+ <para>To facilitate upgrades from a package
+ version that shipped only SysV init scripts to
+ a package version that ships both a SysV init
+ script and a native systemd service file, use
+ a fragment like the following:</para>
+
+ <programlisting>%triggerun -- foobar < 0.47.11-1
+if /sbin/chkconfig --level 5 foobar ; then
+ /bin/systemctl --no-reload enable foobar.service foobar.socket >/dev/null 2>&1 || :
+fi</programlisting>
+
+ <para>Where 0.47.11-1 is the first package
+ version that includes the native unit
+ file. This fragment will ensure that the first
+ time the unit file is installed it will be
+ enabled if and only if the SysV init script is
+ enabled, thus making sure that the enable
+ status is not changed. Note that
+ <command>chkconfig</command> is a command
+ specific to Fedora which can be used to check
+ whether a SysV init script is enabled. Other
+ operating systems will have to use different
+ commands here.</para>