/
etcd_resolver.go
92 lines (77 loc) · 1.88 KB
/
etcd_resolver.go
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package discover
import (
"context"
"github.com/chriswoodcn/gocourse/examples/grpcdemo/grpc/lb"
"go.etcd.io/etcd/client/v3"
"google.golang.org/grpc/attributes"
"google.golang.org/grpc/resolver"
"log"
"sync"
)
type etcdResolver struct {
ctx context.Context
cancel context.CancelFunc
cc resolver.ClientConn
etcdClient *clientv3.Client
scheme string
ipPool sync.Map
}
func (e *etcdResolver) ResolveNow(resolver.ResolveNowOptions) {
log.Println("etcd resolver resolve now")
}
func (e *etcdResolver) Close() {
log.Println("etcd resolver close")
e.cancel()
}
func (e *etcdResolver) watcher() {
watchChan := e.etcdClient.Watch(context.Background(), "/"+e.scheme, clientv3.WithPrefix())
for {
select {
case val := <-watchChan:
for _, event := range val.Events {
switch event.Type {
case 0: // 0 是有数据增加
e.store(event.Kv.Key, event.Kv.Value)
log.Println("put:", string(event.Kv.Key))
e.updateState()
case 1: // 1是有数据减少
log.Println("del:", string(event.Kv.Key))
e.del(event.Kv.Key)
e.updateState()
}
}
case <-e.ctx.Done():
return
}
}
}
func (e *etcdResolver) store(k, v []byte) {
e.ipPool.Store(string(k), string(v))
}
func (e *etcdResolver) del(key []byte) {
e.ipPool.Delete(string(key))
}
func (e *etcdResolver) updateState() {
var addrList resolver.State
// 模拟权重设置
log.Println("etcdResolver updateSate called...")
var i = 1
e.ipPool.Range(func(k, v interface{}) bool {
tA, ok := v.(string)
if !ok {
return false
}
log.Printf("conn.UpdateState key[%v];val[%v]\n", k, v)
// 模拟设置权重
addr := resolver.Address{
BalancerAttributes: attributes.New(lb.WeightAttributeKey{}, lb.WeightAddrInfo{
Weight: i,
}),
Addr: tA,
}
addrList.Addresses = append(addrList.Addresses, addr)
i++
return true
})
e.cc.UpdateState(addrList)
}