Scriptlets
The systemd package provides a set of helper macros to handle systemd scriptlet operations. These macros support systemd "presets", as documented in Features/PackagePresets. Note that the %systemd_requires macro must not be used.
Requires(post): systemd Requires(preun): systemd Requires(postun): systemd BuildRequires: systemd [...] %post %systemd_post apache-httpd.service %preun %systemd_preun apache-httpd.service %postun %systemd_postun_with_restart apache-httpd.service
Some services do not support being restarted (e.g. D-Bus and various storage daemons). If your service should not be restarted upon upgrade, then use the following %postun scriptlet instead of the one shown above:
%postun %systemd_postun apache-httpd.service
If your package includes one or more systemd units that need to be enabled by default on package installation, they must be covered by the Fedora preset policy.
For details on what these macros evaluate to, refer to the following sources:
https://github.com/systemd/systemd/blob/master/src/core/macros.systemd.in,
https://github.com/systemd/systemd/blob/master/src/core/triggers.systemd.in and
http://www.freedesktop.org/software/systemd/man/daemon.html.
Packages migrating to a systemd unit file from a SysV initscript
When updating from a package containing a SysV initscript to a package containing a systemd unit file, we "start-over fresh" with default start and stop policy from the new package and do not migrate what the user had previously configured. For this reason, you can simply use the above scriptlets and not worry about converting the sysv information to something relevant to systemd.
Packages are strictly forbidden from migrating to systemd within updates to a Fedora release because migration will reset the user's choices about whether to start or stop the service. Migration is only allowed between Fedora releases.
