will be processed and new event channel with required values will be created and return
// For example, rw-core will be watching on <Backend Prefix Path>/<Config Prefix>/<Component Name>/<Config Type>/
// will return an event channel for PUT,DELETE eventType.
// Then values from event channel will be processed and stored in kvStoreEventChan.
func (c *ComponentConfig) MonitorForConfigChange(ctx context.Context) chan *ConfigChangeEvent {
key := c.makeConfigPath()
logger.Debugw("monitoring-for-config-change", log.Fields{"key": key})
c.changeEventChan = make(chan *ConfigChangeEvent, 1)
c.kvStoreEventChan = c.cManager.Backend.CreateWatch(ctx, key, true)
go c.processKVStoreWatchEvents()
return c.changeEventChan
// processKVStoreWatchEvents process event channel recieved from the Backend for any ChangeType
// It checks for the EventType is valid or not.For the valid EventTypes creates ConfigChangeEvent and send it on channel
func (c *ComponentConfig) processKVStoreWatchEvents() {
ccKeyPrefix := c.makeConfigPath()
logger.Debugw("processing-kvstore-event-change", log.Fields{"key-prefix": ccKeyPrefix})
ccPathPrefix := c.cManager.Backend.PathPrefix + ccKeyPrefix + kvStorePathSeparator
for watchResp := range c.kvStoreEventChan {
if watchResp.EventType == kvstore.CONNECTIONDOWN || watchResp.EventType == kvstore.UNKNOWN {
logger.Warnw("received-invalid-change-type-in-watch-channel-from-kvstore", log.Fields{"change-type": watchResp.EventType})
// populating the configAttribute from the received Key
// For Example, Key received would be <Backend Prefix Path>/<Config Prefix>/<Component Name>/<Config Type>/default
// Storing default in configAttribute variable
ky := fmt.Sprintf("%s", watchResp.Key)
c.changeEventChan <- &ConfigChangeEvent{
ChangeType: ChangeEvent(watchResp.EventType),
ConfigAttribute: strings.TrimPrefix(ky, ccPathPrefix),
// Retrieves value of a specific config key. Value of key is returned in String format
func (c *ComponentConfig) Retrieve(ctx context.Context, configKey string) (string, error) {
key := c.makeConfigPath() + "/" + configKey
logger.Debugw("retrieving-config", log.Fields{"key": key})
if kvpair, err := c.cManager.Backend.Get(ctx, key); err != nil {
return "", err
} else {
if kvpair == nil {
return "", fmt.Errorf("config-key-does-not-exist : %s", key)
value := strings.Trim(fmt.Sprintf("%s", kvpair.Value), "\"")
logger.Debugw("retrieved-config", log.Fields{"key": key, "value": value})
return value, nil
func (c *ComponentConfig) RetrieveAll(ctx context.Context) (map[string]string, error) {
key := c.makeConfigPath()
logger.Debugw("retreiving-list", log.Fields{"key": key})
data, err := c.cManager.Backend.List(ctx, key)
if err != nil {
return nil, err
// Looping through the data recieved from the Backend for the given key
// Trimming the required key and value from data and storing as key/value pair
// For Example, recieved key would be <Backend Prefix Path>/<Config Prefix>/<Component Name>/<Config Type>/default and value \"DEBUG\"
// Then in default will be stored as key and DEBUG will be stored as value in map[string]string
res := make(map[string]string)
ccPathPrefix := c.cManager.Backend.PathPrefix + kvStorePathSeparator + key + kvStorePathSeparator
for attr, val := range data {
res[strings.TrimPrefix(attr, ccPathPrefix)] = strings.Trim(fmt.Sprintf("%s", val.Value), "\"")
return res, nil
func (c *ComponentConfig) Save(ctx context.Context, configKey string, configValue string) error {
key := c.makeConfigPath() + "/" + configKey
logger.Debugw("saving-config", log.Fields{"key": key, "value": configValue})
//save the data for update config
if err := c.cManager.Backend.Put(ctx, key, configValue); err != nil {
return err
return nil
func (c *ComponentConfig) Delete(ctx context.Context, configKey string) error {
//construct key using makeConfigPath
key := c.makeConfigPath() + "/" + configKey
logger.Debugw("deleting-config", log.Fields{"key": key})
//delete the config
if err := c.cManager.Backend.Delete(ctx, key); err != nil {
return err
return nil