feat: add codis proxy info command (OpenAtomFoundation#2688)

* add codis proxy info command

* safe init for slice

* use append

* init in-place

* remove assign

codis/pkg/proxy/session.go

@@ -14,6 +14,7 @@ import (
 
 	"pika/codis/v2/pkg/models"
 	"pika/codis/v2/pkg/proxy/redis"
+	"pika/codis/v2/pkg/utils"
 	"pika/codis/v2/pkg/utils/errors"
 	"pika/codis/v2/pkg/utils/log"
 	"pika/codis/v2/pkg/utils/sync2/atomic2"
@@ -299,6 +300,8 @@ func (s *Session) handleRequest(r *Request, d *Router) error {
 		return s.handleQuit(r)
 	case "AUTH":
 		return s.handleAuth(r)
+	case "CODIS.INFO":
+		return s.handleCodisInfo(r)
 	}
 
 	if !s.authorized {
@@ -361,6 +364,22 @@ func (s *Session) handleAuth(r *Request) error {
 	return nil
 }
 
+func (s *Session) handleCodisInfo(r *Request) error {
+	if len(r.Multi) != 0 {
+		r.Resp = redis.NewErrorf("ERR wrong number of arguments for 'CODIS.INFO' command")
+		return nil
+	}
+
+	r.Resp = redis.NewArray([]*redis.Resp{
+		redis.NewString([]byte(utils.Version)),
+		redis.NewString([]byte(utils.Compile)),
+		redis.NewString([]byte(fmt.Sprintf("admin addr: %s", s.proxy.model.AdminAddr))),
+		redis.NewString([]byte(fmt.Sprintf("start time: %s", s.proxy.model.StartTime))),
+	})
+
+	return nil
+}
+
 func (s *Session) handleSelect(r *Request) error {
 	if len(r.Multi) != 2 {
 		r.Resp = redis.NewErrorf("ERR wrong number of arguments for 'SELECT' command")