feat: Add FreeBSD as a build target for releases (#603)

Approved-by: Antoine Cotten <antoine@unikraft.io>

.goreleaser-stable.yaml

@@ -121,6 +121,8 @@ builds:
 #@ targets = {
 #@   "linux-amd64": {"os": "linux", "arch": "amd64"},
 #@   "linux-arm64": {"os": "linux", "arch": "arm64"},
+#@   "freebsd-amd64": {"os": "freebsd", "arch": "amd64"},
+#@   "freebsd-arm64": {"os": "freebsd", "arch": "arm64"},
 #@   "darwin-arm64": {"os": "darwin", "arch": "arm64"},
 #@   "darwin-amd64": {"os": "darwin", "arch": "amd64"}
 #@ }
@@ -166,6 +168,8 @@ archives:
 #@ targets = [
 #@   "linux-amd64",
 #@   "linux-arm64",
+#@   "freebsd-amd64",
+#@   "freebsd-arm64",
 #@   "darwin-arm64",
 #@   "darwin-amd64"
 #@ ]

exec/process_freebsd.go

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2022, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file expect in compliance with the License.
+package exec
+
+import (
+	"syscall"
+)
+
+func hostAttributes() *syscall.SysProcAttr {
+	// the Setpgid flag is used to prevent the child process from exiting when
+	// the parent is killed
+	return &syscall.SysProcAttr{
+		Setpgid: true,
+	}
+}

machine/network/register_freebsd.go

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2022, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+package network
+
+// hostSupportedStrategies returns the map of known supported drivers for the
+// given host.
+// Currently stubbed out for FreeBSD.
+func hostSupportedStrategies() map[string]*Strategy {
+	return map[string]*Strategy{}
+}

machine/platform/register_freebsd.go

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2022, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+package platform
+
+func unixVariantStrategies() map[Platform]*Strategy {
+	return map[Platform]*Strategy{}
+}