Ship custom tmpfiles.d configuration to avoid man-db cache removal

The default /usr/lib/tmpfiles.d/man-db.conf configuration includes:

  d /var/cache/man 0755 man man 1w

The systemd-tmpfiles-clean.timer runs 15 minutes after system bootup
(and then once per day). On our live system the mandb cache directory
/var/cache/man dates to the build time of the ISO, which of course
usually is older than one week. Then as soon as the
systemd-tmpfiles-clean.service is executed the mandb cache gets removed
and apropos(1) no longer works (at least until mandb gets executed
again).

Avoid this /var/cache/man removal by overriding the default
configuration file with a /etc/tmpfiles.d/man-db.conf configuration that
doesn't set the age option ("1w").

Credits to @2f2a for the bug report and @jkirk for assistance in debugging

Closes: grml/grml#201
Thanks: 2f2a and Darshaka Pathirana

etc/grml/fai/config/files/etc/tmpfiles.d/man-db.conf/GRMLBASE

@@ -0,0 +1,6 @@
+# This file was deployed via grml-live's
+# ${GRML_FAI_CONFIG}/config/scripts/GRMLBASE/85-systemd script, using
+# ${GRML_FAI_CONFIG}/config/files/etc/tmpfiles.d/man-db.conf/GRMLBASE
+
+# Override default (age set to 1w) to avoid disappearing mandb caches
+d /var/cache/man 0755 man man -

etc/grml/fai/config/scripts/GRMLBASE/85-systemd

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Filename:      ${GRML_FAI_CONFIG}/config/scripts/GRMLBASE/85-systemd
+# Purpose:       configure systemd and related services
+# Authors:       grml-team (grml.org), (c) Michael Prokop <mika@grml.org>
+# Bug-Reports:   see http://grml.org/bugs/
+# License:       This file is licensed under the GPL v2 or any later version.
+################################################################################
+
+set -u
+set -e
+. "$GRML_LIVE_CONFIG"
+
+fcopy -M -i -B -v -r /etc/tmpfiles.d
+
+## END OF FILE #################################################################
+# vim:ft=sh expandtab ai tw=80 tabstop=4 shiftwidth=2