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聊聊nacossdkgo的NacosServer

jiezi

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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