redis: support sentinel (#31)

* let redis support sentinel

let redis support sentinel

* Update .travis.yml

Co-authored-by: ᴜɴᴋɴᴡᴏɴ <u@gogs.io>

.travis.yml

@@ -4,7 +4,7 @@ go:
   # - 1.6.x: bad for Redis 
   # - 1.7.x: bad for MySQL
   # - 1.8.x: bad for MySQL
-  - 1.9.x
+  # - 1.9.x: bad for MySQL
   - 1.10.x
   - 1.11.x
   - 1.12.x

redis/redis.go

@@ -123,6 +123,11 @@ func (p *RedisProvider) Init(maxlifetime int64, configs string) (err error) {
 		return err
 	}
 
+	section, err := cfg.GetSection("")
+	if err == nil && section != nil && section.Key("ha_mode").Value() == "sentinel" {
+		return p.initSentinel(cfg)
+	}
+
 	opt := &redis.Options{
 		Network: "tcp",
 	}
@@ -154,6 +159,49 @@ func (p *RedisProvider) Init(maxlifetime int64, configs string) (err error) {
 	return p.c.Ping().Err()
 }
 
+func (p *RedisProvider) initSentinel(cfg *ini.File) (err error) {
+	opt := &redis.FailoverOptions{}
+
+	for k, v := range cfg.Section("").KeysHash() {
+		switch k {
+		case "master_name":
+			opt.MasterName = v
+		case "sentinel_Addrs":
+			opt.SentinelAddrs = strings.Split(v, "|")
+		case "password":
+			opt.Password = v
+		case "db":
+			opt.DB = com.StrTo(v).MustInt64()
+		case "pool_size":
+			opt.PoolSize = com.StrTo(v).MustInt()
+		case "dial_timeout":
+			opt.DialTimeout, err = time.ParseDuration(v + "s")
+			if err != nil {
+				return fmt.Errorf("error parsing dial timeout: %v", err)
+			}
+		case "read_timeout":
+			opt.ReadTimeout, err = time.ParseDuration(v + "s")
+			if err != nil {
+				return fmt.Errorf("error parsing read timeout: %v", err)
+			}
+		case "write_timeout":
+			opt.WriteTimeout, err = time.ParseDuration(v + "s")
+			if err != nil {
+				return fmt.Errorf("error parsing write timeout: %v", err)
+			}
+		case "idle_timeout":
+			opt.IdleTimeout, err = time.ParseDuration(v + "s")
+			if err != nil {
+				return fmt.Errorf("error parsing idle timeout: %v", err)
+			}
+		case "prefix":
+			p.prefix = v
+		}
+	}
+	p.c = redis.NewFailoverClient(opt)
+	return p.c.Ping().Err()
+}
+
 // Read returns raw session store by session ID.
 func (p *RedisProvider) Read(sid string) (session.RawStore, error) {
 	psid := p.prefix + sid