Add retry function to test utils (#661)

VERSION

@@ -1 +1 @@
-0.6.6-dev
+0.6.6

pkg/utils/retry.go

@@ -0,0 +1,27 @@
+// Copyright 2020-present Open Networking Foundation.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import "time"
+
+func Retry(count int, delay time.Duration, check func() bool) bool {
+	for attempt := 1; attempt != count; attempt++ {
+		if check() {
+			return true
+		}
+		time.Sleep(delay)
+	}
+	return false
+}