feat: add script to automate license header insertion

Add `boilerplate.sh` script that automatically prepends license headers
to Go files that don't already have them.

hack/boilerplate.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+set -e
+
+for i in $(find ./cmd ./internal ./test ./hack -name "*.go"); do
+    if ! grep -q "Apache License" "$i"; then
+        printf '%s\n%s\n' "$(cat hack/boilerplate.go.txt)" "$(cat $i)" > temp && mv temp "$i"
+    fi
+done

internal/controller/resourcegroup/errors/resourcegroup.go

@@ -1,3 +1,15 @@
+// Copyright Amazon.com Inc. or its affiliates. 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. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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 errors
 
 import "fmt"

internal/dynamiccontroller/dynamic_controller_test.go

@@ -1,3 +1,15 @@
+// Copyright Amazon.com Inc. or its affiliates. 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. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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 dynamiccontroller
 
 import (

internal/graph/schema/schema.go

@@ -1,3 +1,15 @@
+// Copyright Amazon.com Inc. or its affiliates. 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. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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 schema
 
 import (