refactor: improve admin router (arana-db#407)

docker-compose.yaml

@@ -65,6 +65,7 @@ services:
     depends_on:
       - mysql
       - etcd
+    restart: on-failure
 
   arana-admin:
     container_name: arana-admin
@@ -79,6 +80,7 @@ services:
       - ./conf/bootstrap.docker.yaml:/etc/arana/bootstrap.yaml:ro
     depends_on:
       - etcd
+    restart: on-failure
 
 networks:
   local:

pkg/admin/admin.api.yaml

@@ -1,4 +1,3 @@
-#
 # Licensed to the Apache Software Foundation (ASF) under one or more
 # contributor license agreements.  See the NOTICE file distributed with
 # this work for additional information regarding copyright ownership.
@@ -13,7 +12,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-#
 
 openapi: 3.0.3
 info:

pkg/admin/admin.go

@@ -22,7 +22,6 @@ import (
 	"errors"
 	"io"
 	"net"
-	"net/http"
 	"os"
 	"strings"
 )
@@ -36,6 +35,7 @@ import (
 )
 
 import (
+	"github.com/arana-db/arana/pkg/admin/exception"
 	"github.com/arana-db/arana/pkg/boot"
 	"github.com/arana-db/arana/pkg/constants"
 )
@@ -46,7 +46,17 @@ var NotFoundError = errors.New("resource not found")
 
 var _hooks []Hook
 
-type Hook func(router gin.IRoutes)
+type Hook func(Router)
+
+type Handler func(*gin.Context) error
+
+type Router interface {
+	GET(string, Handler)
+	POST(string, Handler)
+	DELETE(string, Handler)
+	PATCH(string, Handler)
+	PUT(string, Handler)
+}
 
 func Register(hook Hook) {
 	_hooks = append(_hooks, hook)
@@ -100,17 +110,10 @@ func (srv *Server) Listen(addr string) error {
 	})
 	srv.engine.Use(gin.Logger())
 	srv.engine.Use(gin.Recovery())
-	srv.engine.Use(
-		ErrorHandler(
-			Map(NotFoundError).
-				ToResponse(func(c *gin.Context, err error) {
-					c.Status(http.StatusNotFound)
-					_, _ = c.Writer.WriteString(err.Error())
-				}),
-		))
+	srv.engine.Use(CORSMiddleware())
 
 	for _, hook := range _hooks {
-		hook(srv.engine)
+		hook((*myRouter)(srv.engine))
 	}
 
 	if srv.l, err = c.Listen(context.Background(), "tcp", addr); err != nil {
@@ -124,3 +127,43 @@ func GetService(c *gin.Context) Service {
 	v, _ := c.Get(K)
 	return v.(Service)
 }
+
+type myRouter gin.Engine
+
+func (w *myRouter) GET(s string, handler Handler) {
+	(*gin.Engine)(w).GET(s, w.wrapper(handler))
+}
+
+func (w *myRouter) POST(s string, handler Handler) {
+	(*gin.Engine)(w).POST(s, w.wrapper(handler))
+}
+
+func (w *myRouter) DELETE(s string, handler Handler) {
+	(*gin.Engine)(w).DELETE(s, w.wrapper(handler))
+}
+
+func (w *myRouter) PATCH(s string, handler Handler) {
+	(*gin.Engine)(w).PATCH(s, w.wrapper(handler))
+}
+
+func (w *myRouter) PUT(s string, handler Handler) {
+	(*gin.Engine)(w).PUT(s, w.wrapper(handler))
+}
+
+func (w *myRouter) wrapper(handler Handler) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		err := handler(c)
+		if err == nil {
+			return
+		}
+		switch e := err.(type) {
+		case exception.APIException:
+			c.JSON(e.Code.HttpStatus(), e)
+		case *exception.APIException:
+			c.JSON(e.Code.HttpStatus(), e)
+		default:
+			ee := exception.Wrap(exception.CodeUnknownError, e)
+			c.JSON(ee.Code.HttpStatus(), ee)
+		}
+	}
+}

pkg/admin/cors.go

@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package admin
+
+import (
+	"github.com/gin-gonic/gin"
+)
+
+func CORSMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
+		c.Writer.Header().Set("Access-Control-Allow-Credentials", "true")
+		c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
+		c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET, PUT, PATCH, DELETE")
+
+		if c.Request.Method == "OPTIONS" {
+			c.AbortWithStatus(204)
+			return
+		}
+
+		c.Next()
+	}
+}

pkg/admin/exception/exception.go

@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package exception
+
+import (
+	"fmt"
+)
+
+const (
+	CodeServerError Code = 1000 + iota
+	CodeNotFound
+	CodeInvalidParams
+	CodeAuth
+	CodeUnknownError
+)
+
+var _httpStatus = map[Code]int{
+	CodeNotFound:      404,
+	CodeInvalidParams: 400,
+	CodeAuth:          401,
+	CodeServerError:   500,
+}
+
+type Code uint16
+
+func (ec Code) HttpStatus() int {
+	hc, ok := _httpStatus[ec]
+	if ok {
+		return hc
+	}
+	return 500
+}
+
+type APIException struct {
+	Code    Code   `json:"code"`
+	Message string `json:"message"`
+}
+
+func (ae APIException) Error() string {
+	return fmt.Sprintf("ERR-%05d: %s", ae.Code, ae.Message)
+}
+
+func New(code Code, format string, args ...interface{}) APIException {
+	return APIException{
+		Code:    code,
+		Message: fmt.Sprintf(format, args...),
+	}
+}
+
+func Wrap(code Code, err error) APIException {
+	return APIException{
+		Code:    code,
+		Message: err.Error(),
+	}
+}