treewide: add license header and enable haslicense linter

Change-Id: I873a8d4082d75e8f813d8a726a41187eea7a065e
Reviewed-on: https://review.monogon.dev/c/monogon/+/3825
Tested-by: Jenkins CI
Reviewed-by: Leopold Schabel <leo@monogon.tech>
diff --git a/cloud/equinix/wrapngo/duct_tape.go b/cloud/equinix/wrapngo/duct_tape.go
index d5dab7c..21581ce 100644
--- a/cloud/equinix/wrapngo/duct_tape.go
+++ b/cloud/equinix/wrapngo/duct_tape.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package wrapngo
 
 import (
diff --git a/cloud/equinix/wrapngo/metrics.go b/cloud/equinix/wrapngo/metrics.go
index fef506b..f6cabcb 100644
--- a/cloud/equinix/wrapngo/metrics.go
+++ b/cloud/equinix/wrapngo/metrics.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package wrapngo
 
 import (
diff --git a/cloud/equinix/wrapngo/wrapn.go b/cloud/equinix/wrapngo/wrapn.go
index 8ee654c..eee0b57 100644
--- a/cloud/equinix/wrapngo/wrapn.go
+++ b/cloud/equinix/wrapngo/wrapn.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 // Package wrapngo wraps packngo methods providing the following usability
 // enhancements:
 // - API call rate limiting
diff --git a/cloud/equinix/wrapngo/wrapngo_live_test.go b/cloud/equinix/wrapngo/wrapngo_live_test.go
index 166da4b..0ccce37 100644
--- a/cloud/equinix/wrapngo/wrapngo_live_test.go
+++ b/cloud/equinix/wrapngo/wrapngo_live_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package wrapngo
 
 import (