Run license check in CI

hack/add-license.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+# Copyright 2019 The Kubernetes Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+set -x
+set -e
+set -o pipefail
+set -o nounset
+
+if [[ -z "${1-}" ]] ; then
+  echo "Usage: $0 <mode>"
+  echo "Example: $0 check"
+  exit 1
+fi
+
+if [[ $1 == "check" || $1 == "run" ]]; then
+  mode=$1
+else
+  echo "Error: mode must be check or run"
+  exit 1
+fi
+
+args=(
+  -y 2022
+  -c "The Kubernetes Authors."
+  -f LICENSE_TEMPLATE
+  -ignore "kyaml/internal/forked/github.com/**/*"
+  -ignore "site/**/*"
+  -ignore "**/*.md"
+  -ignore "**/*.json"
+  -ignore "**/*.yml"
+  -ignore "**/*.yaml"
+  -v
+)
+if [[ $mode == "check" ]]; then
+  args+=(-check)
+fi
+
+addlicense "${args[@]}" .