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