In case of non 200 response return error

network/resolver/http/http.go

@@ -3,6 +3,7 @@ package http
 
 import (
 	"encoding/json"
+	"errors"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -58,7 +59,9 @@ func (r *Resolver) Resolve(name string) ([]*resolver.Record, error) {
 		return nil, err
 	}
 	defer rsp.Body.Close()
-
+	if rsp.StatusCode != 200 {
+		return nil, errors.New("non 200 response")
+	}
 	b, err := ioutil.ReadAll(rsp.Body)
 	if err != nil {
 		return nil, err