Apply the Apache 2.0 license to all your .go files

apply-license.bash

#!/bin/bash
FILES=$(find . -name "*.go" -not -path "./vendor/*" -type f)
 
for f in $FILES
do
	echo "processing: $f"
ed -s $f << EOF
0a
// Copyright YEAR YOU
//
// 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.

.
w
EOF
done

Be sure to copy from the raw display -- not the colored/formatted display -- so as to include all empty lines.