Getting Wifi to Work on Ubuntu Server 20.04 on a Raspberry Pi 4

This guide is specifically for Ubuntu Server 20.04 on a Raspberrry Pi 4. This is the first thing I do after putting a fresh SD card into the Pi and giving it power.

how to get connected to the internet

I'm a renter and I just don't take the time to set up a wired network, as much as I fancy myself an amateur homelabber (which I think is already an amateur sysadmin?).

So the first thing I always have to do when I restart a raspberry pi build is try to get wifi working. I usually have to google it. Here's what you do without too much extra talking.

This guide assumes you have a sudo user account, and haven't messed with too much stuff yet, basically the first thing you do after you install from an SD card.

make sure the wifi card in your raspberry pi 4 doesn't have a goofy name

ls /sys/class/net

That will list some options. You're looking for something that starts with w probably. Mine was wlan0. I bet yours is too.

add your wifi network info to 50-cloud-init.yaml

This is a YAML configuration file. Being a YAML file, indentation is important. Make sure you use 4 spaces on lines that should be indented, not a tab. Just line things up like you see in the file.

I use vim to edit files. You can too. Just know that it has two modes. Hitting esc gets you out of insertion mode and back to the mode you're in when you first open the file. This is pretty safe. Use the keys HJKL to move your cursor around the file. Press I to be able to type. Here we go:

sudo vim /etc/netplan/50-cloud-init.yaml

Hold J to get to the bottom of the file.

Make a wifis: entry at the bottom, inline with the ethernets: line.

Your entry will look like this:

wifis:
    wlan0:
        optional: true
        dhcp4: true
        access-points:
            "YOUR-WIRELESS_NETWORK-HERE":
                password: "YOUR_NETWORKS-PASSWORD"

Now you've typed your settings in, how the heck do you save? First, hit esc to get out of insertion mode. Then type :wq to write and quit.

tell ubuntu to ignore the default config when the computer restarts

If you didn't read the top of the last file, check it out real quick less /etc/netplan/50-cloud-init.yaml. Hit q to quit reading.

We're going to create the file it suggests. Easy peasy.

sudo vim /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

and put the following line in it and save the file (hit I, type the code in, hit esc, type :wq)

network: {config: disabled}

reboot your pi and hope it works

That should be all you need to get hooked up. When you reboot, your pi should have connected to wifi automatically assuming you've got a straightforward setup.

sudo reboot