Run license check in CI

.github/workflows/go.yml

@@ -29,6 +29,9 @@ jobs:
       env:
         KUSTOMIZE_DOCKER_E2E: false # don't need to do e2e tests for linting
 
+    - name: Verify boilerplate
+      run: make check-license
+
   test-linux:
     name: Test Linux
     runs-on: [ubuntu-latest]

Makefile

@@ -114,18 +114,12 @@ prow-presubmit-check: \
 
 .PHONY: license
 license: $(MYGOBIN)/addlicense
-	$(MYGOBIN)/addlicense \
-	  -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 \
-	  .
+	./hack/add-license.sh run
+
+.PHONY: check-license
+check-license: $(MYGOBIN)/addlicense
+	./hack/add-license.sh check
+
 
 .PHONY: lint
 lint: $(MYGOBIN)/golangci-lint $(builtinplugins)

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[@]}" .