Write into a file the machine shares instead of over it, and reload a service that re-reads its configuration instead of restarting it (hq ADR 0102)

internal/system/arch.go

@@ -254,3 +254,9 @@ func (arch) ReloadUnits(ctx context.Context, run Runner) error {
 	_, err := run(ctx, "systemctl", "daemon-reload")
 	return err
 }
+
+// ReloadService tells a running unit to read its configuration again, without stopping it.
+func (arch) ReloadService(ctx context.Context, run Runner, unit string) error {
+	_, err := run(ctx, "systemctl", "reload", unit)
+	return err
+}