feat: use shared redis client to maximize pooling usage (#39)

internal/setup/redis.go

@@ -1,14 +1,38 @@
 package setup
 
 import (
+	"context"
+	"strings"
+	"sync"
 	"time"
 
 	"forge.cadoles.com/cadoles/bouncer/internal/config"
+	"github.com/pkg/errors"
 	"github.com/redis/go-redis/v9"
+	"gitlab.com/wpetit/goweb/logger"
 )
 
+var clients sync.Map
+
+func NewSharedClient(conf config.RedisConfig) redis.UniversalClient {
+	key := strings.Join(conf.Adresses, "|") + "|" + string(conf.Master)
+
+	value, exists := clients.Load(key)
+	if exists {
+		if client, ok := (value).(redis.UniversalClient); ok {
+			return client
+		}
+	}
+
+	client := newRedisClient(conf)
+
+	clients.Store(key, client)
+
+	return client
+}
+
 func newRedisClient(conf config.RedisConfig) redis.UniversalClient {
-	return redis.NewUniversalClient(&redis.UniversalOptions{
+	client := redis.NewUniversalClient(&redis.UniversalOptions{
 		Addrs:                 conf.Adresses,
 		MasterName:            string(conf.Master),
 		ReadTimeout:           time.Duration(conf.ReadTimeout),
@@ -16,5 +40,33 @@ func newRedisClient(conf config.RedisConfig) redis.UniversalClient {
 		DialTimeout:           time.Duration(conf.DialTimeout),
 		RouteByLatency:        true,
 		ContextTimeoutEnabled: true,
+		MaxRetries:            int(conf.MaxRetries),
 	})
+
+	go func() {
+		ctx := logger.With(context.Background(),
+			logger.F("adresses", conf.Adresses),
+			logger.F("master", conf.Master),
+		)
+
+		timer := time.NewTicker(time.Duration(conf.PingInterval))
+		defer timer.Stop()
+
+		connected := true
+
+		for range timer.C {
+			if _, err := client.Ping(ctx).Result(); err != nil {
+				logger.Error(ctx, "redis disconnected", logger.E(errors.WithStack(err)))
+				connected = false
+				continue
+			}
+
+			if !connected {
+				logger.Info(ctx, "redis reconnected")
+				connected = true
+			}
+		}
+	}()
+
+	return client
 }