discovery client check status (#375)

pkg/naming/discovery/discovery.go

@@ -374,7 +374,11 @@ func (d *Discovery) register(ctx context.Context, ins *naming.Instance) (err err
 		params.Add("addrs", addr)
 	}
 	params.Set("version", ins.Version)
-	params.Set("status", _statusUP)
+	if ins.Status == 0 {
+		params.Set("status", _statusUP)
+	} else {
+		params.Set("status", strconv.FormatInt(ins.Status, 10))
+	}
 	params.Set("metadata", string(metadata))
 	if err = d.httpClient.Post(ctx, uri, "", params, &res); err != nil {
 		d.switchNode()
@@ -471,7 +475,7 @@ func (d *Discovery) set(ctx context.Context, ins *naming.Instance) (err error) {
 	params := d.newParams(conf)
 	params.Set("appid", ins.AppID)
 	params.Set("version", ins.Version)
-	params.Set("status", _statusUP)
+	params.Set("status", strconv.FormatInt(ins.Status, 10))
 	if ins.Metadata != nil {
 		var metadata []byte
 		if metadata, err = json.Marshal(ins.Metadata); err != nil {

pkg/naming/naming.go

@@ -35,6 +35,8 @@ type Instance struct {
 	// Metadata is the information associated with Addr, which may be used
 	// to make load balancing decision.
 	Metadata map[string]string `json:"metadata"`
+	// Status instance status, eg: 1UP 2Waiting
+	Status int64 `json:"status"`
 }
 
 // Resolver resolve naming service