error if canot get db address

common/go/src/asapo_common/discovery/discovery.go

@@ -3,6 +3,7 @@ package discovery
 import (
 	"io/ioutil"
 	"net/http"
+	"errors"
 )
 
 type DiscoveryAPI struct {
@@ -15,6 +16,9 @@ func (api *DiscoveryAPI) GetMongoDbAddress() (string, error) {
 	if err != nil {
 		return "", err
 	}
+	if resp.StatusCode!=http.StatusOK {
+		return "", errors.New("cannot get mongodb server, status: "+resp.Status)
+	}
 	defer resp.Body.Close()
 	body, err := ioutil.ReadAll(resp.Body)
 	return string(body), err