run cache update in a transient service using systemd-run

- resolves #1318058

man-db-cache-update.service

@@ -0,0 +1,13 @@
+[Unit]
+DefaultDependencies=no
+After=local-fs.target
+Before=reboot.target shutdown.target halt.target
+JobTimeoutSec=15min
+
+[Service]
+Type=oneshot
+TimeoutStartSec=infinity
+Environment=MAN_NO_LOCALE_WARNING=1
+ExecStart=/usr/bin/mandb
+Nice=19
+IOWeight=20

man-db.spec

@@ -4,7 +4,7 @@
 Summary: Tools for searching and reading man pages
 Name: man-db
 Version: 2.7.6.1
-Release: 5%{?dist}
+Release: 6%{?dist}
 # GPLv2+ .. man-db
 # GPLv3+ .. gnulib
 License: GPLv2+ and GPLv3+
@@ -14,6 +14,7 @@ URL: http://www.nongnu.org/man-db/
 Source0: http://download.savannah.gnu.org/releases/%{name}/%{name}-%{version}.tar.xz
 Source1: man-db.crondaily
 Source2: man-db.sysconfig
+Source3: man-db-cache-update.service
 Patch0: man-db-2.7.6.1-change-owner-of-man-cache.patch
 
 # http://lists.nongnu.org/archive/html/man-db-devel/2017-01/msg00013.html
@@ -26,6 +27,9 @@ Provides: man-pages-reader = %{version}
 Provides: bundled(gnulib) = %{gnulib_ver}
 
 Requires: coreutils, grep, groff-base, gzip, less
+# for file trigger scriptlets
+Requires: systemd
+BuildRequires: systemd
 BuildRequires: gdbm-devel, gettext, groff, less, libpipeline-devel, zlib-devel
 BuildRequires: po4a, perl-interpreter, perl-version
 
@@ -89,6 +93,9 @@ install -D -p -m 0644 %{SOURCE2} $RPM_BUILD_ROOT%{_sysconfdir}/sysconfig/man-db
 # config for tmpfiles.d
 install -D -p -m 0644 init/systemd/man-db.conf $RPM_BUILD_ROOT/usr/lib/tmpfiles.d/.
 
+# man-db-cache-update.service
+install -D -p -m 0644 %{SOURCE3} $RPM_BUILD_ROOT%{_unitdir}/man-db-cache-update.service
+
 %find_lang %{name}
 %find_lang %{name}-gnulib
 
@@ -107,11 +114,12 @@ fi
 
 # update cache
 %transfiletriggerin -- %{_mandir}
-MAN_NO_LOCALE_WARNING=1 /usr/bin/mandb -q
+/usr/bin/systemd-run /usr/bin/systemctl start man-db-cache-update
 
 # update cache
 %transfiletriggerpostun -- %{_mandir}
-MAN_NO_LOCALE_WARNING=1 /usr/bin/mandb -q
+/usr/bin/systemd-run /usr/bin/systemctl start man-db-cache-update
+
 
 %files -f %{name}.lang -f %{name}-gnulib.lang
 %{!?_licensedir:%global license %%doc}
@@ -119,6 +127,7 @@ MAN_NO_LOCALE_WARNING=1 /usr/bin/mandb -q
 %doc README man-db-manual.txt man-db-manual.ps ChangeLog NEWS
 %config(noreplace) %{_sysconfdir}/man_db.conf
 %config(noreplace) /usr/lib/tmpfiles.d/man-db.conf
+%{_unitdir}/man-db-cache-update.service
 %{_sbindir}/accessdb
 %{_bindir}/man
 %{_bindir}/whatis
@@ -163,6 +172,10 @@ MAN_NO_LOCALE_WARNING=1 /usr/bin/mandb -q
 %config(noreplace) %{_sysconfdir}/sysconfig/man-db
 
 %changelog
+* Wed Nov 08 2017 Nikola Forró <nforro@redhat.com> - 2.7.6.1-6
+- run cache update in a transient service using systemd-run
+  resolves #1318058
+
 * Thu Aug 03 2017 Fedora Release Engineering <releng@fedoraproject.org> - 2.7.6.1-5
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_27_Binutils_Mass_Rebuild