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/metropolis/cli/metroctl/core/ca_tofu.go b/metropolis/cli/metroctl/core/ca_tofu.go
index b578aa6..3f3c135 100644
--- a/metropolis/cli/metroctl/core/ca_tofu.go
+++ b/metropolis/cli/metroctl/core/ca_tofu.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
package core
import (
diff --git a/metropolis/cli/metroctl/core/config.go b/metropolis/cli/metroctl/core/config.go
index d22dd9a..38862af 100644
--- a/metropolis/cli/metroctl/core/config.go
+++ b/metropolis/cli/metroctl/core/config.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
package core
import (
diff --git a/metropolis/cli/metroctl/core/core.go b/metropolis/cli/metroctl/core/core.go
index 545a408..8e7e196 100644
--- a/metropolis/cli/metroctl/core/core.go
+++ b/metropolis/cli/metroctl/core/core.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
// Package core contains parts of metroctl which do significant amounts of work
// beyond just providing a CLI for them.
// This package is intended to be used for integrating with functions provided
diff --git a/metropolis/cli/metroctl/core/install.go b/metropolis/cli/metroctl/core/install.go
index 4175e22..190f66a 100644
--- a/metropolis/cli/metroctl/core/install.go
+++ b/metropolis/cli/metroctl/core/install.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
package core
import (
diff --git a/metropolis/cli/metroctl/core/rpc.go b/metropolis/cli/metroctl/core/rpc.go
index 91d5175..8b377f5 100644
--- a/metropolis/cli/metroctl/core/rpc.go
+++ b/metropolis/cli/metroctl/core/rpc.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
package core
import (