add user middleware chain function (#1913)

* add user middleware chain function

* fix staticcheck SA4006

* chang code Implementation style

Co-authored-by: kemq1 <kemq1@spdb.com.cn>

rest/server.go

@@ -7,6 +7,7 @@ import (
 	"path"
 	"time"
 
+	"github.com/justinas/alice"
 	"github.com/zeromicro/go-zero/core/logx"
 	"github.com/zeromicro/go-zero/rest/handler"
 	"github.com/zeromicro/go-zero/rest/httpx"
@@ -242,6 +243,17 @@ func WithTLSConfig(cfg *tls.Config) RunOption {
 	}
 }
 
+// WithChain returns a RunOption that with given chain config.
+func WithChain(middlewares ...func(http.Handler) http.Handler) RunOption {
+	return func(svr *Server) {
+		chain := alice.New()
+		for _, middleware := range middlewares {
+			chain = chain.Append(middleware)
+		}
+		svr.ngin.setChainConfig(&chain)
+	}
+}
+
 // WithUnauthorizedCallback returns a RunOption that with given unauthorized callback set.
 func WithUnauthorizedCallback(callback handler.UnauthorizedCallback) RunOption {
 	return func(svr *Server) {