meta/redis:support unix socket for redis (#2319)

docs/en/reference/how_to_setup_metadata_engine.md

@@ -38,7 +38,11 @@ JuiceFS requires Redis 4.0+
 When using Redis as the metadata storage engine, the following format is usually used to access the database:
 
 ```shell
+# use tcp
 redis[s]://[<username>:<password>@]<host>[:<port>]/<db>
+
+# use unix socket 
+unix://[<username>:<password>@]<socket-file-path>?db=<db>
 ```
 
 Where `[]` enclosed are optional and the rest are mandatory.
@@ -119,7 +123,11 @@ Other PostgreSQL-compatible databases (such as CockroachDB) can also be used as
 When using PostgreSQL as the metadata storage engine, you need to create a database manually before creating the file system by following the format below:
 
 ```shell
+# use tcp
 postgres://<username>[:<password>]@<host>[:5432]/<database-name>[?parameters]
+
+# use unix socket
+postgres:///<database-name>?host=<socket-directories-path>
 ```
 
 Where `[]` enclosed are optional and the rest are mandatory.
@@ -178,7 +186,11 @@ Additional parameters can be appended to the metadata URL. More details can be s
 When using MySQL as the metadata storage engine, you need to create a database manually before create the file system. The command with the following format is usually used to access the database:
 
 ```shell
+# use tcp
 mysql://<username>[:<password>]@(<host>:3306)/<database-name>
+
+# use unix socket 
+mysql://<username>[:<password>]@unix(<socket-file-path>)/<database-name>
 ```
 
 :::note

docs/zh_cn/reference/how_to_setup_metadata_engine.md

@@ -36,7 +36,11 @@ JuiceFS 要求 Redis 4.0+ 版本
 使用 Redis 作为元数据存储引擎时，通常使用以下格式访问数据库：
 
 ```shell
+# 使用 tcp 方式
 redis[s]://[<username>:<password>@]<host>[:<port>]/<db>
+
+# 使用 unix socket 方式
+unix://[<username>:<password>@]<socket-file-path>?db=<db>
 ```
 
 其中，`[]` 括起来的是可选项，其它部分为必选项。
@@ -117,7 +121,11 @@ KeyDB 的数据复制是异步的，使用 `Active Active` "双活"功能可能
 使用 PostgreSQL 作为元数据引擎时，需要提前手动创建数据库，使用如下的格式来指定参数：
 
 ```shell
+# tcp 方式
 postgres://<username>[:<password>]@<host>[:5432]/<database-name>[?parameters]
+
+# 使用 unix socket 方式
+postgres:///<database-name>?host=<socket-directories-path>
 ```
 
 其中，`[]` 括起来的是可选项，其它部分为必选项。
@@ -176,7 +184,11 @@ $ juicefs format --storage s3 \
 使用 MySQL 作为元数据存储引擎时，需要提前手动创建数据库，通常使用以下格式访问数据库：
 
 ```shell
+# 使用 tcp 方式
 mysql://<username>[:<password>]@(<host>:3306)/<database-name>
+
+# 使用 unix socket 方式
+mysql://<username>[:<password>]@unix(<socket-file-path>)/<database-name>
 ```
 
 :::note 注意

pkg/meta/redis.go

@@ -84,27 +84,27 @@ var _ Meta = &redisMeta{}
 func init() {
 	Register("redis", newRedisMeta)
 	Register("rediss", newRedisMeta)
+	Register("unix", newRedisMeta)
 }
 
 // newRedisMeta return a meta store using Redis.
 func newRedisMeta(driver, addr string, conf *Config) (Meta, error) {
 	uri := driver + "://" + addr
-	var query queryMap
-	if p := strings.Index(uri, "?"); p > 0 && p+1 < len(uri) {
-		if q, err := url.ParseQuery(uri[p+1:]); err == nil {
-			logger.Debugf("parsed query parameters: %v", q)
-			query = queryMap{q}
-			uri = uri[:p]
-		} else {
-			return nil, fmt.Errorf("parse query %s: %s", uri[p+1:], err)
-		}
-	}
 	u, err := url.Parse(uri)
 	if err != nil {
 		return nil, fmt.Errorf("url parse %s: %s", uri, err)
 	}
+	values := u.Query()
+	query := queryMap{&values}
+	minRetryBackoff := query.duration("min-retry-backoff", "min_retry_backoff", time.Millisecond*20)
+	maxRetryBackoff := query.duration("max-retry-backoff", "max_retry_backoff", time.Second*10)
+	readTimeout := query.duration("read-timeout", "read_timeout", time.Second*30)
+	writeTimeout := query.duration("write-timeout", "write_timeout", time.Second*5)
+	routeRead := query.pop("route-read")
+	u.RawQuery = values.Encode()
+
 	hosts := u.Host
-	opt, err := redis.ParseURL(uri)
+	opt, err := redis.ParseURL(u.String())
 	if err != nil {
 		return nil, fmt.Errorf("redis parse %s: %s", uri, err)
 	}
@@ -118,10 +118,10 @@ func newRedisMeta(driver, addr string, conf *Config) (Meta, error) {
 	if opt.MaxRetries == 0 {
 		opt.MaxRetries = -1 // Redis use -1 to disable retries
 	}
-	opt.MinRetryBackoff = query.duration("min-retry-backoff", time.Millisecond*20)
-	opt.MaxRetryBackoff = query.duration("max-retry-backoff", time.Second*10)
-	opt.ReadTimeout = query.duration("read-timeout", time.Second*30)
-	opt.WriteTimeout = query.duration("write-timeout", time.Second*5)
+	opt.MinRetryBackoff = minRetryBackoff
+	opt.MaxRetryBackoff = maxRetryBackoff
+	opt.ReadTimeout = readTimeout
+	opt.WriteTimeout = writeTimeout
 	var rdb redis.UniversalClient
 	var prefix string
 	if strings.Contains(hosts, ",") && strings.Index(hosts, ",") < strings.Index(hosts, ":") {
@@ -153,7 +153,7 @@ func newRedisMeta(driver, addr string, conf *Config) (Meta, error) {
 		fopt.WriteTimeout = opt.WriteTimeout
 		if conf.ReadOnly {
 			// NOTE: RouteByLatency and RouteRandomly are not supported since they require cluster client
-			fopt.SlaveOnly = query.Get("route-read") == "replica"
+			fopt.SlaveOnly = routeRead == "replica"
 		}
 		rdb = redis.NewFailoverClient(&fopt)
 	} else {
@@ -179,7 +179,7 @@ func newRedisMeta(driver, addr string, conf *Config) (Meta, error) {
 			copt.ReadTimeout = opt.ReadTimeout
 			copt.WriteTimeout = opt.WriteTimeout
 			if conf.ReadOnly {
-				switch query.Get("route-read") {
+				switch routeRead {
 				case "random":
 					copt.RouteRandomly = true
 				case "latency":

pkg/meta/utils.go

@@ -61,14 +61,20 @@ type freeID struct {
 var logger = utils.GetLogger("juicefs")
 
 type queryMap struct {
-	url.Values
+	*url.Values
 }
 
-func (qm *queryMap) duration(key string, d time.Duration) time.Duration {
+func (qm *queryMap) duration(key, originalKey string, d time.Duration) time.Duration {
 	val := qm.Get(key)
 	if val == "" {
-		return d
+		oVal := qm.Get(originalKey)
+		if oVal == "" {
+			return d
+		}
+		val = oVal
 	}
+
+	qm.Del(key)
 	if dur, err := time.ParseDuration(val); err == nil {
 		return dur
 	} else {
@@ -77,6 +83,11 @@ func (qm *queryMap) duration(key string, d time.Duration) time.Duration {
 	}
 }
 
+func (qm *queryMap) pop(key string) string {
+	defer qm.Del(key)
+	return qm.Get(key)
+}
+
 func errno(err error) syscall.Errno {
 	if err == nil {
 		return 0