聊聊nacos-sdk-go的NacosServer

序

本文主要研究一下nacos-sdk-go的NacosServer

NacosServer

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

type NacosServer struct {
	sync.RWMutex
	securityLogin       security.AuthClient
	serverList          []constant.ServerConfig
	httpAgent           http_agent.IHttpAgent
	timeoutMs           uint64
	endpoint            string
	lastSrvRefTime      int64
	vipSrvRefInterMills int64
}

NacosServer定义了securityLogin、serverList、httpAgent、timeoutMs、endpoint、lastSrvRefTime、vipSrvRefInterMills属性

NewNacosServer

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func NewNacosServer(serverList []constant.ServerConfig, clientCfg constant.ClientConfig, httpAgent http_agent.IHttpAgent, timeoutMs uint64, endpoint string) (NacosServer, error) {
	if len(serverList) == 0 && endpoint == "" {
		return NacosServer{}, errors.New("both serverlist  and  endpoint are empty")
	}

	securityLogin := security.NewAuthClient(clientCfg, serverList, httpAgent)

	ns := NacosServer{
		serverList:          serverList,
		securityLogin:       securityLogin,
		httpAgent:           httpAgent,
		timeoutMs:           timeoutMs,
		endpoint:            endpoint,
		vipSrvRefInterMills: 10000,
	}
	ns.initRefreshSrvIfNeed()
	_, err := securityLogin.Login()

	if err != nil {
		return ns, err
	}

	securityLogin.AutoRefresh()
	return ns, nil
}

NewNacosServer创建NacosServer及securityLogin，然后执行securityLogin.AutoRefresh()

callConfigServer

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) callConfigServer(api string, params map[string]string, newHeaders map[string]string,
	method string, curServer string, contextPath string, timeoutMS uint64) (result string, err error) {
	if contextPath == "" {
		contextPath = constant.WEB_CONTEXT
	}

	signHeaders := getSignHeaders(params, newHeaders)

	url := "http://" + curServer + contextPath + api
	headers := map[string][]string{}
	for k, v := range newHeaders {
		if k != "accessKey" && k != "secretKey" {
			headers[k] = []string{v}
		}
	}
	headers["Client-Version"] = []string{constant.CLIENT_VERSION}
	headers["User-Agent"] = []string{constant.CLIENT_VERSION}
	//headers["Accept-Encoding"] = []string{"gzip,deflate,sdch"}
	headers["Connection"] = []string{"Keep-Alive"}
	headers["exConfigInfo"] = []string{"true"}
	uid, err := uuid.NewV4()
	if err != nil {
		return
	}
	headers["RequestId"] = []string{uid.String()}
	headers["Request-Module"] = []string{"Naming"}
	headers["Content-Type"] = []string{"application/x-www-form-urlencoded;charset=utf-8"}
	headers["Spas-AccessKey"] = []string{newHeaders["accessKey"]}
	headers["Timestamp"] = []string{signHeaders["timeStamp"]}
	headers["Spas-Signature"] = []string{signHeaders["Spas-Signature"]}
	injectSecurityInfo(server, params)

	var response *http.Response
	response, err = server.httpAgent.Request(method, url, headers, timeoutMS, params)
	if err != nil {
		return
	}
	var bytes []byte
	bytes, err = ioutil.ReadAll(response.Body)
	defer response.Body.Close()
	if err != nil {
		return
	}
	result = string(bytes)
	if response.StatusCode == 200 {
		return
	} else {
		err = nacos_error.NewNacosError(strconv.Itoa(response.StatusCode), string(bytes), nil)
		return
	}
}

callConfigServer方法通过injectSecurityInfo注入SecurityInfo，然后通过server.httpAgent.Request(method, url, headers, timeoutMS, params)执行请求

callServer

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) callServer(api string, params map[string]string, method string, curServer string, contextPath string) (result string, err error) {
	if contextPath == "" {
		contextPath = constant.WEB_CONTEXT
	}

	url := "http://" + curServer + contextPath + api
	headers := map[string][]string{}
	headers["Client-Version"] = []string{constant.CLIENT_VERSION}
	headers["User-Agent"] = []string{constant.CLIENT_VERSION}
	//headers["Accept-Encoding"] = []string{"gzip,deflate,sdch"}
	headers["Connection"] = []string{"Keep-Alive"}
	uid, err := uuid.NewV4()
	if err != nil {
		return
	}
	headers["RequestId"] = []string{uid.String()}
	headers["Request-Module"] = []string{"Naming"}
	headers["Content-Type"] = []string{"application/x-www-form-urlencoded;charset=utf-8"}

	injectSecurityInfo(server, params)

	var response *http.Response
	response, err = server.httpAgent.Request(method, url, headers, server.timeoutMs, params)
	if err != nil {
		return
	}
	var bytes []byte
	bytes, err = ioutil.ReadAll(response.Body)
	defer response.Body.Close()
	if err != nil {
		return
	}
	result = string(bytes)
	if response.StatusCode == 200 {
		return
	} else {
		err = errors.New(fmt.Sprintf("request return error code %d", response.StatusCode))
		return
	}
}

callServer方法通过injectSecurityInfo注入SecurityInfo，通过server.httpAgent.Request(method, url, headers, server.timeoutMs, params)执行请求

ReqConfigApi

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) ReqConfigApi(api string, params map[string]string, headers map[string]string, method string, timeoutMS uint64) (string, error) {
	srvs := server.serverList
	if srvs == nil || len(srvs) == 0 {
		return "", errors.New("server list is empty")
	}

	injectSecurityInfo(server, params)

	//only one server,retry request when error
	var err error
	var result string
	if len(srvs) == 1 {
		for i := 0; i < constant.REQUEST_DOMAIN_RETRY_TIME; i++ {
			result, err = server.callConfigServer(api, params, headers, method, getAddress(srvs[0]), srvs[0].ContextPath, timeoutMS)
			if err == nil {
				return result, nil
			}
			log.Printf("[ERROR] api<%s>,method:<%s>, params:<%s>, call domain error:<%s> , result:<%s> \n", api, method, utils.ToJsonString(params), err.Error(), result)
		}
		return "", err
	} else {
		index := rand.Intn(len(srvs))
		for i := 1; i <= len(srvs); i++ {
			curServer := srvs[index]
			result, err = server.callConfigServer(api, params, headers, method, getAddress(curServer), curServer.ContextPath, timeoutMS)
			if err == nil {
				return result, nil
			}
			log.Printf("[ERROR] api<%s>,method:<%s>, params:<%s>, call domain error:<%s> , result:<%s> \n", api, method, utils.ToJsonString(params), err.Error(), result)
			index = (index + i) % len(srvs)
		}
		return "", err
	}
}

ReqConfigApi方法通过injectSecurityInfo注入SecurityInfo，通过server.callConfigServer执行请求，对于srvs有多个地址的则随机选择一个index执行，执行失败则切换下一个

ReqApi

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) ReqApi(api string, params map[string]string, method string) (string, error) {
	srvs := server.serverList
	if srvs == nil || len(srvs) == 0 {
		return "", errors.New("server list is empty")
	}

	injectSecurityInfo(server, params)

	//only one server,retry request when error
	if len(srvs) == 1 {
		for i := 0; i < constant.REQUEST_DOMAIN_RETRY_TIME; i++ {
			result, err := server.callServer(api, params, method, getAddress(srvs[0]), srvs[0].ContextPath)
			if err == nil {
				return result, nil
			}
			log.Printf("[ERROR] api<%s>,method:<%s>, params:<%s>, call domain error:<%s> , result:<%s> \n", api, method, utils.ToJsonString(params), err.Error(), result)
		}
		return "", errors.New("retry " + strconv.Itoa(constant.REQUEST_DOMAIN_RETRY_TIME) + " times request failed!")
	} else {
		index := rand.Intn(len(srvs))
		for i := 1; i <= len(srvs); i++ {
			curServer := srvs[index]
			result, err := server.callServer(api, params, method, getAddress(curServer), curServer.ContextPath)
			if err == nil {
				return result, nil
			}
			log.Printf("[ERROR] api<%s>,method:<%s>, params:<%s>, call domain error:<%s> , result:<%s> \n", api, method, utils.ToJsonString(params), err.Error(), result)
			index = (index + i) % len(srvs)
		}
		return "", errors.New("retry " + strconv.Itoa(constant.REQUEST_DOMAIN_RETRY_TIME) + " times request failed!")
	}
}

ReqApi方法通过injectSecurityInfo注入SecurityInfo，通过server.callConfigServer执行请求，对于srvs有多个地址的则随机选择一个index执行，执行失败则切换下一个

initRefreshSrvIfNeed

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) initRefreshSrvIfNeed() {
	if server.endpoint == "" {
		return
	}
	server.refreshServerSrvIfNeed()
	go func() {
		time.Sleep(time.Duration(1) * time.Second)
		server.refreshServerSrvIfNeed()
	}()

}

initRefreshSrvIfNeed方法执行server.refreshServerSrvIfNeed()，然后异步执行server.refreshServerSrvIfNeed()

refreshServerSrvIfNeed

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) refreshServerSrvIfNeed() {
	if utils.CurrentMillis()-server.lastSrvRefTime < server.vipSrvRefInterMills && len(server.serverList) > 0 {
		return
	}

	var list []string
	urlString := "http://" + server.endpoint + "/nacos/serverlist"
	result := server.httpAgent.RequestOnlyResult(http.MethodGet, urlString, nil, server.timeoutMs, nil)
	list = strings.Split(result, "\n")
	log.Printf("[info] http nacos server list: <%s> \n", result)

	var servers []constant.ServerConfig
	for _, line := range list {
		if line != "" {
			splitLine := strings.Split(strings.TrimSpace(line), ":")
			port := 8848
			var err error
			if len(splitLine) == 2 {
				port, err = strconv.Atoi(splitLine[1])
				if err != nil {
					log.Printf("[ERROR] get port from server:<%s>  error: <%s> \n", line, err.Error())
					continue
				}
			}
			servers = append(servers, constant.ServerConfig{IpAddr: splitLine[0], Port: uint64(port), ContextPath: constant.WEB_CONTEXT})
		}
	}
	if len(servers) > 0 {
		if !reflect.DeepEqual(server.serverList, servers) {
			server.Lock()
			log.Printf("[info] server list is updated, old: <%v>,new:<%v> \n", server.serverList, servers)
			server.serverList = servers
			server.lastSrvRefTime = utils.CurrentMillis()
			server.Unlock()
		}

	}

	return
}

refreshServerSrvIfNeed方法判断距离server.lastSrvRefTime是否超过server.vipSrvRefInterMills，超过则执行请求获取serverlist，然后判断serverList是否变更，变更的话则更新serverList及lastSrvRefTime

GetServerList

nacos-sdk-go-v0.3.2/common/nacos_server/nacos_server.go

func (server *NacosServer) GetServerList() []constant.ServerConfig {
	return server.serverList
}

GetServerList方法直接返回server.serverList

小结

NacosServer定义了securityLogin、serverList、httpAgent、timeoutMs、endpoint、lastSrvRefTime、vipSrvRefInterMills属性；它提供了NewNacosServer、ReqConfigApi、ReqApi、GetServerList等方法

doc

nacos_server

来源：oschina

链接：https://my.oschina.net/go4it/blog/4328043

标签

Nacos

github

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