all: add copyright header comments

Author: creachadair

cmd/go-cache-plugin/commands.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 package main
 
 import (

cmd/go-cache-plugin/go-cache-plugin.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 // Program gocache implements the experimental GOCACHEPROG protocol over an S3
 // bucket, for use in builder and CI workers.
 package main

cmd/go-cache-plugin/help.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 package main
 
 import "github.com/creachadair/command"

godeps/godeps.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 //go:build go_mod_tidy_deps
 
 // Package godeps is a pseudo-package for tracking Go tool dependencies that

internal/s3util/s3util.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 // Package s3util defines some helpful utilities for working with S3.
 package s3util
 

internal/s3util/s3util_test.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 package s3util_test
 
 import (

revproxy/cache.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 package revproxy
 
 import (

revproxy/revproxy.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 // Package revproxy implements a minimal HTTP reverse proxy that caches files
 // locally on disk, backed by objects in an S3 bucket.
 //

s3cache/s3cache.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 // Package s3cache implements callbacks for a gocache.Server that store data
 // into an S3 bucket through a local directory.
 package s3cache

s3proxy/s3proxy.go

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 // Package s3proxy implements components of a Go module proxy that caches files
 // locally on disk, backed by objects in an S3 bucket.
 package s3proxy