Systemd service file for CentOS/Fedora

[carlbennett]

I've been using this service file with Systemd on Fedora since I started using this project earlier this year. It's always worked for me. I left the commented Exec lines because that's how it's documented to behave as a service, but I found them not necessary.

[Unit]
Description=AdGuard Home
Documentation=https://github.com/AdguardTeam/AdGuardHome
After=network.target

[Service]
Type=simple
User=root
WorkingDirectory=/opt/AdGuardHome
ExecStart=/opt/AdGuardHome/AdGuardHome
#KillSignal=SIGINT
#ExecStart=/opt/AdGuardHome/AdGuardHome -s start
#ExecRestart=/opt/AdGuardHome/AdGuardHome -s restart
#ExecStop=/opt/AdGuardHome/AdGuardHome -s stop
Restart=on-failure

[Install]
WantedBy=multi-user.target

[ameshkov]

Thank you!

Merging into #765