v0.0.1 (#8)

Co-authored-by: Tasnim Kabir Sadik <tksadik92@gmail.com>
Reviewed-on: wrenn/sandbox#8

internal/layout/layout.go

@@ -0,0 +1,58 @@
+package layout
+
+import (
+	"path/filepath"
+
+	"github.com/jackc/pgx/v5/pgtype"
+
+	"git.omukk.dev/wrenn/sandbox/internal/id"
+)
+
+// IsMinimal reports whether the given team and template IDs represent the
+// built-in "minimal" template (both all-zeros).
+func IsMinimal(teamID, templateID pgtype.UUID) bool {
+	return teamID.Bytes == id.PlatformTeamID.Bytes && templateID.Bytes == id.MinimalTemplateID.Bytes
+}
+
+// TemplateDir returns the on-disk directory for a template.
+//
+//	minimal (zeros, zeros): {wrennDir}/images/minimal
+//	all others:             {wrennDir}/images/teams/{base36(teamID)}/{base36(templateID)}
+func TemplateDir(wrennDir string, teamID, templateID pgtype.UUID) string {
+	if IsMinimal(teamID, templateID) {
+		return filepath.Join(wrennDir, "images", "minimal")
+	}
+	return filepath.Join(wrennDir, "images", "teams",
+		id.UUIDToBase36(teamID.Bytes),
+		id.UUIDToBase36(templateID.Bytes))
+}
+
+// TemplateRootfs returns the path to a template's rootfs.ext4.
+func TemplateRootfs(wrennDir string, teamID, templateID pgtype.UUID) string {
+	return filepath.Join(TemplateDir(wrennDir, teamID, templateID), "rootfs.ext4")
+}
+
+// PauseSnapshotDir returns the directory for a paused sandbox's snapshot files.
+func PauseSnapshotDir(wrennDir, sandboxID string) string {
+	return filepath.Join(wrennDir, "snapshots", sandboxID)
+}
+
+// SandboxesDir returns the directory for running sandbox CoW files.
+func SandboxesDir(wrennDir string) string {
+	return filepath.Join(wrennDir, "sandboxes")
+}
+
+// KernelPath returns the path to the Firecracker kernel.
+func KernelPath(wrennDir string) string {
+	return filepath.Join(wrennDir, "kernels", "vmlinux")
+}
+
+// ImagesRoot returns the root images directory.
+func ImagesRoot(wrennDir string) string {
+	return filepath.Join(wrennDir, "images")
+}
+
+// TeamsDir returns the directory containing all team template subdirectories.
+func TeamsDir(wrennDir string) string {
+	return filepath.Join(wrennDir, "images", "teams")
+}