feat/env: support get the parameter from environment (#21)

README.md

@@ -127,9 +127,9 @@ Provide the mechanism to custom the nacos parameter `vo.ConfigParam`.
 
 | Variable Name | Default Value | Introduction |
 | ------------------------- | ---------------------------------- | --------------------------------- |
-| Address               | 127.0.0.1                          | Nacos server address |
-| Port               | 8848                               | Nacos server port            |
-| NamespaceID                 |                                    | The namespaceID of Nacos 中的 namespace Id |
+| Address               | 127.0.0.1                          | Nacos server address, may use the environment of `serverAddr` |
+| Port               | 8848                               | Nacos server port, may use the environment of `serverPort` |
+| NamespaceID                 |                                    | The namespaceID of Nacos, may use the environment of `namespace` |
 | ClientDataIDFormat              | {{.ClientServiceName}}.{{.ServerServiceName}}.{{.Category}}  | Use go [template](https://pkg.go.dev/text/template) syntax rendering to generate the appropriate ID, and use `ClientServiceName` `ServiceName` `Category` three metadata that can be customised          |
 | ServerDataIDFormat              | {{.ServerServiceName}}.{{.Category}}  | Use go [template](https://pkg.go.dev/text/template) syntax rendering to generate the appropriate ID, and use `ServiceName` `Category` two metadatas that can be customised          |
 | Group               | DEFAULT_GROUP                      | Use fixed values or dynamic rendering. Usage is the same as configDataId.          |

README_CN.md

@@ -125,9 +125,9 @@ func main() {
 
 | 参数 | 变量默认值 | 作用 |
 | ------------------------- | ---------------------------------- | --------------------------------- |
-| Address               | 127.0.0.1                          | nacos 服务器地址 |
-| Port               | 8848                               | nacos 服务器端口            |
-| NamespaceID                 |                                    | nacos 中的 namespace Id |
+| Address               | 127.0.0.1                          | nacos 服务器地址, 如果参数为空使用 serverAddr 环境变量值 |
+| Port               | 8848                               | nacos 服务器端口, 如果参数为空使用 serverPort 环境变量值 |
+| NamespaceID                 |                                    | nacos 中的 namespace Id, 如果参数为空使用 namespace 环境变量值 |
 | ClientDataIDFormat              | {{.ClientServiceName}}.{{.ServerServiceName}}.{{.Category}}  | 使用 go [template](https://pkg.go.dev/text/template) 语法渲染生成对应的 ID, 使用 `ClientServiceName` `ServiceName` `Category` 三个元数据          |
 | ServerDataIDFormat              | {{.ServerServiceName}}.{{.Category}}  | 使用 go [template](https://pkg.go.dev/text/template) 语法渲染生成对应的 ID, 使用 `ServiceName` `Category` 两个元数据          |
 | Group               | DEFAULT_GROUP                      | 使用固定值，也可以动态渲染，用法同 DataIDFormat          |

nacos/env.go

@@ -0,0 +1,57 @@
+// Copyright 2023 CloudWeGo Authors
+//
+// Licensed 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 nacos
+
+import (
+	"os"
+	"strconv"
+
+	"github.com/cloudwego/kitex/pkg/klog"
+)
+
+// keep consistent with the env with alicloud
+const (
+	NacosAliServerAddrEnv = "serverAddr"
+	NacosAliPortEnv       = "serverPort"
+	NacosAliNamespaceEnv  = "namespace"
+)
+
+// NacosPort Get Nacos port from environment variables
+func NacosPort() uint64 {
+	portText := os.Getenv(NacosAliPortEnv)
+	if len(portText) == 0 {
+		return NacosDefaultPort
+	}
+	port, err := strconv.ParseInt(portText, 10, 64)
+	if err != nil {
+		klog.Errorf("ParseInt failed,err:%s", err.Error())
+		return NacosDefaultPort
+	}
+	return uint64(port)
+}
+
+// NacosAddr Get Nacos addr from environment variables
+func NacosAddr() string {
+	addr := os.Getenv(NacosAliServerAddrEnv)
+	if len(addr) == 0 {
+		return NacosDefaultServerAddr
+	}
+	return addr
+}
+
+// NacosNameSpaceId Get Nacos namespace id from environment variables
+func NacosNameSpaceId() string {
+	return os.Getenv(NacosDefaultConfigGroup)
+}

nacos/nacos.go

@@ -83,20 +83,23 @@ type Options struct {
 // NewClient Create a default Nacos client
 func NewClient(opts Options) (Client, error) {
 	if opts.Address == "" {
-		opts.Address = NacosDefaultServerAddr
+		opts.Address = NacosAddr()
 	}
 	if opts.Port == 0 {
-		opts.Port = NacosDefaultPort
+		opts.Port = NacosPort()
+	}
+	if opts.NamespaceID == "" {
+		opts.NamespaceID = NacosNameSpaceId()
+	}
+	if opts.Group == "" {
+		opts.Group = NacosDefaultConfigGroup
 	}
 	if opts.CustomLogger == nil {
 		opts.CustomLogger = NewCustomNacosLogger()
 	}
 	if opts.ConfigParser == nil {
 		opts.ConfigParser = defaultConfigParse()
 	}
-	if opts.Group == "" {
-		opts.Group = NacosDefaultConfigGroup
-	}
 	if opts.ServerDataIDFormat == "" {
 		opts.ServerDataIDFormat = NacosDefaultServerDataID
 	}