Add DB/password config for backends and ignore SELECT/AUTH commands

- Add PrimaryDB, PrimaryPassword, SecondaryDB, SecondaryPassword to ProxyConfig
- Add DB and Password fields to BackendOptions, passed to go-redis client
- Add CLI flags: -primary-db, -primary-password, -secondary-db, -secondary-password
- Silently accept SELECT and AUTH commands (return OK without forwarding)
  since DB/auth are configured at the connection-pool level

Author: bootjp

cmd/redis-proxy/main.go

@@ -32,7 +32,11 @@ func run() error {
 
 	flag.StringVar(&cfg.ListenAddr, "listen", cfg.ListenAddr, "Proxy listen address")
 	flag.StringVar(&cfg.PrimaryAddr, "primary", cfg.PrimaryAddr, "Primary (Redis) address")
+	flag.IntVar(&cfg.PrimaryDB, "primary-db", cfg.PrimaryDB, "Primary Redis DB number")
+	flag.StringVar(&cfg.PrimaryPassword, "primary-password", cfg.PrimaryPassword, "Primary Redis password")
 	flag.StringVar(&cfg.SecondaryAddr, "secondary", cfg.SecondaryAddr, "Secondary (ElasticKV) address")
+	flag.IntVar(&cfg.SecondaryDB, "secondary-db", cfg.SecondaryDB, "Secondary Redis DB number")
+	flag.StringVar(&cfg.SecondaryPassword, "secondary-password", cfg.SecondaryPassword, "Secondary Redis password")
 	flag.StringVar(&modeStr, "mode", "dual-write", "Proxy mode: redis-only, dual-write, dual-write-shadow, elastickv-primary, elastickv-only")
 	flag.DurationVar(&cfg.SecondaryTimeout, "secondary-timeout", cfg.SecondaryTimeout, "Secondary write timeout")
 	flag.DurationVar(&cfg.ShadowTimeout, "shadow-timeout", cfg.ShadowTimeout, "Shadow read timeout")
@@ -59,14 +63,21 @@ func run() error {
 	metrics := proxy.NewProxyMetrics(reg)
 
 	// Backends
+	primaryOpts := proxy.DefaultBackendOptions()
+	primaryOpts.DB = cfg.PrimaryDB
+	primaryOpts.Password = cfg.PrimaryPassword
+	secondaryOpts := proxy.DefaultBackendOptions()
+	secondaryOpts.DB = cfg.SecondaryDB
+	secondaryOpts.Password = cfg.SecondaryPassword
+
 	var primary, secondary proxy.Backend
 	switch cfg.Mode {
 	case proxy.ModeElasticKVPrimary, proxy.ModeElasticKVOnly:
-		primary = proxy.NewRedisBackend(cfg.SecondaryAddr, "elastickv")
-		secondary = proxy.NewRedisBackend(cfg.PrimaryAddr, "redis")
+		primary = proxy.NewRedisBackendWithOptions(cfg.SecondaryAddr, "elastickv", secondaryOpts)
+		secondary = proxy.NewRedisBackendWithOptions(cfg.PrimaryAddr, "redis", primaryOpts)
 	case proxy.ModeRedisOnly, proxy.ModeDualWrite, proxy.ModeDualWriteShadow:
-		primary = proxy.NewRedisBackend(cfg.PrimaryAddr, "redis")
-		secondary = proxy.NewRedisBackend(cfg.SecondaryAddr, "elastickv")
+		primary = proxy.NewRedisBackendWithOptions(cfg.PrimaryAddr, "redis", primaryOpts)
+		secondary = proxy.NewRedisBackendWithOptions(cfg.SecondaryAddr, "elastickv", secondaryOpts)
 	}
 	defer primary.Close()
 	defer secondary.Close()

proxy/backend.go

@@ -29,6 +29,8 @@ type Backend interface {
 
 // BackendOptions configures the underlying go-redis connection pool.
 type BackendOptions struct {
+	DB           int
+	Password     string
 	PoolSize     int
 	DialTimeout  time.Duration
 	ReadTimeout  time.Duration
@@ -67,6 +69,8 @@ func NewRedisBackendWithOptions(addr string, name string, opts BackendOptions) *
 	return &RedisBackend{
 		client: redis.NewClient(&redis.Options{
 			Addr:         addr,
+			DB:           opts.DB,
+			Password:     opts.Password,
 			PoolSize:     opts.PoolSize,
 			DialTimeout:  opts.DialTimeout,
 			ReadTimeout:  opts.ReadTimeout,

proxy/config.go

@@ -49,16 +49,20 @@ func (m ProxyMode) String() string {
 
 // ProxyConfig holds all configuration for the dual-write proxy.
 type ProxyConfig struct {
-	ListenAddr       string
-	PrimaryAddr      string
-	SecondaryAddr    string
-	Mode             ProxyMode
-	SecondaryTimeout time.Duration
-	ShadowTimeout    time.Duration
-	SentryDSN        string
-	SentryEnv        string
-	SentrySampleRate float64
-	MetricsAddr      string
+	ListenAddr        string
+	PrimaryAddr       string
+	PrimaryDB         int
+	PrimaryPassword   string
+	SecondaryAddr     string
+	SecondaryDB       int
+	SecondaryPassword string
+	Mode              ProxyMode
+	SecondaryTimeout  time.Duration
+	ShadowTimeout     time.Duration
+	SentryDSN         string
+	SentryEnv         string
+	SentrySampleRate  float64
+	MetricsAddr       string
 }
 
 // DefaultConfig returns a ProxyConfig with sensible defaults.

proxy/proxy.go

@@ -283,6 +283,13 @@ func (p *ProxyServer) handleAdmin(conn redcon.Conn, args [][]byte) {
 		return
 	}
 
+	// SELECT and AUTH are handled at the connection-pool level via config.
+	// Silently accept them so clients don't break.
+	if name == "SELECT" || name == "AUTH" {
+		conn.WriteString("OK")
+		return
+	}
+
 	resp, err := p.dual.Admin(context.Background(), args)
 	writeResponse(conn, resp, err)
 }

proxy/pubsub.go

@@ -263,6 +263,12 @@ func (s *pubsubSession) handleTxnInSession(name string, args [][]byte) bool {
 
 // dispatchRegularCommand sends a non-transaction, non-special command to the backend.
 func (s *pubsubSession) dispatchRegularCommand(name string, args [][]byte) {
+	// SELECT and AUTH are handled at the connection-pool level; accept silently.
+	if name == "SELECT" || name == "AUTH" {
+		s.writeString("OK")
+		return
+	}
+
 	cat := ClassifyCommand(name, args[1:])
 	ctx := context.Background()