// 创建一个BackService
func NewBackService(serviceName string, poller *zmq.Poller, topo *zk.Topology) *BackService {
backSockets := NewBackSockets(poller)
service := &BackService{
ServiceName: serviceName,
backend: backSockets,
poller: poller,
topo: topo,
}
var evtbus chan interface{} = make(chan interface{}, 2)
servicePath := topo.ProductServicePath(serviceName)
endpoints, err := topo.WatchChildren(servicePath, evtbus)
if err != nil {
log.Println("Error: ", err)
panic("Reading Service List Failed: ")
}
go func() {
for true {
// 如何监听endpoints的变化呢?
addrSet := make(map[string]bool)
nowStr := time.Now().Format("@2006-01-02 15:04:05")
for _, endpoint := range endpoints {
// 这些endpoint变化该如何处理呢?
log.Println(utils.Green("---->Find Endpoint: "), endpoint, "For Service: ", serviceName)
endpointInfo, _ := topo.GetServiceEndPoint(serviceName, endpoint)
addr, ok := endpointInfo["frontend"]
if ok {
addrStr := addr.(string)
log.Println(utils.Green("---->Add endpoint to backend: "), addrStr, nowStr, "For Service: ", serviceName)
addrSet[addrStr] = true
}
}
service.backend.UpdateEndpointAddrs(addrSet)
// 等待事件
<-evtbus
// 读取数据，继续监听
endpoints, err = topo.WatchChildren(servicePath, evtbus)
}
}()
ticker := time.NewTicker(time.Millisecond * 1000)
go func() {
for _ = range ticker.C {
service.backend.PurgeEndpoints()
}
}()
return service
}
