Computer Setup

Welcome To Ubuntu

Keep the default (English).

• You can setup other languages later, but use the default settings for the installation.

Accessibility

Keep the defaults.

• If you need some accessibility features to get through the installation select them but let me know.

Keyboard Layout

Keep the default (English US).

Internet Connection

Keep the default (Do not connect to the internet). Do not, under any circumstances, connect to the internet.

Try or Install Ubuntu

Keep the default (Install Ubuntu).

Type of Installation

Keep the default (Interactive Installation).

Applications

Keep the default (Extended Installation)

Optimize your Computer

Keep the default: (Unchecked Install third-party and Unchecked Download and install)

Disk Setup

Select Erase disk and Install Ubuntu. Do not choose any advanced features.

Create Your Account

Do not accept the defaults here.

• Enter your fullname for Your Name. This will auto-populate the other fields. DO NOT ACCEPT THE AUTO-FILLED VALUES
• Your computer's name: choose a name that is between 4-15 characters, all lowercase letters and numbers, starting with a letter.
• Your username: choose a username between 2 and 12 characters, all lowercase letters and numbers, starting with a letter.
• Choose a Strong password that you will remember
• The restrictions on computer name and username here are more restrictive than necessary but they make life easier in the future.

Select your timezone

Choose Chicago

• See if you can click on the map at the location of Chicago! (Or you can type it)
• Before proceeding, Location should say Chicago and Timezone should say America/Chicago

Ready to install

Click Install

(no term)

When the installation is complete restart the computer

Install the System76 Driver and nvidia drivers. All commands are entered in the Terminal:

sudo add-apt-repository -y ppa:system76-dev/stable
sudo apt install --no-install-recommends system76-driver
sudo apt install system76-driver-nvidia
sudo apt upgrade
reboot # will reboot your computer

• The sudo apt upgrade command above may actually downgrade some packages. We are now getting some hardware-specific packages from System76 rather than Ubuntu so the versions do not match. Precisely what benefits the System76 versions of the packages provide is a bit of an open question but System76 makes its own Linux Distribution and makes (or at least specs-out) the hardware so presumably their versions work better with our hardware (and at least we can complain to them when they don't).

Firefox is already installed. It comes from a package repository provided by Mozilla.

• I highly recommend that you install the UBlock Origin extension to block ads.

• Google Chrome is not part of Ubuntu so it must be downloaded directly from Google.
• It is also available as a snap, but these instructions assume we are avoiding snaps

• Download and install the google chrome package:

  wget -O /tmp/chrome.deb https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
  sudo apt install /tmp/chrome.deb
  

1. The most popular choice for recent MSR students.
   • Widely used.
   • Relatively easy to setup.
   • Supported (or controlled by) Microsoft, some plugins are not open source.

2. From the terminal:

   wget -O /tmp/code.deb "https://code.visualstudio.com/sha/download?build=stable&os=linux-deb-x64"
   sudo apt install /tmp/code.deb
   

3. Launch VSCode using code.
   • I opt-out of the telemetry collection (lower right) when first starting code.
4. More details on VSCode

If you like simplicity and modal text editing.

• Install with apt install vim (terminal-only) or apt install vim-gtk3 (with gui).
• There is also neovim, a popular fork of vim.
• There is a steep learning curve for vim.

Eight Megabytes and Constantly Swapping (this is a dated joke).

• My editor of choice: I use emacs with evil mode because …(insert hour-long discussion here)…
• spacemacs and doomemacs are popular pre-configured versions of emacs.
• sudo apt install emacs

So many others to choose from.

1. Many settings are contained in the Settings menu. I encourage you to explore them.
2. You can also install some additional tools. None are necessary (you can always edit configuration files)

   gnome-tweak-tool

   A GUI that provides several extra configuration options.

   gnome-extensions

   This package bundles several useful gnome extensions. Find out more at easily-developed extensions.

   dconf-editor

   Enables advanced editing of many settings.

• The gsettings command provides access to all settings via the command line.
• Settings are grouped into schemas, and individual options are stored as keys under a schema
• Use gsettings list-recursively to see all schemas and keys. The key is separated from the schema name by a space character
  • Use gsettings list-recursively | grep <something> to search for <something>
• You can get the value of a key with gsettings get <schema> <key>
• You can set the value of a key with gsettings set <schema> <key> <value>
• For example, to undo "natural scrolling" on the touchpad use gsettings set org.gnome.desktop.peripherals.touchpad natural-scroll false

• This method has the easiest installation because it is distributed by Ubuntu.
• It is also potentially less reliable because I do not know if the setup I describe will always work or if it is time or netID dependent (since it involves directly connecting to a server that was not mentioned by NUIT).
• Install the vpn client sudo apt install gp-saml-gui
• Connect to the vpn gp-saml-gui -vg -S vpn-connect2.northwestern.edu.
• If the above does not work, try to find the server using gp-saml-gui -v -S vpn-connect.northwestern.edu
  • vpn-connect.northwestern.edu is the official connection point provided by NUIT.
  • When your login it told me to connect to the gateway at vpn-connect2.northwestern.edu, it might tell you something different.

• This client works, but is currently a pain to install due to dependency issues, so I am not currently recommending it.
• To connect to Northwestern's VPN we use the free but unofficial program GlobalProtect-openconnect.

• Here are the installation instructions:

  sudo add-apt-repository ppa:yuezk/globalprotect-openconnect
  sudo apt install globalprotect-openconnect
  

• Run gpclient then use vpn-connect.northwestern.edu as the address.
• Enter your netId and password in the window that pops up.
• You will need Duo Authentication.

If you want to try your luck with the official proprietary client see these instructions.

• I have gotten the client to connect to VPN successfully; however, it is buggy. I have not successfully disconnected without manually killing the processes involved. By default, it also tries to connect to VPN every-time you login.
• It supports only older versions of Ubuntu.

These are instructions for using the printer in the Mechanical Engineering office and only work while on campus. You will need a printer code (referred to as <USERCODE>).

• Information on obtaining a printer code is available on canvas under "Resources/Printers".

• Disable printer discovery to avoid seeing extraneous printers

  sudo systemctl disable --now cups-browsed
  

• Setup the printer to use your <USERCODE>

  sudo lpadmin -p ME_Office -v "ipp://129.105.102.18/ipp" -m \
  "openprinting-ppds:0/ppd/openprinting/Ricoh/PDF/Ricoh-MP_C6004ex_PDF.ppd" \
  -o UserCode=Custom.<USERCODE>
  

  Replace <USERCODE> with your user code. (i.e., if your code is 1234, use Custom.1234)

• Enable the printer

  sudo cupsenable ME_Office
  sudo cupsaccept ME_Office
  

• The printer to print to is called ME_Office.

1. Setup the printer:

   sudo lpadmin -p CRB_Lab -v "hp:/net/HP_LaserJet_P4015?ip=129.105.69.122" -m \
   "hplip:0/ppd/hplip/HP/hp-laserjet_p4015x.ppd"
   

2. Enable the printer

   sudo cupsenable CRB_Lab
   sudo cupsaccept CRB_Lab
   

3. The printer to print to is called CRB_Lab.

Most computer applications that you use are built using libraries: collections of code that is generally useful across applications. Rather than duplicating this code every time it is needing (wasting both hard drive space and RAM), Ubuntu distributes one copy of each library which any application (or even another) library can use.

These dependencies create a problem: if a program (e.g., Inkscape) depends on library (e.g., libcairo) and these are made by completely different organizations, then a user who wants to use the program would have to install both the program and the library separately (e.g., go to the Inkscape website, download and install, read that it requires libcairo, then go download and install libcairo). It is not unusual for large programs to have hundreds of dependencies, so this process would become tiresome quickly. Then factor program and library versions and the situation becomes even more untenable.

Apt solves this dependency problem in two ways:

1. Providing a central repository of software (and it is quite extensive, search it at https://packages.ubuntu.com).
   • The versions of the software in the repository are designed to work together.
2. Tracking dependencies between programs and libraries.
   • For example, when installing a inkscape its dependencies will automatically be installed if not already present.
   • If you then try to uninstall a dependency of inkscape you will be unable to unless you also agree to uninstall inkscape and any other dependent programs.

By staying within the apt ecosystem using only official Ubuntu repositories you get well-tested software that is easy to install, update, and uninstall. How I wish I could end the story there!

Unfortunately, people (especially in robotics) often need packages that are not distributed by Ubuntu, for a few reasons:

1. Not everybody who creates software decides to put in the effort to create an Ubuntu package for it.
   • For key software Ubuntu may maintain its own packages but for others they won't.
2. A project you are trying to compile might need a different version of a library than is offered by Ubuntu.
   • Ubuntu introduces new software versions on a fixed release schedule (typically every 6 months).
   • Every two years Ubuntu issues an LTS version, which are the only version ROS officially supports.
   • Thus, at the end of the release cycle, software in Ubuntu LTS is almost two years old!
3. The software is proprietary and only packaged by the vendor.
   • We try to avoid this software but sometimes the sacrifice required too great.

In these cases alternative installation methods are required. One of your main goals when obtaining this software should be to minimize the effect such software has on the apt-managed part of the system.

Ubuntu enables apt to download packages from servers other than the officially provide ones, enabling third parties to distribute software through apt. Ubuntu also has it's own service, called Personal Package Archives (PPAs), which hosts custom third-party packages for downloading by apt. You have already used some non-Ubuntu repositories: for example ROS provides its own repositories.

If available, using an alternative apt repository enables you to maintain many of the advantages of apt, such as tracking dependencies and an easy uninstall method, while expanding the packages that are available. The disadvantage is that the packages in these repositories are not tested by the Ubuntu team, which can cause some installed programs to break. If the alternative repository, rather than just providing additional packages, provides an alternative version of a standard Ubuntu package the consequences can be widespread.

Fortunately, the goal of people who maintain alternative Ubuntu repositories is for their software to work on Ubuntu, so usually these alternative repositories do not cause issues. However, prior to adding such a repository you should

1. Trust the authors (by installing their package you are essentially allowing them to run code as root on your computer).
2. Ensure that you understand what is being installed and potential sources of conflict.
3. Through Pinning, you can control the repositories that get priority for each package.

Packages can also be distributed as standalone .deb packages and installed with apt. These packages can not generally be updated automatically via apt upgrade. However, some standalone .deb packages (such as the one for VSCode) actually function by adding an alternative repository to your system, which enables future updates.

Docker is containerization software that enables deploying a full Linux environment that is separate from the main system. For example, it can enable you to run Ubuntu 18.04 applications within Ubuntu 22.04. Discussing docker in detail is out-of-scope here, but from our perspective it provides a method for trying out a project while keeping it entirely separate from your system.

Overall, docker is less ergonomic for programs that you use every day on your system than some of these other methods, but it is a useful tool for deploying software to servers (or robots) and maintaining completely separate computing environments.

Python package management will come up a lot in this course. Furthermore doing things like trying to uninstall python or install another python version can cause great damage to the your system.

1. Prefer python packages installed via apt over all other python packages.
   • ROS is designed to work with the versions of the python packages in apt.
2. If what you are doing is unrelated to ROS, use a virtual environment.
3. If you want your packages easily available in ROS use pip3.
   • Cross your fingers that a dependency does not override a system dependency with a version that is incompatible.
   • With some work it is possible to use a venv with ROS.
4. NEVER install packages via anaconda or miniconda, no matter what you hear, read, or see from another source. DO NOT DO IT!

• Colcon is the build tool for ROS 2, but it can compile a variety of ROS and non-ROS packages.
• Many ROS packages are written in C++ which has no official package manager. There are some attempts (like vcpkg or conan) but they are far from standard or ubiquitous.
• Sometimes a ROS 2 package will only be released for an older ROS 2 version. Often it is possible to compile the package for a later version with minimal modification.
• For most packages, you can clone the package into a src directory and run colcon build. When you source that workspace everything you built in it will be available.
• You will need to retrieve dependencies with rosdep, manually install them via apt, or clone them into src/

Compiling "by hand" means following the instructions provided in the source code for compiling that particular project (or figuring out what to do from reading if there are no instructions). The main difficulty is obtaining all the dependencies. Once the dependencies are installed the main program can be installed.

If you install as root the files will be installed under the /usr/local prefix (usually). While this arrangement keeps the files separate from files managed by apt, it may be difficult to uninstall because the files are not usually tracked.

An alternative pattern is to do the following

1. Create a prefix directory. This directory mimics the structure under /usr but is typically placed in a user-accessible directory (e.g., /home/<user>/prefix).
2. Compile each depency while specifying /home/<user>/prefix as the install prefix and the place where the program should be installed
   • How to change the install prefix depends on build system and how that was implemented
   • For cmake, specify -DCMAKE_INSTALL_PREFIX=/home/user/prefix and -DCMAKE_PREFIX_PATH=/home/user/prefix when generating the build system.
3. Afterwards you can find the execuatables in /home/<user>/prefix/bin (and add them to your path if you would like).
4. The advantage of this method is you can install without root and can delete the whole prefix directory to uninstall.

If you need to modify source code, for the long run here is the procedure (assuming the project uses git):

1. Clone the repository
2. Create your own branch
3. Make your modifications
4. Push to a repository under your control (e.g., on github this will be a fork).
5. You may want to contribute your changes to the project.
6. You can now depend on your fork of the project and use whatever changes you made.

If you can compile the code you can also package it as a Debian package and install it, enabling it to be managed by apt.

• The ROS packaging tool bloom can be used (bloom generate rosdebian).
• The Debian packaging guide provides information on how to create Debian packages.