Ubuntu Linux for Robotics · Lesson 91 of 96

Hardware deployment

Preparing a robot computer: images, services, updates, backups and rollback.

Estimated time · 60–90 min

Learning goals

What you will understand

Explain hardware deployment in your own words
Use it in a small workstation example
Verify the result instead of assuming it worked

Understand the idea first

The mental model

Deploying to real hardware means the robot must start by itself and be recoverable: install a minimal Ubuntu, add your packages from apt or a container image, create a systemd service for the bringup, set static network addresses, enable SSH with keys, and configure the firewall. Keep the configuration in Git or a script so a second robot can be made identically.

Update carefully: freeze package versions (apt-mark hold) on a working robot, test updates on a spare machine first, keep a backup image, and keep a rollback path (the previous container tag or a disk image). Never test new code first on an untethered robot.

Guided lesson

Work through these steps

1.
Open a terminal and record the current state before changing anything.
2.
Read the hardware deployment commands and predict what each one does.
3.
Run the commands one at a time and compare each output with your prediction.
4.
Write the commands that worked in a setup note you can repeat later.

Worked example

Read it before you run it

sudo apt-mark hold ros-lyrical-navigation2 ros-lyrical-nav2-bringup
# Stop a working set of packages from being upgraded by accident.
sudo systemctl enable --now robot-bringup.service
# Start the robot software at every boot.
sudo hostnamectl set-hostname robot1
# Give the computer a stable name.
sudo ufw allow from 192.168.1.0/24 to any port 22 proto tcp
# Allow SSH from the robot network only.
sudo dd if=/dev/nvme0n1 of=/mnt/backup/robot1.img bs=4M status=progress
# Back up the disk to an image (check the device names twice).

What the example is doing

1.Lines without sudo only inspect or change files you own; sudo authorizes a system-wide change.
2.Read command output before moving to the next line. Stop if names, versions, disks, or paths differ from the lesson.
3.Comments beginning with # explain safety checks and are not executed by the shell.

Watch it run · The robot's computer

See what this code does

The terminal types this lesson's practice solution and runs it. The scene shows the kind of robot behaviour that code drives. It plays by itself and loops.

Practice code

Now type it yourself

Open a terminal, run the starter line by line (or save it as practice.sh and run bash practice.sh), and replace every TODO with your own command.

# TODO: put ros-lyrical-navigation2 on hold so apt upgrade does not change it
apt-mark showhold

Expected output

The packages are marked as held

Stuck? Show the full solution (try it yourself first)

sudo apt-mark hold ros-lyrical-navigation2
apt-mark showhold

Expected result

How you know it worked

Each command completes without an unexplained error.
Your notes contain the command, the important output, and what it proves.

Practical exercise

Apply the lesson

Write a setup script that installs packages, creates the bringup service, sets the hostname and firewall, and run it on a second (virtual) machine to prove that the robot can be reproduced.

Before you continue

You recorded the starting state
Every command and output is understood
The change can be repeated from your notes

If something goes wrong

A command says permission denied.

Check ownership and permissions first. Do not add sudo unless the command changes a documented system location.

A command or package is not found.

Check spelling, Ubuntu version, enabled repositories, and whether the previous installation command succeeded.