How-to: Headless Pi easy setup

October 20, 2020

Raspberry Pi, SD card, PSU, card reader and a laptop with WiFi and Internet – set up and deploy without ever using any local peripherals (unless you can call its power supply a peripheral)

While this set of instructions is easily found all over the web I’ve put it in one place for my own reference. Use it if you like, I will be – repeatedly.

Steps

Image your SD card
Enable SSH and a WiFi connection
Boot the Pi
Connect over WiFi and login
Setup a few basics
Start using your headless Pi

Instructions

1. Image your SD card

Download Raspberry Pi Imager (I used v1.3 from here) and install it.
Plug in your SD card reader
Insert your SD card
Run Raspberry Pi Imager and click Choose OS

Select “Raspberry Pi OS Lite (32-bit)”
Click Choose SD card and select the SD card from the list that appears
Click Write
Allow the utility to write the image to the SD card
Allow the utility to verify the image on the SD card
When it tells you to remove the card, remove it

2. Enable SSH and a WiFi connection

Re-insert the SD card into the card reader then open the drive – it should be named “boot”
Create an empty text file with no extension, save it in the root level/folder of the “boot” volume, call it “SSH” (without the quotes)
Create another empty text file in the same root folder and call it wpa_supplicant.conf
Edit your new wpa_supplicant.conf file and copy the following into it

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="<INSERT YOUR SSID>"
    psk="<INSERT YOUR KEY>"
    id_str="home"
}

Edit your new wpa_supplicant.conf file to replace <SSID> and <KEY> with your wireless network name (SSID) and its password (KEY) – keep the quotes
Save and close the file
Properly eject the SD card

3. Boot the Pi

Insert the SD card into the Pi
Plug the Pi into a suitable power supply

4. Connect over WiFi and login

In order to connect over WiFi you will need to know the IP address of your Pi. There are a number of ways to do this depending on what tools you have available and what your WiFi router/access point can tell you.

I use isc-dhcp-server running on an Ubuntu Linux box so I log into that and issue a dhcp-lease-list command which lists all address leases on the network. It’s a relatively easy task to compare the list from before booting the Pi to the list afterwards to find the entry that relates to the newest host called “raspberrypi”.

You may find that entry easy to find in your router’s DHCP table. Alternatively, you may be able to scan your network for IP addresses in use – especially if you scan for open ports numbered “22” with a tool such as the Angry IP Scanner available here.

Once you know the IP address open a command line terminal (on MacOS simply use searchlight to open “Terminal”)

on Windows open the Command Prompt tool from the start menu

and type

ssh <ip-address> -l pi

replacing <ip-address> with the IP address you discovered above

On pressing ENTER you may be asked whether you want to add a key to your hosts file – reply “yes” and press ENTER again.

You should now be connected to your Raspberry Pi and looking at a prompt asking for the password for the user “pi”. By default, at the time of writing, the password for this installation of Raspbian is “raspberry” – type it without the quotes and press ENTER.

You should be successfully connected in an SSH session and looking at a prompt that says something like

pi@raspberrypi:~ $

5. Setup a few basics

Your Raspberry Pi is ready to use but I’d advise doing the following before getting started on your first project:

change the hostname
change the default password from “raspberry” – now you’ve enabled SSH anyone who knows the Raspberry Pi world knows that username-password combination
change the default username from “pi”
update all installed software versions

To change the hostname, type

sudo raspi-config

Select 2 from the menu that appears, then accept the warning with ENTER before deleting “raspberrypi” as the current hostname and entering something more meaningful like “server1” or “myserver”. Press ENTER then select <Finish> using the cursor keys and <Yes> to reboot.

Log back in as before using the same password

ssh <ip-address> -l pi

Then change the username to something that means something to you. To do so requires you to log into the Pi using an account that’s not the one you want to rename, so we’ll need to enable the root account for ssh login:

sudo passwd root

and set a password by following the prompts on screen. Remember the password.

Then, to edit the SSH configuration, type

sudo nano /etc/ssh/sshd_config

And add a line in the “Authentication” section of the file as follows:

PermitRootLogin yes

Next, exit the nano editor with Ctrl + X, answer “yes” to save and ENTER to overwrite the same filename. Then restart SSH and log out:

sudo systemctl restart sshd
logout

Log back in but this time as root, using the password set above:

ssh <ip-address> -l root

And change the username of the “pi” account to one of your choosing. Remember it:

usermod -l <yourname> pi

If an error is received because the pi user is running a process: “User pi is current used by process nnn” then kill the process and run the command again:

kill nnn && usermod -l <yourname> pi

Next rename the home folder to match the new username, and logout:

usermod -m -d /home/<yourname> <yourname>
logout

Log back in using the newly-named account and the same password as when the account was called “pi” (likely still “raspberry”):

ssh <ip-address> -l <yourname>

Then change the password by following the prompts shown after typing the command below (remember the password you choose):

passwd

Finally, disable root access to leave the system a little more secure by editing the previously added line to comment it out:

sudo nano /etc/ssh/sshd_config

Comment out by changing the “PermitRootLogin yes” to:

#PermitRootLogin yes

or just delete it altogether. Exit nano and save as above, and restart SSH so the changes take effect:

sudo systemctl restart sshd

At this stage I also usually ensure everything is up-to-date:

sudo apt update
sudo apt upgrade
sudo apt full-upgrade

Finally, I like to set a reservation on my DHCP server so that the Pi always gets the same IP address. That’s beyond the scope of this post but you could try “Googling DHCP reservation on <your router type>”

Your headless Raspberry Pi is ready to go

If you need to disable WiFi edit the boot config file:

sudo nano /boot/config.txt

to include the following line in the [all] section

dtoverlay=disable-wifi

You’ll need to reboot for it to take effect:

sudo reboot