Setting up static IP for sensor ethernet connection, ubuntu 20.04

Question

I need to set up an ethernet connection to a LIDAR, the steps to do so are:

Without the sensor connected to PC

sudo ip addr add 10.5.5.1/24 dev enp12s0

where enp12s0 is the name of my computers ethernet network interface, found by ifconfig.

Then connect the sensor and

sudo ip link set enp12s0 up
sudo dnsmasq -C /dev/null -kd -F 10.5.5.50,10.5.5.100 -i enp12s0 --bind-dynamic

I was curious if I could automate this? I have tried changing the netplan yaml config file, as well as adding wired connection types through gnomes network interface gui. But I can't seem to get it working.

My hope is to be able to make a profile where I can click on the wired connections in gnome and select this instead of having to redo the above steps all the time. How would I go about doing this?

Note: this is for ubuntu 20.04 LTS.

Answer 1

There may be more elegant ways to do it, but you could write a script for NetworkManager-dispatcher to trigger on connection change.

The dispatcher will give the interface and event as input and also sets up some convenient environment variables for you to use.

A minimal "working" example would be something like this:

/etc/NetworkManager/dispatcher.d/<script_name>

#!/bin/sh

interface="$1"
action="$2"

interfacename=enp12s0
uuid="<uuid of the desired connection>"

if [ "$action" = "up" ] && [ "$interface" = "$interfacename" ] && [ "$CONNECTION_UUID" = "$uuid" ]; then
    # Do your thing
fi

Obviously, you can undo any changes in a similar fashion when disabling the connection/profile.

Make sure the permissions are correct (not world-writable etc.) and that it's owned by root.

I haven't tested which events are fired when changing the wired profile, but at least changing wireless network will fire a connectivity-change followed by a down with CONNECTION_UUID set to the old network, followed by an up with CONNECTION_UUID set to the new network.