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

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