Post-installation

Set up systemd services and shell completions so dnsmonster runs on system startup.

After installing dnsmonster, a few extra steps make it run automatically on system startup. These are not part of the installation process by default.

Systemd service

On a modern distribution — Debian, Ubuntu, Fedora, Arch, RHEL — you are almost certainly running systemd. To run dnsmonster as a service, create /etc/systemd/system/dnsmonster.service and define your unit there. The service name is arbitrary.

cat > /etc/systemd/system/dnsmonster.service << EOF
[Unit]
Description=Dnsmonster Service
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
Restart=always
RestartSec=3
ExecStart=/sbin/dnsmonster --config /etc/dnsmonster.ini

[Install]
WantedBy=multi-user.target

EOF

The unit above reads /etc/dnsmonster.ini as its configuration file. See the configuration section for how that file is generated.

To start the service and enable it at boot:

sudo systemctl enable --now dnsmonster.service

One instance per interface

You can also build a templated unit that takes the interface name dynamically and runs one dnsmonster instance per interface:

cat > /etc/systemd/system/dnsmonster@.service << EOF
[Unit]
Description=Dnsmonster Service
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
Restart=always
RestartSec=3
ExecStart=/sbin/dnsmonster --devName=%i --config /etc/dnsmonster.ini

[Install]
WantedBy=multi-user.target

EOF

To run it for the loopback interface (lo):

sudo systemctl enable --now dnsmonster@lo.service

This only works if the configuration file does not also specify a dnstap socket or a local pcap file as input — a run takes exactly one input.