package redis import ( "errors" "fmt" "net" "net/url" "time" "github.com/FZambia/sentinel" "github.com/gomodule/redigo/redis" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/promauto" "gitlab.com/gitlab-org/labkit/log" "gitlab.com/gitlab-org/gitlab/workhorse/internal/config" "gitlab.com/gitlab-org/gitlab/workhorse/internal/helper" ) var ( pool *redis.Pool sntnl *sentinel.Sentinel ) const ( // Max Idle Connections in the pool. defaultMaxIdle = 1 // Max Active Connections in the pool. defaultMaxActive = 1 // Timeout for Read operations on the pool. 1 second is technically overkill, // it's just for sanity. defaultReadTimeout = 1 * time.Second // Timeout for Write operations on the pool. 1 second is technically overkill, // it's just for sanity. defaultWriteTimeout = 1 * time.Second // Timeout before killing Idle connections in the pool. 3 minutes seemed good. // If you _actually_ hit this timeout often, you should consider turning of // redis-support since it's not necessary at that point... defaultIdleTimeout = 3 * time.Minute // KeepAlivePeriod is to keep a TCP connection open for an extended period of // time without being killed. This is used both in the pool, and in the // worker-connection. // See https://en.wikipedia.org/wiki/Keepalive#TCP_keepalive for more // information. defaultKeepAlivePeriod = 5 * time.Minute ) var ( totalConnections = promauto.NewCounter( prometheus.CounterOpts{ Name: "gitlab_workhorse_redis_total_connections", Help: "How many connections gitlab-workhorse has opened in total. Can be used to track Redis connection rate for this process", }, ) errorCounter = promauto.NewCounterVec( prometheus.CounterOpts{ Name: "gitlab_workhorse_redis_errors", Help: "Counts different types of Redis errors encountered by workhorse, by type and destination (redis, sentinel)", }, []string{"type", "dst"}, ) ) func sentinelConn(master string, urls []config.TomlURL) *sentinel.Sentinel { if len(urls) == 0 { return nil } var addrs []string for _, url := range urls { h := url.URL.String() log.WithFields(log.Fields{ "scheme": url.URL.Scheme, "host": url.URL.Host, }).Printf("redis: using sentinel") addrs = append(addrs, h) } return &sentinel.Sentinel{ Addrs: addrs, MasterName: master, Dial: func(addr string) (redis.Conn, error) { // This timeout is recommended for Sentinel-support according to the guidelines. // https://redis.io/topics/sentinel-clients#redis-service-discovery-via-sentinel // For every address it should try to connect to the Sentinel, // using a short timeout (in the order of a few hundreds of milliseconds). timeout := 500 * time.Millisecond url := helper.URLMustParse(addr) var c redis.Conn var err error options := []redis.DialOption{ redis.DialConnectTimeout(timeout), redis.DialReadTimeout(timeout), redis.DialWriteTimeout(timeout), } if url.Scheme == "redis" || url.Scheme == "rediss" { c, err = redis.DialURL(addr, options...) } else { c, err = redis.Dial("tcp", url.Host, options...) } if err != nil { errorCounter.WithLabelValues("dial", "sentinel").Inc() return nil, err } return c, nil }, } } var poolDialFunc func() (redis.Conn, error) var workerDialFunc func() (redis.Conn, error) func timeoutDialOptions(cfg *config.RedisConfig) []redis.DialOption { return []redis.DialOption{ redis.DialReadTimeout(defaultReadTimeout), redis.DialWriteTimeout(defaultWriteTimeout), } } func dialOptionsBuilder(cfg *config.RedisConfig, setTimeouts bool) []redis.DialOption { var dopts []redis.DialOption if setTimeouts { dopts = timeoutDialOptions(cfg) } if cfg == nil { return dopts } if cfg.Password != "" { dopts = append(dopts, redis.DialPassword(cfg.Password)) } if cfg.DB != nil { dopts = append(dopts, redis.DialDatabase(*cfg.DB)) } return dopts } func keepAliveDialer(network, address string) (net.Conn, error) { addr, err := net.ResolveTCPAddr(network, address) if err != nil { return nil, err } tc, err := net.DialTCP(network, nil, addr) if err != nil { return nil, err } if err := tc.SetKeepAlive(true); err != nil { return nil, err } if err := tc.SetKeepAlivePeriod(defaultKeepAlivePeriod); err != nil { return nil, err } return tc, nil } type redisDialerFunc func() (redis.Conn, error) func sentinelDialer(dopts []redis.DialOption) redisDialerFunc { return func() (redis.Conn, error) { address, err := sntnl.MasterAddr() if err != nil { errorCounter.WithLabelValues("master", "sentinel").Inc() return nil, err } dopts = append(dopts, redis.DialNetDial(keepAliveDialer)) return redisDial("tcp", address, dopts...) } } func defaultDialer(dopts []redis.DialOption, url url.URL) redisDialerFunc { return func() (redis.Conn, error) { if url.Scheme == "unix" { return redisDial(url.Scheme, url.Path, dopts...) } dopts = append(dopts, redis.DialNetDial(keepAliveDialer)) // redis.DialURL only works with redis[s]:// URLs if url.Scheme == "redis" || url.Scheme == "rediss" { return redisURLDial(url, dopts...) } return redisDial(url.Scheme, url.Host, dopts...) } } func redisURLDial(url url.URL, options ...redis.DialOption) (redis.Conn, error) { log.WithFields(log.Fields{ "scheme": url.Scheme, "address": url.Host, }).Printf("redis: dialing") return redis.DialURL(url.String(), options...) } func redisDial(network, address string, options ...redis.DialOption) (redis.Conn, error) { log.WithFields(log.Fields{ "network": network, "address": address, }).Printf("redis: dialing") return redis.Dial(network, address, options...) } func countDialer(dialer redisDialerFunc) redisDialerFunc { return func() (redis.Conn, error) { c, err := dialer() if err != nil { errorCounter.WithLabelValues("dial", "redis").Inc() } else { totalConnections.Inc() } return c, err } } // DefaultDialFunc should always used. Only exception is for unit-tests. func DefaultDialFunc(cfg *config.RedisConfig, setReadTimeout bool) func() (redis.Conn, error) { dopts := dialOptionsBuilder(cfg, setReadTimeout) if sntnl != nil { return countDialer(sentinelDialer(dopts)) } return countDialer(defaultDialer(dopts, cfg.URL.URL)) } // Configure redis-connection func Configure(cfg *config.RedisConfig, dialFunc func(*config.RedisConfig, bool) func() (redis.Conn, error)) { if cfg == nil { return } maxIdle := defaultMaxIdle if cfg.MaxIdle != nil { maxIdle = *cfg.MaxIdle } maxActive := defaultMaxActive if cfg.MaxActive != nil { maxActive = *cfg.MaxActive } sntnl = sentinelConn(cfg.SentinelMaster, cfg.Sentinel) workerDialFunc = dialFunc(cfg, false) poolDialFunc = dialFunc(cfg, true) pool = &redis.Pool{ MaxIdle: maxIdle, // Keep at most X hot connections MaxActive: maxActive, // Keep at most X live connections, 0 means unlimited IdleTimeout: defaultIdleTimeout, // X time until an unused connection is closed Dial: poolDialFunc, Wait: true, } if sntnl != nil { pool.TestOnBorrow = func(c redis.Conn, t time.Time) error { if !sentinel.TestRole(c, "master") { return errors.New("role check failed") } return nil } } } // Get a connection for the Redis-pool func Get() redis.Conn { if pool != nil { return pool.Get() } return nil } // GetString fetches the value of a key in Redis as a string func GetString(key string) (string, error) { conn := Get() if conn == nil { return "", fmt.Errorf("redis: could not get connection from pool") } defer conn.Close() return redis.String(conn.Do("GET", key)) }