[Unit]
Description=PowerDNS Recursor
Documentation=man:pdns_recursor(1) man:rec_control(1)
Documentation=https://doc.powerdns.com
Wants=network-online.target nss-lookup.target
Before=nss-lookup.target
After=network-online.target

[Service]
ExecStart=/usr/sbin/pdns_recursor --daemon=no --write-pid=no --disable-syslog --log-timestamp=no
User=pdns-recursor
Group=pdns-recursor
Type=notify
Restart=on-failure
StartLimitInterval=0
RuntimeDirectory=pdns-recursor
SyslogIdentifier=pdns-recursor

# Tuning
LimitNOFILE=16384

# Sandboxing
CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_CHOWN
AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_CHOWN
LockPersonality=true
NoNewPrivileges=true
PrivateDevices=true
PrivateTmp=true
# Setting PrivateUsers=true prevents us from opening our sockets
ProtectClock=true
ProtectControlGroups=true
ProtectHome=true
ProtectHostname=true
ProtectKernelLogs=true
ProtectKernelModules=true
ProtectKernelTunables=true
ProtectSystem=full
RestrictAddressFamilies=AF_UNIX AF_INET AF_INET6
RestrictNamespaces=true
RestrictRealtime=true
RestrictSUIDSGID=true
SystemCallArchitectures=native
SystemCallFilter=~ @clock @debug @module @mount @raw-io @reboot @swap @cpu-emulation @obsolete

[Install]
WantedBy=multi-user.target