v2ray-core/release/config/systemd/v2ray.service

[Unit]
Description=V2Ray Service
After=network.target
Wants=network.target

[Service]
Type=simple
PIDFile=/var/run/v2ray.pid
ExecStart=/usr/bin/v2ray/v2ray -config /etc/v2ray/config.json
ExecStop=kill $(cat /var/run/v2ray.pid)
Restart=on-abnormal

[Install]
WantedBy=multi-user.target