add copyright header
diff --git a/buildkite/pipelines/bazelci.py b/buildkite/pipelines/bazelci.py
index 7908759..11f8d6f 100644
--- a/buildkite/pipelines/bazelci.py
+++ b/buildkite/pipelines/bazelci.py
@@ -1,3 +1,17 @@
+# Copyright 2018 The Bazel Authors. All rights reserved.
+#
+# 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.
+
from __future__ import print_function
import argparse
import codecs
