[Unit]
Description=Nagios core
After=network.target local-fs.target

[Service]
Type=forking
User=nagios
Group=nagios
PIDFile=/run/nagios/nagios.pid
# Verify Nagios config before start as upstream suggested
ExecStartPre=/usr/bin/nagios -v /etc/nagios/nagios.cfg
ExecStart=/usr/bin/nagios -d /etc/nagios/nagios.cfg
ExecStop=/bin/kill -TERM ${MAINPID}
ExecStopPost=/bin/rm -f /var/spool/nagios/cmd/nagios.cmd
ExecReload=/bin/kill -HUP ${MAINPID}

[Install]
WantedBy=multi-user.target