I wrote a pretty simple service:
[Unit] Description=Service on interface %I [Service] Type=oneshot RemainAfterExit=yes ExecStart=/usr/lib/project/my_script.sh start %I [Install] WantedBy=multi-user.target Which I start like systemclt start myservice@net0, where net0 is a network interface. How can I restart the service every time the network interface is restarted?
You can have your systemd unit bind (BindTo) and depend on (DependsOn) the .device unit for the corresponding network interface (which is automatically loaded) for the said interface as so:
[Unit] Description=Service on interface %I BindsTo=sys-subsystem-net-devices-%i.device After=sys-subsystem-net-devices-%i.device [Service] Type=oneshot RemainAfterExit=yes ExecStart=/usr/lib/project/my_script.sh start %I [Install] WantedBy=multi-user.target You'll probably want to have the unit's dependency formalized by adding Wants and After if your custom unit expects to have the network interface actually online by adding these in the [Unit] section:
Wants=network-online.target After=network-online.target NB: You can verify that .device units are loaded by doing systemctl list-units --type=device.
Probably this could work: https://clinta.github.io/run-service-on-ip-change/
# /etc/systemd/system/ip-change-mon.service [Unit] Description=IP Change Monitor Wants=network.target After=network-online.target [Service] ExecStart=:/bin/bash -c "ip mon addr | sed -nu -r \'s/.*[[:digit:]]+:[[:space:]]+([^[:space:]]+).*/\\1/p\' | while read iface; do systemctl restart ip-changed@${iface}.target; done" [Install] WantedBy=multi-user.target default.target 