CVL Changes #3: Multi-db instance support (#20)

Adding multi-db instance support based on db config file.
So, now instead of hardcoded DB endpoint, it is read from a configuration file.

cvl/cvl_api.go

@@ -22,7 +22,6 @@ package cvl
 import (
  "fmt"
  "encoding/json"
- "github.com/go-redis/redis"
  "path/filepath"
  "github.com/Azure/sonic-mgmt-common/cvl/internal/yparser"
  . "github.com/Azure/sonic-mgmt-common/cvl/internal/util"
@@ -135,6 +134,13 @@ func Initialize() CVLRetCode {
  return CVL_SUCCESS
  }
 
+ //Initialize redis Client 
+ redisClient = NewDbClient("CONFIG_DB")
+
+ if (redisClient == nil) {
+ CVL_LOG(FATAL, "Unable to connect to Redis Config DB Server")
+ return CVL_ERROR
+ }
  //Scan schema directory to get all schema files
  modelFiles, err := filepath.Glob(CVL_SCHEMA + "/*.yin")
  if err != nil {
@@ -169,16 +175,6 @@ func Initialize() CVLRetCode {
 
  //Initialize redis Client 
 
- redisClient = redis.NewClient(&redis.Options{
- Addr: ":6379",
- Password: "", // no password set
- DB: int(CONFIG_DB), // use APP DB
- })
-
- if (redisClient == nil) {
- CVL_LOG(FATAL, "Unable to connect with Redis Config DB")
- return CVL_ERROR
- }
 
  //Load lua script into redis
  loadLuaScript()

cvl/cvl_test.go

@@ -196,17 +196,12 @@ func compareErrorDetails(cvlErr cvl.CVLErrorInfo, expCode cvl.CVLRetCode, errApp
 }
 
 func getConfigDbClient() *redis.Client {
- rclient := redis.NewClient(&redis.Options{
- Network: "tcp",
- Addr: "localhost:6379",
- Password: "", // no password set
- DB: 4,
- DialTimeout: 0,
- })
- _, err := rclient.Ping().Result()
- if err != nil {
- fmt.Printf("failed to connect to redis server %v", err)
+ rclient := NewDbClient("CONFIG_DB")
+
+ if rclient == nil {
+ panic("Unable to connect to Redis Config DB Server")
  }
+
  return rclient
 }
 

cvl/internal/util/util.go

@@ -29,11 +29,15 @@ import (
  "syscall"
  "strings"
  "flag"
+ "github.com/go-redis/redis"
  log "github.com/golang/glog"
 )
 
 var CVL_SCHEMA string = "/usr/sbin/schema/"
 var CVL_CFG_FILE string = "/usr/sbin/cvl_cfg.json"
+const SONIC_DB_CONFIG_FILE string = "/var/run/redis/sonic-db/database_config.json"
+const ENV_VAR_SONIC_DB_CONFIG_FILE = "DB_CONFIG_PATH"
+var sonic_db_config = make(map[string]interface{})
 
 //package init function 
 func init() {
@@ -44,6 +48,9 @@ func init() {
  if (os.Getenv("CVL_CFG_FILE") != "") {
  CVL_CFG_FILE = os.Getenv("CVL_CFG_FILE")
  }
+
+ //Initialize DB settings
+ dbCfgInit()
 }
 
 var cvlCfgMap map[string]string
@@ -253,3 +260,184 @@ func SkipSemanticValidation() bool {
 
  return false
 }
+
+//Function to read Redis DB configuration from file.
+//In absence of the file, it uses default config for CONFIG_DB
+//so that CVL UT will pass in development environment.
+func dbCfgInit() {
+ defaultDBConfig := `{
+ "INSTANCES": {
+ "redis":{
+ "hostname" : "127.0.0.1",
+ "port" : 6379
+ }
+ },
+ "DATABASES" : {
+ "CONFIG_DB" : {
+ "id" : 4,
+ "separator": "|",
+ "instance" : "redis"
+ },
+ "STATE_DB" : {
+ "id" : 6,
+ "separator": "|",
+ "instance" : "redis"
+ }
+ }
+ }`
+
+ dbCfgFile := ""
+
+ //Check if multi-db config file is present
+ if _, errF := os.Stat(SONIC_DB_CONFIG_FILE); !os.IsNotExist(errF) {
+ dbCfgFile = SONIC_DB_CONFIG_FILE
+ } else {
+ //Check if multi-db config file is specified in environment
+ if fileName := os.Getenv(ENV_VAR_SONIC_DB_CONFIG_FILE); fileName != "" {
+ if _, errF := os.Stat(fileName); !os.IsNotExist(errF) {
+ dbCfgFile = fileName
+ }
+ }
+ }
+
+ if dbCfgFile != "" {
+ //Read from multi-db config file
+ data, err := ioutil.ReadFile(dbCfgFile)
+ if err != nil {
+ panic(err)
+ } else {
+ err = json.Unmarshal([]byte(data), &sonic_db_config)
+ if err != nil {
+ panic(err)
+ }
+ }
+ } else {
+ //No multi-db config file is present.
+ //Use default config for CONFIG_DB setting, this avoids CVL UT failure
+ //in absence of at multi-db config file
+ err := json.Unmarshal([]byte(defaultDBConfig), &sonic_db_config)
+ if err != nil {
+ panic(err)
+ }
+ }
+}
+
+//Get list of DB
+func getDbList()(map[string]interface{}) {
+ db_list, ok := sonic_db_config["DATABASES"].(map[string]interface{})
+ if !ok {
+ panic(fmt.Errorf("DATABASES' is not valid key in %s!",
+ SONIC_DB_CONFIG_FILE))
+ }
+ return db_list
+}
+
+//Get DB instance based on given DB name
+func getDbInst(dbName string)(map[string]interface{}) {
+ db, ok := sonic_db_config["DATABASES"].(map[string]interface{})[dbName]
+ if !ok {
+ panic(fmt.Errorf("database name '%v' is not valid in %s !",
+ dbName, SONIC_DB_CONFIG_FILE))
+ }
+ inst_name, ok := db.(map[string]interface{})["instance"]
+ if !ok {
+ panic(fmt.Errorf("'instance' is not a valid field in %s !",
+ SONIC_DB_CONFIG_FILE))
+ }
+ inst, ok := sonic_db_config["INSTANCES"].(map[string]interface{})[inst_name.(string)]
+ if !ok {
+ panic(fmt.Errorf("instance name '%v' is not valid in %s !",
+ inst_name, SONIC_DB_CONFIG_FILE))
+ }
+ return inst.(map[string]interface{})
+}
+
+//GetDbSeparator Get DB separator based on given DB name
+func GetDbSeparator(dbName string)(string) {
+ db_list := getDbList()
+ separator, ok := db_list[dbName].(map[string]interface{})["separator"]
+ if !ok {
+ panic(fmt.Errorf("'separator' is not a valid field in %s !",
+ SONIC_DB_CONFIG_FILE))
+ }
+ return separator.(string)
+}
+
+//GetDbId Get DB id on given db name
+func GetDbId(dbName string)(int) {
+ db_list := getDbList()
+ id, ok := db_list[dbName].(map[string]interface{})["id"]
+ if !ok {
+ panic(fmt.Errorf("'id' is not a valid field in %s !",
+ SONIC_DB_CONFIG_FILE))
+ }
+ return int(id.(float64))
+}
+
+//GetDbSock Get DB socket path
+func GetDbSock(dbName string)(string) {
+ inst := getDbInst(dbName)
+ unix_socket_path, ok := inst["unix_socket_path"]
+ if !ok {
+ CVL_LEVEL_LOG(INFO, "'unix_socket_path' is not " +
+ "a valid field in %s !", SONIC_DB_CONFIG_FILE)
+
+ return ""
+ }
+
+ return unix_socket_path.(string)
+}
+
+//GetDbTcpAddr Get DB TCP endpoint
+func GetDbTcpAddr(dbName string)(string) {
+ inst := getDbInst(dbName)
+ hostname, ok := inst["hostname"]
+ if !ok {
+ panic(fmt.Errorf("'hostname' is not a valid field in %s !",
+ SONIC_DB_CONFIG_FILE))
+ }
+
+ port, ok1 := inst["port"]
+ if !ok1 {
+ panic(fmt.Errorf("'port' is not a valid field in %s !",
+ SONIC_DB_CONFIG_FILE))
+ }
+
+ return fmt.Sprintf("%v:%v", hostname, port)
+}
+
+//NewDbClient Get new redis client 
+func NewDbClient(dbName string) *redis.Client {
+ var redisClient *redis.Client = nil
+
+ //Try unix domain socket first
+ if dbSock := GetDbSock(dbName); dbSock != "" {
+ redisClient = redis.NewClient(&redis.Options{
+ Network: "unix",
+ Addr: dbSock,
+ Password: "",
+ DB: GetDbId(dbName),
+ })
+ } else {
+ //Otherwise, use TCP socket
+ redisClient = redis.NewClient(&redis.Options{
+ Network: "tcp",
+ Addr: GetDbTcpAddr(dbName),
+ Password: "",
+ DB: GetDbId(dbName),
+ })
+ }
+
+ if (redisClient == nil) {
+ return nil
+ }
+
+ //Check the connectivity
+ _, err := redisClient.Ping().Result()
+ if err != nil {
+ CVL_LEVEL_LOG(ERROR, "Failed to connect to Redis server %v", err)
+ return nil
+ }
+
+ return redisClient
+}