SPEC for a general useless ticking service with systemd unit and overridable rpm macros

tick.spec

# Variables that can be override on build time.
%{!?sleep: %define sleep 5}
%{!?name: %define name tick%{sleep}}
%{!?version: %define version 0.0}
%{!?release: %define release 1}
%{!?systemdinstalldir: %define systemdinstalldir /etc/systemd/system}
%{!?message: %define message come on, James}

# Some metadata required by an RPM package
Name: %name
Summary: Print a message every %{sleep}s
Version: %version
Release: %release
License: MIT

%description
%{name} is a simple useless script that echos a message every %{sleep} seconds.


%install

# create the executable from scratch in buildroot.
%{__mkdir} -p %{buildroot}%{_prefix}/bin

%{__cat} <<EOF> %{buildroot}/usr/bin/%{name}
#!/bin/bash

# say something, with timestamp, every %{sleep} seconds
while echo "\$@"; do
  sleep %{sleep}s
done
EOF

%{__chmod} 755 %{buildroot}%{_prefix}/bin/%{name}

# generate the systemd unit file to buildroot.
%{__mkdir} -p %{buildroot}%{systemdinstalldir}
%{__cat} <<EOF> %{buildroot}%{systemdinstalldir}/%{name}.service
[Unit]

[Install]
WantedBy=multi-user.target

[Service]
ExecStart=%{_prefix}/bin/%{name} %{message}
Restart=always
RestartSec=5
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=%n
EOF


%files
%{_prefix}/bin/%{name}
%{systemdinstalldir}/%{name}.service