--- /dev/null
+#!/bin/sh
+set -e
+
+test "$1" = 'install' || exit 0
+test -z "$2" || exit 0
+
+# not upgrading
+for i in Gdnscache Gdnslog; do
+ getent passwd $i >/dev/null ||
+ adduser --quiet --system --force-badname --shell /bin/false --group \
+ --home /nonexistent --no-create-home $i || exit 1;
+done